KIT BUILDING TIPS

The Mini Bird E is a smaller version of the highly successful Sky Bench Lil' Bird 2 hand launch design that many builders convert to a speed 400 electric powered sailplane with great flying success. This smaller version builds exactly like all the Sky Bench Bird series, simple and quick. You will need to be careful when working with the 1/32" wing sheeting and Ca glue, the Ca will travel far and fast through the veins of the sheeting and glue your fingers to the sheeting quicker than you can blink an eye.

The following step by step instructions is the way I build, you may have a different approach and that is one of the fun things about building woodys. Please be aware that writing building instructions to a model airplane is sometimes like talking in English to a Spanish audience. The very best approach to building any woody is spend as much time as needed reviewing the construction plans to understand how and where the parts are placed. The worst thing you can do is dump all the parts out of the plastic bags at once. To review the parts, they do not need to be removed from the bags. All the parts are depicted on the plan, so why open a parts bag until it is needed ? To give you an idea of variances of building skills that can be found between the not so experienced and the experienced builders, an experienced builder like myself can build almost any kit without reading the written instructions. In my case, I consider taking time to read the building instructions is a waste of time, but I have been building woody models since I was six years old.

Start with the Wing.

Always place wax paper over the construction plan with pins in the four corners to hold the plans and wax paper flat to the building board.

Always trial fit parts before gluing them.

Place pieces of masking tape on the bottom side of the bottom sheeting where each rib will come in contact with the sheeting. The tape should be no longer than an inch on the bottom with tape protruding another inch which will be used to attach the bottom sheeting to the ribs and later the top sheeting to the ribs.

Pin the inner panel bottom front sheeting over the plan, trim if necessary. After the wing panels are joined together and the top sheeting is glued to the wing, the front edge of the top and bottom sheeting are sanded back to the front edge of the ribs prior to installing the Leading Edge pieces.

Use one of the ribs # 3 through # 7 as a guide to locate the placement of the Trailing Edge bottom sheeting. Note these ribs are shaped on the bottom to fit in between the front and rear bottom sheeting (top sheeting also). Pin the Trailing Edge down.

Using the same rib as above, use it to locate the spar location on top of the bottom front sheeting. Place the spar on the sheeting and the rib on top of the spar. The rib should fit between the front and trailing edges and over the spar. Place about 4 pins against the front side of the spar to create an alignment fence. Glue the spar to the bottom sheeting using the alignment pin fence as a guide. Never stick pins through the spar to hold it down.

Glue in the bottom 1/32" sheeting pieces at the root between the front and rear bottom sheeting. Note ribs # 1 and 2 are shaped to lay flat on the bottom and top sheeting. These ribs are shaped differently than all the remaining ribs.

Glue in ribs # 2 through # 7. Check to make sure the ribs rest on the bottom balsa sheeting, due to irregularities in spruce spar thicknesses, an oversized spar will not let the ribs rest on the bottom balsa sheeting properly. Use a file to enlarge the spar notch in the ribs as needed. Check the top spar notches at this time too. Ribs # 1 are glued in when attaching the two inner panels together to form the center dihedral joint prior to attaching the top sheeting.

For added spar strength, glue in vertical grain 1/8" wide balsa shear web pieces to the top of the bottom spar between ribs # 1 through # 4.

Glue in the top spar, be sure the vertical shear webs between rib # 1 and # 4 are flush with the bottom of the top spar. I always use weights on the top spar at this stage to insure the wing is flat and the spar is completely down in the rib spar notches.

Place weights on the ribs between the spar and trailing edge to hold the wing flat to the building board. Starting at rib # 4, use the tape previously installed to pull the bottom sheeting up tight against the bottom of the rib and glue with Ca.

Continue gluing the bottom sheeting to the ribs by alternating to rib # 3 and then rib # 5, etc.. If you start gluing the bottom sheeting at rib # 1, 2, 3, 5, 6, or 7 instead of rib #4, you will end up with a buckle in the sheeting and that will be a disaster.

Glue in the 1/32" balsa shear webs to the fronts of the top and bottom spars and the sides of the ribs and flush with the top of the spar. Use the extra 1/32" sheeting rectangle supplied in the wing sheet package to make the taller shear webs located between ribs # 8 thru # 11.

The outer tip panels are made in the same way as the inner panels. Install the 1/8" vertical balsa shear webs and the 1/32" sear webs on both sides of rib # 7 after the outer wing panel is joined to the inner panel with the plywood polyhedral brace WPB. Do not install the tip blocks until all four of the wing panels have been joined together and the top sheeting has been installed.

Join the outer tip panel to the inner panel by placing the inner panel on the work surface and use weights behind the spar to hold the wing down. The tip panel is raised 2 - 7/ 8 " at the trailing edge of rib # 13. Sand a bevel into the top and bottom tip panel spars and trial fit. Do this in small amounts so as not to sand too much off the spars. Cut rib # 7 along the back side of the spar with a zona saw and glue WPB in place. I use small bendable metal clamps available in the women's hair treatment department of most chain stores to hold the shear webs and plywood parts to the spars while gluing.

Install the 1/8" vertical shear webs on both sides of rib # 7 as shown on the plan between the spars and the remaining 1/32" shear webs to the sides of the spars.

Join the other tip panel to the remaining inner panel in the same manner.

Join the two inner panels by laying one panel on the work surface, use the weights again to hold the wing flat. The other inner panel is raised 2" at the trailing edge of rib # 7. Install both WDB parts to the sides of the spars and 1/8" vertical shear webs.

Cut to proper length and install both Ribs # 1

Install the two anti - crush blocks on each side of Ribs # 1. Sand a bevel in the top of them to match rib contour.

Use an electric drill to make the wing bolt holes as shown on the plans. Be careful not to cut the sides of WDB while drilling the hole.

After the wing panels are joined, install the top front sheeting and trailing edge to one inner panel. Use weights to insure a flat wing. The bottom trailing edge needs to be sanded with a Perma grit sander to create a nice bevel in the rear edge to accommodate the top trailing edge. See wing profile side view on fuselage plan.

Install the top front sheeting and trailing edge to the other inner panel.

Install the top sheeting and rear trailing edge to the tip panels and be sure to weight the panel down to keep the wing from being twisted. Use the masking tape to hold the top sheeting to the ribs at the front edge and weights above the spar. I use Sig wood glue for the top sheeting.

Install the leading edges and tip blocks. If you purchased a Perma Grit sander you will be able to sand out the leading edge and tip blocks in half the time of a regular sanding block and with better results. Final sanding on the leading edge should be done with spanwise strokes or you will have a wavy (changing) leading edge, which is not good. I use masking tape to hold the Leading edges on during gluing.

Any wing that is twisted will have less performance than a true wing. Place two yard sticks under each panel, site them for being parallel to each other to check on wing twist. A twisted wing means it is flying at two or more angles of incidence. A twisted wing means the plane wants to turn one way at slow speed and the opposite way at fast speed. Not good.

Next is the Fuselage.

The most important issue with the fuse sides is making sure the bottom edges of the sides are straight. This determines the wing incidence in relation to the stabilizer which in turn determines the flight performance and characteristics and the balancing point.

The second most important issue is the rear fuse sides have a left and a right side. Refer to plan where the push rods exit the fuse.

I like to make a pin fence to use as an alignment guide when gluing the front and rear fuse sides together.

To make an accurate pin fence use a straight edge ruler and be sure the pins are vertical, not slanting. This fence is also used to glue the 1/64" plywood doublers to the fuse sides.

Gluing the doublers is critical and care has to be taken to match the fuse tab holes in the 1/64" to the corresponding holes in the 1/16" balsa sides. Use a former before gluing as a guide and make sure the plywood doublers will end up on the inside of the fuse.

I use Ca to glue the 1/64" ply doubler to the fuse sides, the pin fence becomes a location guide and this is vital if you are using Thin Ca which will set up too fast to allow time to shuffle the doubler around to the proper position.

If you use wood glue on the doubler, the water based glue will cause the sides to dry with a pronounced curve. Not good.

One way to make a straight fuse (instead of a banana shaped fuse) is place a mark on the front side of the fuse formers at the bottom directly in the middle of the former. Placing a straight line on your work surface and matching the marks on the formers to the line will serve as a jig or guide to keep the fuse, front to back straight.

The fuse sides are parallel from F 1 to F 3. Glue these 3 formers at right angles to the fuse sides. At this time glue the short pieces ( 1/2" or less) of the yellow tubing in the slots provided in the formers. Doing this after you glue the formers is not good.

A nose block and tow hook is not furnished in the electric Mini Bird E, they are furnished in the Mini Bird thermal version kit.

Install the top and bottom rear longerons to both sides. Note the longerons butt against former F-3.

The longerons, as shown on the plans, are beveled at the rear to accommodate F 8. If you have a Perma Grit sander, you can create the bevel after former F 4 and 5 are installed.

Install the 1/8 " sq. spruce rail.

Set the fuse side with the three formers attached upright on the straight line and glue the three formers to the other fuse side.

Install the remaining 1/8" sq spruce rail.

Install formers F 4 and 5 with the small pieces of yellow push rod tubing.

Do not install the top and bottom before installing the push rods. Although the yellow tubing is furnished in the kit, I don't use it, but you have to keep the holes in the fuse formers open during the gluing process if the tubes are not used. I install the fuse top, but not the bottom before I install the push rods. The rear bottom is installed after the stab and elevator are glued to the fuse and hooked up to the push rods and the rc/ batteries, etc are installed. The front bottom is installed after the spacers are glued to the bottom of the hatch block and the blind nut wing mounting system is installed and the servo tray is installed. If you put the front bottom on before the blind nuts and spacers, you will be hard pressed to do it later. Not good.

I install the stab and fin with the elevators and rudder installed before the wing mounting system. The stab position will then be used to align the wing horizontally. The wing can be installed before the stab and fin.

Stab - Elevator

Pin the stab to the building surface.

Place the spruce tie bar and elevators against the stab and glue the tie bar to the elevators with wood glue.

Sand the outside edges round.

You have a choice of using the hinges provided in the kit or taping the elevator to the stab. If you use the hinges, bevel the front edge of the elevator as shown on the plan. If you use a tape hinge on top of the stab and elevator, bevel the front edge of the elevator to allow the elevator to move down without hitting the back edge of the stab.

Cover the stab and elevators before assembling the elevators to the stab. Leave the portion of the stab where the fin will touch uncovered for gluing purposes.

Fin - Rudder

Glue both F 10 to each side of the rudder as shown on the plan. Note the F 10 with the slot is on the left side of the rudder.

Sand the outside edges round.

Bevel the rudder for hinging as above.

Cover the fin before gluing to the rudder. Do not cover the rudder tabs that protrude into the stab slots.

Covering

Several choices here.

I finish my Lil' Bird 2 and Mini Bird E by using oil based Polyurethane applied with a good one inch brush. Oil base is used instead of water based because you know what water does to wood and especially 1/32" thin balsa wood. Water based polyurethane is used where foam is present in the construction of some models.

The secret to a light covering with polyurethane is Bounty Paper Towels. Apply the Poly to one section of the wing at a time and wipe off with Bounty Towels immediately. Don't let the Poly run inside the wing and fuse or soak into the wood. I wipe until I can see no sign of dampness. Bounty will suck up the Poly instantly, other brands of paper towels will simply push the poly around. One coat is plenty.

The same process is used on the remaining parts of the Mini Bird E.

Cover the open bays areas of the wing with a light plastic heat shrink. I use what I sell on my web site because it is the lightest weight and is very user friendly.

Depending on what type of surface you fly from (landings) you may want to cover the front bottom of the fuse for added protection.

The entire model or parts of it can be covered in your choice of light weight heat shrink plastic without the mess of Polyurethane. But remember, the wing's trailing edge and d - tube sheeting is 1/32" balsa wood and it won't take much for the heat shrink material to warp these fragile wood surfaces.

Final Assembly.

Install fuse former F 8 if you haven't done so already. Note it protrudes behind the fuse formers..look at the construction plan.

Use an Exacto blade to cut a slot in the elevator and rudder for the plywood control horns as shown on the plans. Make sure they align with the exit slots in the fuse sides.

Use epoxy to glue in the control horns.

Use an Exacto blade to make slits for the rudder and elevator hinges unless your hinges will be tape.

Glue the rudder to the stab, make sure it is straight up 90 degrees to the stab.

Slide the wire push rods onto the plywood control horns leaving the z bend in the horns.

Install the push rods through the fuse and glue the stab to the fuse. A trial fit is called for here to check stab alignment.

Install the two laser cut plywood blind nut bases under the 1/8" sq spruce rails.

Place the wing on the fuse and check for alignment to the stab and top view.

Drill through the holes you made previously in the wing's dihedral joint and into the two plywood blind nut bases.

Place the two nylon 4-40 bolts through the wing and the plywood basses into the blind nuts. Slightly tighten the bolts and seat the blind nuts.

When your satisfied with the wing alignment, use 5 minute epoxy to secure the blind nuts to the plywood bases. Not the nylon bolts.

Use your hand to move the push rods to make sure the controls work freely.

You can install the motor and four triangular balsa sticks surrounding the motor, the battery and controller, and rc equipment now, before installing the bottom of the fuse. The triangular sticks can be sanded to contour the nose to a prop spinner.

The battery hatch construction is self explanatory. Extra 4-40 nylon bolts are included for wing and battery hatch hold down.

Most builders today don't take the time and make the effort to read the construction plans before starting the construction. Most want to open the kit box and start building and reading the instructions simatanously. Real builders read the plans first, I hope you did.

Trimming and Flying.

Balance the model on the back edge of the spar. During first flights set the balance point on the front edge of the spar.

The up and down elevator movement is not critical. Usually, the pilot makes the difference. I like a lot of elevator and rudder travel to be able to keep the plane out of trouble when it is near the ground. If your a control stick banger, side to side, no finesse, up and down, nervous norvis type flyer than you can set the controls up to have less travel volume to smooth out your flights.

I leave the power system up to the builder. I'm using a Speed 280 direct drive with a 6 - 3 folding prop. The fuse interior has plenty of room for any type of battery configuration.

Enjoy.

Assembly: Attach the parachute to the line and then attach the chute to the reel. Wind the line on the reel and then add the rubber to the line. Continue winding until all the rubber is on the reel. The rubber ends up exposed to light, to extend the life of the rubber, always keep the Hi Start in a box.

Launching: Drive stake, attached to the metal ring on the end of the rubber, in ground, up wind of your launch and landing site. Walk down wind until line is off the reel. Hi Start can be stretched between 20 and 30 paces, place reel on the ground from your (stretched ) launching point for easy reference.

Launching Method: Remember the rubber is only 40 foot long and therefore you do not want to waist any of the stretch by simply letting go of your sailplane. Letting go means your plane will initially travel towards the stake without gaining much altitude. Figure it out, watch how much forward and nearly horizontal the plane travels before it starts to really climb out. If the forward travel distance is 20 feet, more or less, that is the amount of stretch in the rubber you removed before the plane starts to climb by simply letting go of the plane.

Ray's Launching Technique: We learned this method when I was living in the great state of Michigan during my Hand Launch Sailplane Mini Hi Start flying events called the Great Lakes R/C Soaring League. It works great on Ray's Hi Start for 2M, Std and light weight 3M planes.

A. Place the tow hook no further forward than the CG location. I found that putting the hook behind the CG and using down trim during launching will produce the highest launch, including zooming off at the top.

B. Use 20 to 30 paces depending on wind velocity and size of sailplane. The more wind the higher the zoom. Start with 20 paces on 2 meter planes. I launch my 100" Big Bird on no wind days from 30 paces and it releases directly over the stake.

C. At time of release, do not just let go of your sailplane, you are inviting a pop off, especially on 2 Meters. Try to throw your plane as straight up as you can, this means the plane will be headed up instead of out and close to flying speed when it leaves your hand. The result is the rubber will not lose much of it's stretch and provide the power to take the plane above the stake even on windless days.

One more launching tip, my body is between the plane and the stake when I throw the plane up. I am not behind the plane, extending my arm towards the stake while holding the plane, which would mean I would just simply be releasing the plane from this stance. Enjoy and don't forget to use a landing spot or tape every time you fly, Practice, Practice, Practice.

Ray Hayes

• If you don't plan on using the adhesive immediately after purchasing it, always store it in the refrigerator. When you take it out, let it warm up to room temperature before opening the bottle. Never store CA adhesives in direct sunlight. The UV rays from the sun will greatly shorten any CA's shelf life.
• Never store accelerator products near CA adhesives. Just the fumes from the accelerator can cause CAs ( Thin especially ) to begin to polymerize and thicken. This will shorten the shelf life of any CA product.
• Never double glue a joint that has just been accelerated. Again, the fumes from the accelerator will cause the adhesive in the bottle to start to polymerize.
• Once opened, always leave the cap off the bottle. The cap is not made of the special thermoplastic that the tip is made from and CA will stick to it.
• When a blob of CA forms across the end of the bottle tip, knock it off with the back edge of an X-Acto knife. For worse clogs, take a rag and hold it against the tip until the adhesive bonds on the rag. Hold the rag tightly against the tip and twist the bottle while pulling it back. The clog will almost always come off with the rag.
• Never stick a pin or anything else into the tip of a CA bottle to open it or remove a clog. This will introduce foreign material into the bottle and scratch the inside of the tip which will cause more clogging. It is better to replace the bottle top with a new one if this becomes a problem. Always open a bottle by cutting off the tip with an X-acto knife or single edge razor blade.
• Use accelerator sparingly and only when you need to.
• Never store open bottles in high humidity environments like a basement in the summer. All CAs are polymerized by trace amounts of moisture and high humidity conditions will greatly shorten the open bottle shelf life.

Sky Bench has been using Balsa USA and Sig Mfg. Inc. CA glues since they arrived on the market. They are both very good glues and we recommend them highly. The thin CA is the most widely used for balsa to balsa, balsa to spruce, balsa to plywood and plywood to spruce. We keep our stock in a freezer.

The Sky Bird is the largest of the Bird Series that started with the Lil bird 2 hand launch design. This Bird flies just like all my Bird Series, slow or fast with just a couple of clicks on the stab trim lever. It is capable of very tight turns to stay in small thermals without dropping a wing tip and because bigger flies better, the

Sky Bird will give you long flight times even in marginal thermal conditions. The design has produced a highly maneuverable sailplane that is extremely easy to fly and land.

I have yet to install the spoiler blades in my first Sky Bird. I usually come down from a high thermal flight by diving my planes down towards me and then burning off speed away from the landing spot. With a moderate long approach, the Sky Bird without spoilers will come in about a foot off the ground and be ready to land at the spot. My second Sky Bird will have wings with flaps with a coupling mode to the stab for precise landing control. The flaps will also open up the speed envelope and by dropping them approximately 1/16" provide increased thermaling ability in very weak lift.

Who will be the first person to build a Sky Bird full house, flaps and ailerons? The tip panels will need to be lowered and I am hoping to the first to have a full house Sky Bird. I started flying the Sky Bird with a wood fuse and now have it on a glass fuse that is truly good looking, very strong, and cuts the building time. You will not believe how quick the glass fuse Sky Bird builds up. Basically, you build the wings, and everything else is done. I know you will love flying my Sky Bird.

Watch for more new designs in the Bird Series. I am working on a 50 incher and a P-30 Class rubber free flight version of my great Lil Bird 2. Both could be used with electric power. I hope to be flying a 30" Micro Bird with electric power in my backyard soon and the free flight version at the AMA flying site this spring.

Ray Hayes

Sky Bench

Wing:

1. Pin down the pre cut inner wing panel trailing edge over plan and wax paper. Likely you will have to build the wing a panel at a time unless you have a very long building board.

2. Use Rib # 10 as a guide to locate the position of the front bottom sheeting, place the rib on the rear bottom trailing edge sheeting. The front spar notch in the rib will now determine precisely where to locate the back edge of the front bottom sheeting. Do not glue the rib at this time.

   .....NOTICE..... DO NOT TRIM OFF THE APPROX. 1/4" EXCESS OF BOTTOM SHEETING PROTRUDING IN FRONT OF THE WING RIBS AT THIS TIME.

3. Place a Mark on the bottom trailing edge and front sheeting for rib locations for ribs 2 through 7.

   Glue in the center sheeting between the bottom rear and front sheeting of the inner panel.

4. Check all the ribs to see if they fit over the spar and touch the bottom front sheeting. This is critical to having a smooth and accurate airfoil on the bottom of the wing. If the ribs are not touching, use a metal file to enlarge the rib notch.

   The reason they may not touch the bottom sheeting is the spruce spar maybe oversize and the additional thickness of the carbon application.

5. Glue in all the ribs with CA, starting at the trailing edge. Rib 1 is glued first using the plywood shearweb # W 4 as a guide to get the proper angle. Use 5-minute epoxy Or wood glue (only on rib 1). Hold the remaining ribs in place, apply CA and firmly hold each rib to the rear trailing edge bottom sheeting until the CA has cured. I prefer using wood glue in place of CA. Now glue only an inch or less of the rib, STARTING AT THE SPAR, to the bottom sheeting on the front side of the spar. Hold the rib down firmly enough to insure the sheeting is flush against the rib. The remaining front part of the rib will be glued to the front bottom sheeting later.

6. The bottom trailing edge sheeting requires sanding to a bevel matching the rib contour to create a thin trailing edge.

7. Use slow cure epoxy to glue in the 3/8" thick vertical balsa shear webs between the ribs on to the bottom spar. Do not glue in the shear webs in the last bay next to the polyhedral joint and the bays between rib 1 through rib 6. Before gluing, trial fit top spar to see that it is flush with top of ribs where top sheeting will be placed on top of spar. You want the top sheeting to blend smoothly with the top of the ribs.

   .....NOTICE..... THE SHORT TOP SPAR IS NOT GLUED IN AT THIS TIME TO ALLOW ACCESS TO THE FRONT BRASS WING JOINER TUBE.

   The top spar and 3/8" thick shear webs can be glued in one operation using slow cure epoxy. Use weights on top of the top spar and rear ribs/trailing edge. The flat portion of the wing from the spar rearward has to be kept flat on the building board to insure a straight wing instead of twisted. Apply the epoxy to the top of the shear webs and spar notches, set spar in place and apply weights. The epoxy really soaks into the 3/8" vertical grain balsa shear webs and could cause a lack of epoxy adhering to the bottom of the top spar. Clean up the epoxy that is squeezed out before curing takes place.

   .....NOTICE..... MAKE SURE TO CLEAN UP ANY EXCESS EPOXY BEFORE IT CURES, especially between the bottom front spar and rear short spar. THIS WILL INSURE AN EASY TIME OF GLUING IN THE PLYWOOD SHEAR WEBS # W 1, 2, 3, 4 TO THE SPAR EDGES.

8. To glue the front bottom sheeting to the bottom of the ribs, remove the wing from the plans/building board. Starting with the middle ribs, hold the sheeting tight to the bottom of rib #9 and glue with CA. Next glue the adjacent rib #10-16 in the same manner. Alternate the ribs to be glued from one side of rib # 9 to the other side. This is a very important method of applying the bottom wing sheeting to the bottom of the ribs. If you start gluing the sheeting to the root rib or polyhedral rib you will end up with buckled sheeting.

9. Use the Perma Grit sander to clean up any epoxy protruding from the edges of the top and bottom spars. It is critical to the strength of the wings to glue the plywood shear webs # W1, 2, 3 4, 4a directly to the edges of the spars and 3/8" vertical balsa shear webs. The Perma Grit sander F 100 sander can easily reach down between the short and long spars as well. If you have allowed epoxy to accumulate between the two bottom spars it may be necessary to cut through the bottom sheeting to clean this area out.

   .....NOTICE..... THE PLYWOOD SHEAR WEBS MUST FIT FLUSH AGAINST THE SPAR EDGES AND 3/8" BALSA VERTICAL SHEAR WEBS.

10. Use a metal file to lightly sand and roughen the brass wing joiner tubes. Insert only the FRONT brass tube into the ribs between the main spar and tack it in with CA.

    .....NOTICE..... THE BRASS TUBE MUST PROTRUDE OUTSIDE OF RIB 1 TO ENABLE THE TUBE TO EXTEND THROUGH THE PLYWOOD ROOT CAP WHEN IT IS INSTALLED LATER.

11. NOW YOU HAVE THE OPTION TO CONSTRUCT THE TIP PANEL OR CONTINUE WITH THE INNER PANEL BY GLUING IN THE PLYWOOD SHEAR WEB W1.

    If you construct the tip panel now, you will be able to speed up construction by gluing in the W1 plywood shear web to the inner panel spars and at the same time, prop up the outer panel and glue it to the inner panel along with the polyhedral plywood braces W5 and W5A. The inner panel will be as flat as your building board if it stays on the board until after the tip panel is glued in place.

    INSTALLING THE WI AND W2 PLYWOOD SHEAR WEBS.

    .....NOTICE..... The plywood shear webs are beveled on one end to set the angle on rib 1 to be flush with the side of the fuse.

    Block up the leading edge, under the front of the wing ribs. Use a Zona saw or equivalent to cut ribs 2 through 9. Use an F 100 Perma Grit sander to sand the rib enough to allow space for the shear web. Glue shear webs W 1 and W2 together before installing in the wing. Use slow cure epoxy to install W 1 and w 2 applied to the edges of the spars and the entire surface of the vertical 3/8-balsa shear webs. Also apply the epoxy to the side of W1. Place the W 1 and W 2 against the spars and clamp. Clean up the excess epoxy after the clamps have squeezed it out.

    Cut the ribs 2 through 6 on the backside of the front spar, use the same procedure of the W1 and W2. Fill the spaces around the front brass tube with a mixture of epoxy and Micro Balloons and slide W3 in place and clamp.

    The rear top spar is supplied longer than shown on the plan to reach rib 11. Glue it in and the second brass tube. Cut spar notches in ribs 8 through 10 to accommodate the longer top spar.

    Glue W4 and W4A together. Cut ribs 2 through 6 as above. Fill in the spaces around the rear tube with a mixture of epoxy and micro balloons and glue W4 and W4A in place.

    Glue in the 1/8 plywood wing hook base to rib #1

    Glue in the rear alignment aluminum tube and 1/16 balsa.

    .....NOTICE..... The inner panels of both wings have to be set up on a flat surface with the wing rod inserted before gluing in the brass tubes and rear alignment tube in the other wing.

    .....NOTICE..... Before you place the sheeting on top of the ribs, decide how you are going to power the spoiler blades. The plans show a servo for each spoiler, so don’t forget to make accommodations for the servo wire to run through the wing ribs.

12. The tip panel is constructed in the same sequence as the inner panel.

    .....NOTICE..... DO NOT GLUE IN THE POLYHEDRAL RIB #16A AT THIS TIME. IT IS GLUED IN AFTER THE WING TIP IS JOINED TO THE INNER PANEL.

    Weights will be necessary on the top spar to hold it in place due to the height of ribs 18,19,20 while the wood glue is curing. Glue in all the shear webs except in the bay between the polyhedral rib # 16 and rib # 17. The tip block and top wing sheeting are applied after the tip panel is attached to the inner panel.

    After the inner and tip panels are joined, don’t forget rib 16A, install the rear trailing edge sheeting to the inner panel. Install the inner panel front top sheeting. Remove the wing from the board and lay the tip panel flat on the board to install the front and rear top sheeting.

    Install the spoiler frame and the plywood spoiler horn.

    Sand the sheeting flush with the front of the ribs and glue on the leading edge using masking tape to hold it in place till the wood glue sets up.

    Glue the wing tips on.

    Sand the leading edge. Block sand it initially, draw a straight line at the entry point of the airfoil on the leading edge and use the line as a reference to finish sanding.

    Cover the wing with your choice of heat shrink covering.

13. Fiber Glass Fuse:

    Install the tow hook base with epoxy. Center the base with the first wing joiner location.

    Install the two brass tubes and rear alignment tube in the fuse, but do not epoxy until you have verified alignment.

    Place the wings and stab on the fuse for a trial fit to verify alignment. Stab must be level to the wing.

    If alignment of wing and stab is good, epoxy the tubes in the fuse.

    Place wings and stab on fuse and verify stab alignment. If it checks out ok, epoxy 1/64^th plywood stab base to the fuse. Use the stab to check and recheck alignment while curing

    Install the servo tray on top of the spruce rails with epoxy. Some slight adjustment to the servo tray may have to be made.

    Drill holes for servo mounting in the tray.

    Install canopy formers with silicone glue

    Paint fuse. Pay attention to weight added to rear of fuse.

    Install push rods, servos and switch.

    Construct elevators and hinge system of your choice, tape on top which will require beveling the front edge of the elevator for up and down movement, or use the hinges supplied in kit which require sanding bevels above and below the hinge center line in the elevator. Sand outside edges round. Sanding a taper in the elevator will add flight performance.

    Do the same for the fin and rudder.

    .....NOTICE..... THE ELEVATOR HAS TO BE INSTALLED TO THE STAB BEFORE INSTALLING THE RUDDER TO THE FIN. BEEN THERE, DONE THAT, IT IS BAD FEELING, BUT CURABLE.

    The stab/elevator and fin/rudder are covered before the stab is glued to the fuse and the rudder is glued to the fin. Don’t cover the gluing areas. Glue the stab with slow cure epoxy or wood glue to the plywood stab base.

    Install the push rods, control horns and RC. Install the hooks for the rubber band canopy hold down system, one epoxied to the roof of the canopy the other screwed into the plywood servo tray. I taped mine on one side to make a hinge.

    Balance the Sky Bird on the back edge of the spar with shot gun pellets mixed with epoxy. You do this after you determine how much weight is required to balance and then weigh the pellets out before mixing in the epoxy.

    Install the tow hook by drilling a hole beneath the front edge of the first wing joiner rod.

• 1/32 balsa wood front fuse sides to be glued to the outside of the forward plywood fuse sides.
• Two 1/8 x 3/8 spruce sticks to be placed on inside of fuse sides below the canopy.
• Two 1/8 laser cut rectangles to be placed on the inside of fuse under the laser cut servo tray.
• Two wing joiner brass tubes instead of one.
• Three canopy spacers glued to the bottom of the hatch block instead of two.

Start construction by:

Glue the 1/32 laser cut forward balsa sides to the 1/8 " plywood forward fuse sides. Do not use water based glue.

Glue the forward and aft fuse side parts together, use a 36 inch ruler to make sure the bottom of the fuse is straight.

Glue the forward and aft 1/64 laser cut plywood doublers to the inside of each fuse side. apply slow cure epoxy to the 1/64 plywood.

Cut and angle the 1/8 x 3/8 spruce rails and glue to the fuse sides, use F2 as a locating guide. use slow cure epoxy.

Make a mark on the face of each fuse former at the bottom that is accurately in the center of each former.

Assemble the fuse formers to the fuse sides directly over the center line on the construction plan. line up the mark on the formers with the center line on the top view of the fuse plans.

Glue formers F 2, F3 and F4 to the fuse sides first. use slow cure epoxy and clamp. If you get this accurate, you will have a straight fuse. make sure you keep the push rod holes open in the fuse formers.

Glue formers F1 next followed by F5 and F6 and then F8 (stab mount).

Glue F9 after sanding to fit (balsa block).

Glue the nose block in place.

Cut/sand the canopy balsa block to fit and glue on the canopy block spacers to the bottom of the block by placing the spacers inside the fuse sides and placing the block on the spacers. Check spacer alignment by viewing from the bottom of the fuse.

Glue the two 1/8" rectangular plywood laser cut servo tray supports to the inside of the fuse.

Install the servo tray and the RC on and off switch.

Install an antenna tube from F 2 through F 6. I use a series of straws because they are virtually weightless.

Assemble the wire push rods using the couplers and solder, install them in the fuse.

Glue the rear laser cut balsa top inside the fuse sides.

Glue the forward laser cut plywood bottom.

Install the tow hook base and hardwood mount.

When the wing is completed, install the two brass wing joiner tubes and aluminum alignment tube in the fuse, but do not glue them in until you have assembled the wings to the fuse and checked for alignment to the fuse, to the stab and equal angle of incedence of both wings. Glue the tubes in with epoxy. The alignment should happen automatically if the fuse is built properly, but we are just humans, so check your work before gluing the tubes and stab to the fuse.

I drill a few 3/16" holes in the plywood stab mount before gluing the stab to the fuse with slow cure epoxy. The holes will improve the glue joint. I also cover the stab before gluing it to the fuse as well as the fin before gluing it to the stab, be sure to leave the gluing areas uncovered.

Install the balsa blocks above the wing joiner tubes and the rear bottom of the fuse.

Sand the fuse corners, nose block area and canopy. I use a Perma Grit sander becuase they sand so much quicker than sand paper on blocks. Why are they quicker, because they don't load up.

by Bruce Ettinger

Power considerations: The final weight of the electric powered (ep) Sky Bird will be about 5 1/2 pounds. A minimum of 50 watts per pound is needed and 75 watts allows better climb and ROG (see carriage). To provide 250-300 watts, use a Phasor 30-3 or equivalent, with 12/6 folding prop (Graupner). A 3-cell lipo battery with 3400-37000mAh capacity allows lots of flying time.

Weight considerations: The power train consists of Phasor 30 (7.7oz), Jeti 40 speed controller (1.3oz), prop/spinner/adapter (1.7oz), and 3700 3-cell lipo (10.4oz). This totals 21oz. A comparable Outrunner brushless motor would be 28-12; this motor, like the Phasor, has a 32mm outside diameter. By replacing the receiver battery (3oz) and avoiding lead ballast in the nose, the overall weight is increased by about 16 ounces. Given the 9.3 square foot wing area, the added weight increases the wing loading from 7.5 to 9.2 ounces/square foot. We used one steel wing rod and one carbon fiber rod (probably one rod would do for electric power). Depending on the size of the battery, some lead will be required in the tail---about 1 or 2 ounces.

Fuselage changes: To accommodate the Phasor 30, the front of the fuselage needs to be expanded in width. Make 2 new formers (replace #1 and make new firewall). These need to measure 40mm (inside) in width, not including notch extensions. Make the hole in #1 large enough to accommodate the 3 large wires and connectors from the motor to the speed controller. The 40mm inside width will allow enough room to fit a 32mm wide motor (see thrust below for explanation). The bottom plywood sheeting also has to be replaced with a wider version to accommodate the wider front-and this should have four 3/4 inch cooling holes starting about 6 inches back from the front (leave 1/2 to 3/4 inch between holes)-these will help cool the battery. When carving the main hatch cover, create a good-sized air intake duct towards the front-this will allow air flow over the motor and back to the battery. Both 2 over-wing blocks need to be made into removable hatches to allow access to the servos as well as the wing-holding spring. Instead of installing a tow hook at the CG, set a nylon washer over the drilled hole- this will allow use of a launching hold-down pin.

Placement of battery: The lipo battery will fit nicely in front of the wing in the main hatch area. By keeping battery close to the motor and speed controller, you avoid long, heavy wires trailing through the fuselage. This means moving the 2 servos and radio to the under wing area.

Thrust: Having electrified several sailplanes, I knew that at least 4-5 degrees of down thrust was be needed---otherwise you will be applying a lot of down elevator and the transition from power to glide will not be smooth (even with channel mixing). Rather than making the firewall (engine mount) at right angles to the lower fuselage line and parallel to other formers, tilt it downward about 3/32 inch. This also avoids an unaesthetic tilting of the entire motor and prop assembly (making the spinner far away from the nose on top but close on bottom). Two or three degrees of right thrust will also be needed (accomplished by placing a washer between motor and firewall on the right upper mounting screw. The motor will be angled inside the fuse front, and this requires the extra room we have built in (40mm for 32 mm motor cylinder).

Flying: In a word, spectacular! The climb rate was fine at half-throttle. Using transparent Monocoat allows the sun to glow through the 11 foot span beautifully. The glide rate is a bit faster than "floating" and landings are possible without spoilers, although lots of space is needed. I would suggest spoilers if landing space is limited.

Congratulations: The Sky Bird is awesome in size and behavior. I hope he produces an "ep" kit.

Thank you very much Bruce, I'll create a modification kit for electric power with a slightly different approach to the cooling system and shape to allow the use of a prop spinner. Ray

Skybench modification instructions

Stab fairing photos

This is the stab fairing block that fits inside the fin. I start by cutting the block at the same angle as the rear fin post and then making a hole from top to bottom for the block to slide down the front fin post. Mark the side of the block as shown using the plywood fairing side piece and make the necessary cut outs for the front fin post and control horn. Drill a hole for the aluminum pivot tube that the stab control horn pivots on. The front of the block has a point due to the sweep in the leading edge of the stab. After mounting the stab, use the stab's LE to finish off the front of the fairing block to match the angle of the stab's leading edge.

Notice: The stab control horn has to be installed and the push rod connected for a trial fit before gluing the block in place and putting the sheeting on the sides of the fin. Included in the trial fit is making sure the stab is straight and level with the fuse and wings. When all of the above is finished then sand the fairing block to it's final shape.

The left side sheeting added to fin frame work. Notice the 1/64 plywood rectangle at the rudder push rod exit hole. This adds durability and helps eliminate sloppiness. The metal clamps are women's hair clamps available from K- Mart, etc. They are easily shaped to fit any circumstance. Very handy.

Fuse photo:

This is my second fuse due to RC radio failure. I am trying to give it a very old look (Miss America for those that know) and have placed 1/64" plywood on the outside and inside of the fuse.

Top hatch photo:

I used a top hatch in my first Challenger to have access to the spoiler servo located in the fuse between the wings and it also makes the hook up of the flap servos located in the wings convienent. Note the ballast compartment with the door removed. Nylon 4-40 bolts and blind nuts are used to secure the ballast door and top hatch. The top of the fuse and hatch lid will also have 1/64" Plywood.

1. Big Bird will zoom launch very well.  Without ballast, it will keep up with most composite ships.  Add a 12 oz. slug of ballast lead (just a bit behind the C.G. enough to relocate the C. G. rearward about an 1/8")  and it will stay with all comers on the launch.  If you plan on zoom launching, it would be advisable to add additional 1/16" plywood shear webs to the sides of W-1 and W-2.  Add from rib #1 to rib #3 for added security.
2. Big Bird will turn very tight and therefore utilize small thermals to speck out.  The airfoil is not prone to tip stalling and therefore allows the C.G. to be located rearward which helps produce very tight turns.  The rearward C. G. also means the wing will fly at a smaller angle of attach and thus be able to fly faster when down-trim is applied to return to the flying field after a long down wind flight.
3. I fly my Big Bird with the C.G. located 5-5/8" forward of the wing's trailing edge, and the tow hook is located 5-3/8" forward of the T.E. (1/4" behind C.G.).  To accommodate this C.G. set-up, the rudder throw is 1-1/4" L.-R. and the elevator is 3/4" up and 3/8" down.
4. I have an ELECTRIC powered Big Bird and it has a very flat glide. In fact, it is awesome!  Ask Jack Hamilton of Texas how well the Big Bird flies as an electric.  Included in the kit is a diagram from Jack showing how to set the Big Bird up for LMR competition and the plans show a geared Master Air Screw installation.  The standard steel Dave Squires wing join rod that comes with the kit is exchangeable for a light weight carbon rod at no extra cost.

There are two benefits received from building model airplanes without washout in the wings.

1. The wings provide more useable lift using the same airfoil if the entire wing is flying at the same incidence.
2. The wing can be built more accurately. This is critical to the flight performance of any design.

Washout in wing panels is used to delay tip stall, and therefore make the model easier to fly, but at a lower flight performance.

Please do not build the above designs with washout in the wings.

Most beginners to r/c models are advised by someone to be sure and have the c.g. (center of gravity), or balance point, set forward so the airplane won't be squirrelly. I have heard this on flying fields since 1968. Because of this poor advice, most r/c sailplane pilots' skill levels at finding thermals remains mediocre.

The results of a forward balance are:

1. The r/c sailplane plows through light lift conditions without indicating the lift to the pilot. Flying r/c sailplanes is all about observation.

    

2. The ability of a sailplane to make flat turns is reduced. A well balanced model requires very little elevator control movement when circling in lift.

    

3. A sailplane with a forward c. g. will not climb well, if at all, in light lift conditions.

1. The model will indicate lift conditions by doing something different while flying. The nose may come up abruptly, the wings may rock or wiggle, or the sailplane may change its course.. All this movement of the sailplane is what the poor advice is trying to eliminate. Most pilots don't realize that the movement is caused by rising thermals.

    

2. When the glider in flight does something different, as described above, you should immediately turn the model and perform a full circle. More than likely, it will go up. My designs will allow the glider to turn on a dime and this will keep the glider in the thermal.

Remember, the thermal is being pushed downwind by the wind, so let the glider go downwind with the thermal to gain more height. All my designs penetrate at light wing loadings and therefore, even the Lil Bird 2 will fly safely in 15-20 mph. winds without adding ballast.

1. The plans of the fuse side view and top view of the stabilizer show the 1/8 x 3/16 balsa longerons ending at the rear edge of the fuse. This requires the ends of the longerons to be tapered as shown in the top view of the stab. This provides a fairly wide base for the stab to attach to and will help provide a straight fuse.

    

2. To narrow the fuse (reduce the width of the fuse formers) the longerons will end at the front edge of f-6 and require tapering 1/16 off each longeron in front of f-6 for a short distance. Add 3/8 wide, .007 carbon laminate with ca to the inside of the fuse sides at this juncture for required strength.

Why narrow the fuse?

1. To maximize the LB2 flight performance. Narrowing the fuse will reduce the frontal profile drag created by the fuse. Besides narrowing the fuse formers, a ¼ inch can be removed from the bottom of the fuse at the front, tapering back to the original depth of the fuse at the rear.
   
2. To improve airflow at the fuse/wing junction, lower the top profile of the hatch block so that it meets the wing's leading edge.

Please do not cover any parts of LB2, other than the open sections of the wing. Do not wrap covering around the wings' trailing edges.

To install the brass wing joiner tube, first roughen it up with a file to improve epoxy adhesion. Slide the tube over the wing joiner rod and then install in the fuse.  Slide both wing panels on to the joiner rod, check alignment, and apply small amounts of 5 minute epoxy around the tube inside where it touches the fuse.  Just enough to secure it. Let the epoxy set up fully before sliding the wing panels off the joiner rod.  Apply additional epoxy to one end of the brass tube at a time inside the fuse for additional strength. To prevent the sides of the fuse from becoming scratched while filing off the protruding ends of the brass tube, cut a hole in masking tape and slip over the brass tube and apply to the fuse sides.

The plywood R/C and electric motor battery tray is shaped perfectly, and so are the two formers. To remove the die cut parts, simply sand the back side of the plywood until the part is easily removed.

If you install an electric motor, two plywood motor mounts are furnished. Use only one to clear prop connector.

The plywood R/C tray sits low in the fuse, so the servos are best mounted by using a cross rail on top of the tray. The ACE 8107 servos ($17.95 from Sky Bench Aerotech) get lost in the huge, but strong , servo tray. I am using a 500 motor, ACE six cell 1800 Mah battery and a 10 - 6 Graupner folding prop.  The Graupner 8 - 6 spinner/folding prop combination fits the fuse profile perfectly, but I altered the 10 - 6 prop to fit the smaller spinner to increase the thrust performance.

The control cables have pre-installed, threaded, connectors for the clevises to attach to at the control horn junction, and the screw-down type connectors quickly anchor the cables to the servos.

The Palio can be assembled in a long evening or in one day for sure. Therefore, the first step in assembly is to put the batteries on charge.

Photo #1: Vertical grain balsa blocks between the spars at ribs # 1 have been added to strengthen the dihedral joint. The blocks are also necessary because of the hole that will be drilled for the 4-40 one inch nylon wing hold down bolt. A 1/32 plywood dihedral brace will be added to the rear of the spar. Add similar blocks to the polyhedral joints. I have found using a Teflon tube in the CA glue bottle is very helpful. Apply rubber cement or contact glue around the tube where it exits the bottle to stop leakage.

Photo #2: Ray’s hinged wing construction fixture. This building system dates back to the 1930’s and was used to build free flight wings fast and accurate. Experimenting with poly angles is very easy. Note the plastic bags filled with shot gun pellets, they make very handy weights that are so necessary to hold the wing flat to the building board. Tools from L to R, Zona saw has a very thin blade and is used to cut through the poly joint ribs to add the plywood braces. After cutting the rib I use the small strip of Perma Grit sander to enlarge the gap to receive the plywood braces. The larger sander is an F-100 Perma Grit sander that easily and accurately sands the bevel in the trailing edge bottom sheeting. Quick cure epoxy never gets brittle like long cure epoxy does, therefore I use it to glue the spar and leading edge butt joints and dihedral sheeting joints. Notice the metal clamps in use to hold the plywood dihedral braces while the Sig Bond glue is curing. The clamps are women’s metal hair clamps available from K-Mart. They are easily bendable to any shape to accommodate small or large widths. All the tools and glue are available from Sky Bench Aerotech including the safety razor blades.

Photo #3: Leading edge of wing during the gluing process is held tight to the sheeting and ribs with masking tape.

Photo #4: The black line in the leading edge is .007 laminated carbon fiber. If you want to have a very strong , but light weight leading edge to help avoid dents and brakes here is how I build my LE. First glue on a 1/16” balsa stick to the sheeting and ribs as pictured in photo #3 and when the Sig Bond glue has dried sand the strips to the contour of the sheeting. Then use thin CA glue to apply the .007 laminated carbon to the face of the 1/16” thick balsa strip. Next glue on another 1/16” balsa stick to the carbon with CA and sand the edges to the contour of the sheeting and the first 1/16 strip. Glue on a 1/16” spruce stick to the 1/16” balsa strip and sand to the contour of the LE shown in the plan side view of the wing mounted to the fuse. A blunt leading edge is better than a to sharp leading edge.

Photo #5: Thanks to an accurately CAD drawn plan, the holes in the fuse formers to mount the boom are dead on accurate and coupled with the tab/slot fuse construction means the wing / stab incidence will be automatically attained. Experience has taught me that a kit with a nose block butt glued to the front former and/or the ends of the front fuse sides is a nose block that will break off easily. All my wood kit designs have the nose block sandwiched between the fuse sides for maximum strength and durability. Also note, that I have tapered the nose block, use the width of the flight battery pack as a guide.

Photo #6: This is how I glued my v-tail together. First cut it in half, then sand the proper angle and glue with short cure epoxy. The very tips of the stab are raised 4 ¾” from the work board. Make sure your blocks are parallel to each other and the v-joint is located centrally between the blocks. Apply 3/4oz. fiberglass tape to the v joint top and bottom with CA glue.

Photo #7: The construction plan shows a simple way to attach the v-tail to the bottom of the fuse. This photo shows how to make a completely drag free attachment. The next step is using CA to glue down ¾ oz. fiberglass tape over the glue joint top and bottom and then bevel a 1/16” thick spruce stick to fit inside the v joint and glue with slow cure epoxy. Drill two holes as shown to exit the yellow control cable housings. Drill them at an angle to prevent the cables or wire push rods from binding. Check for binding before you attach this assembly to the boom. Install the yellow cable housings in the holes and use slow cure epoxy to glue the stab to the inside of the stab notch in the boom. Use the glue sparingly. Drill undersized holes through the bottom of the stab and 1/16” spruce using the boom stab mounting holes as a guide and screw in the white 4-40 nylon bolts. Trim off the bolts as necessary.

Photo #1:
Photo #2:
Photo #3:
Photo #4:

The initial frame was extended a couple of inches to lengthen the tail moment. The kit has 1/64 plywood doublers located on the inside of the fuse frame and 1/4" sheet is used to fill the frame members starting just behind the wings trailing edge location. A piece of 3/32 plywood doubler is located inside the fuse on both sides approximately 2" outside the two wing joiner holes that extend from the top of the fuse to the bottom longeron. 3/32 plywood formers were made and glued in-between the 3.32 doublers. This will make the fuse in the wing joiner area adequately strong for modern day winch launching.

1/8 x 1/2 plywood strips are glued inside the fuse 1/8" below the hatch longeron and a 1/8 plywood servo tray is glued on top of the plywood strips. The strips extend from nose block to 2" behind the rear hatch opening. Additional 1/4 sq spruce longerons were glued inside the fuse on the bottom from nose block rearward past the hatch opening.

1/16" balsa was glued cross grain to the top and bottom longerons from front to rear except the bottom of the fuse from nose block to behind the rear wing joiner received 1/8" plywood. An additional balsa block will be glued to the bottom plywood and contoured sanded to make a rounded shape to the front of the fuse.

I built one stab half according to plan, but have decided to scrap it in favor of a stronger and easier stab/elevator.

Photo #5:

1/8 plywood piece not shown on plans. Attach to the bottom of the fuse after the fuse is framed up and the nose block is installed. The part is shaped to extend below the nose block for added strength.

Consequently, I have my 2m Lil Bird set up with the tow hook behind the CG, just like my Big Bird and 2M Osprey. This location requires a bit of down trim on the elevator when launching to produce a fast launch speed and end with an impressive zoom. My 2M Lil Bird weighs 22.5 oz. ( wing loading is 5 oz. per sq. ft.) and balances with out nose weight with micro servos and Hitec micro 555 Rx and a 700 mah flight battery. An alternative is a 270 mah battery with large servos and large RX. I did not install spoilers on this one piece wing version.

My set up specifications: Cg: 5 1/4" forward of trailing edge, Tow hook: 5 3/16" forward of trailing edge, Rudder throw: 2 1/2" L-R, Stab throw: 1/2" up/down.

2 piece wing; brass tubes are located in each inner wing panel as shown. To install the tubes, cut the front (longest) 1/16" plywood spar braces, WDBF, in half and glue to front edges of spars and vertical 3/8" balsa shear webs, prop up each inner panel at rib 7A (dihedral joint) 1 1/2", place the tubes with the joiner rod in place in the panels, space the root of each inner panel 1/4" apart and make sure the panels are straight and not tilted forward or rearward, make sure the joiner system is level and flush against WDBF, tack glue with 5 minute epoxy. Do the same with a 1/16" wire and aluminum tubes to make a rear alignment pin system. The brass and aluminum tubes must protrude through the furnished 1/16" plywood root caps for necessary strength. The cavity surrounding the brass tube is filled with a mixture of epoxy and micro balloons before the 1/16 Plywood brace, WDBR, is glued to the rear of the spars.

The one piece wing with the pictured laser cut plywood dihedral joiners is very strong and will take the most aggressive electric winch zoom launch.

The polyhedral joint plywood brace part is glued to the inner panel before gluing the tip panel.  Sand the bevel in the trailing edges before gluing the panels together. You can save a lot of time when sanding if you use a Perma Grit sander, see "Sanders" catalog for a photo of the sanders. 

Join the tip panels before joining the inner panels.  After the plywood polyhedral brace is glued on and dried, install 1/4" wide vertical balsa shear webs between the tip panel spars as shown on the plans.  At the same time, glue on the vertical shear web to the outside of the tip panel spars and clamp.  This produces a light-weight and strong polyhedral joint

Why is a Sky Bench wing so strong? I use 1/8x3/8" spruce spars in the inner panel and most important are the 3/8" wide vertical grain balsa shear webs between the top and bottom spar. The next photo will show the remaining step to make the center dihedral super strong.  Note the vertical grain shear web at the end of the inner panel, a corresponding shear web is located in the outer tip panel after the tip is glued to the inner panel.

The lead weights are important to building a strong and straight wing.  Notice the trailing edge is still pinned to the building board, and the bottom sheeting from the spar forward is not glued to the ribs yet.

Cut the wing ribs from the spar with a zona saw and then use a Perma Grit sander to enlarge the cut to allow the 1/16" plywood wing joiner to fit flat against the spars.  Take your time and prefit the parts before gluing.  The spar ends and bottom sheeting should fit tightly, making sure the wing is straight and not bent forward or backwards.  If you plan to zoom launch from an electric winch, add 1/16" joiner braces to both sides between ribs # 2.  Use the supplied laser cut braces as patterns.

Another view of joining the inner panels.  Notice the wings are weighted down to insure the wings are built flat instead of with a twist. Nothing turns a great sailplane into a dog quicker than a wing that is twisted at the center dihedral joint.  A twisted wing requires the rudder to be offset during flight.  During slow flight the twisted wing will cause the sailplane to turn one direction and during fast flight it will turn the opposite direction.  Take your time, check the alignments before gluing.

There are at least two ways to apply the top sheeting to the ribs and spar, but in each method, it is paramount to have the trailing edge pinned to the work surface and the ribs between the spar and trailing edge weighted down to keep the wing flat.  I prefer to have strips of tape attached to the bottom wing sheeting under each rib and use them to hold down the front edge of the top sheeting.  Before applying the top sheeting sand the excess bottom sheeting back to the front edge of the ribs and then apply the strips of tape.  Trial fit the top sheeting and cut the front edge back to the ribs before gluing.  Use wood glue to apply the top sheeting to the ribs and spar. Position a piece of balsa on top of the top sheeting above the spar and ribs to distribute the weights pressure.

Laser cut rudder and fin parts package. Note, since this photo, the fin and stab have been revised to insure a perfect alignment occurs during construction by adding tabs to the fin and corresponding slots to the stab.  This revision was also made to the Lil Bird 2 and Big Bird.

The kit has been revised to include tabs on the bottom of the fin that correspond to slots in the stabilizer.  This system automatically aligns the fin, but the triangle is needed to insure the 90 degree vertical angle.

The Bird Series kits are now highly prefabricated and include laser cut push rod slots in the fuse sides.  There is a LEFT and RIGHT fuse side because of the location of the slots.  The pushrods cross each other to make a smoother transition to the nylon control horns furnished in the kit.  On this model, a tube was used to insure separation of the two wire push rods.  A small coffee straw works well and is very light weight.  Attach the elevator to the stab before attaching the rudder to the fin.

Just below the stab is a 1/8 lite ply part that has the tab/slot feature. This functions as a fuse alignment jig and insures the glue joint between the fuse and stab is very strong.

The kit was revised to include pre laser cut holes for the nylon control horn bolts in the rudder and elevator.  The fuse is extremely easy to build and build straight.

The fuse parts are totally laser cut and feature tab slot construction. Notice the 1/64 plywood doubler has holes for the rubber band wing hold down dowels, but the balsa fuse sides do not.  This means if you decide to build the wing as a bolt on wing (wood parts furnished) the fuse will not have unsightly holes in the sides.  Wire pushrods with z-bends are furnished.  The fuse builds extremely quick and accurate.

The 2m Lil Bird fuse is very strong because: the nose block is sandwiched between the fuse sides, the fuse sides are partially laminated to 1/64" plywood, and the 3/16" sq. spruce wing saddle rails are secured by notches in the fuse formers.  Nose blocks glued to a front former rather than sandwiched between the fuse sides break off.

This is the part that is vital to fuse alignment, a strong fuse and a strong glue joint between the stab and fuse.  Install the bottom fuse parts last after the hatch block spacers are glued to the hatch and the pushrods are installed.

The aluminum foil will help prevent the fuse sides from the heat of the soldering iron.

A laser cut 1/8" plywood servo and on/off switch mounting part is now furnished in all of the Bird series and Osprey 1 kits.   This should help the builder immensely when installing the servos.  See "Viewer Photos" for customer comments on the 2M Lil Bird.

SUNBIRD STAB CONSTRUCTION

Construction of the SUNBIRD is simple. This is a photo of the proto-type kit laser-cut stab and elevator. The rear slot location in the stab has been moved forward in the kit version. Also, one extra stick rib has been added to each side of the stab in this photo. Sand the leading edge to a 1/8" radius and taper the elevator to 1/32" at the trailing edge. If you use tape for the elevator hinge, bevel the front edge of the elevator as shown on the plans for clearance. The laser cut hole in the elevator accommodates the pushrod control linkage. Cover with heat shrink Mylar and double check for twists.

SUNBIRD FIN & RUDDER CONSTRUCTION

The fin has four laser cut balsa wood parts plus the front fairing. One fin side has not been installed in this photo for clarity. Note the two tabs at the top of the fin. They correspond with the slots in the stab to help create a stronger joint. The very top of the yellow push-rod housing is not glued to the fin to allow some movement during activating the elevator. 

After the fin is completely assembled, glue the furnished spruce sticks to the leading and trailing edge of the fin for strength. The front edge of the rudder is beveled when using tape for a hinge. The 1/64" plywood doublers are glued to the rudder to support the rudder horn which is attached to the left side of the rudder . After the doublers are attached, remove the balsa wood to make a slot for the rudder horn and use 5 minute epoxy sparingly to glue in the rudder horn. Sand the rudder's edge to a 1/8" radius.

SUNBIRD FUSELAGE

All the fuse parts except the four longerons, two spruce rails, hatch and nose block are laser cut. The bottom front piece is rectangular in the kit rather than narrowed at the front as shown here. Not shown in this photo are two carbon laminate strips glued to the fuse sides to reinforce the rear of the fuse at the fin mounting location. 

The kit's LEFT rear fuse side has a slot for the rudder push wire exit. The longerons, 1'64 plywood doubler, fuse side halves, one of two spruce rails and F-2 and F-3 formers have been glued together in this photo. The formers have tabs that correspond to the slots in the fuse sides, this system provides building speed, strength and accuracy. 

NOTE: the two wing mounting plates (F4 and F5) are not identical and must be located correctly to match the wing bolt locations. A plywood servo and switch tray is provide for the builder's convenience and added fuse strength. REMEMBER TO INSTALL the wire rudder push rod, glue the spacers to the hatch, and install the wing mounting blind nuts in F4 and F5 BEFORE gluing in the two bottom pieces.

SUNBIRD WING CONSTRUCTION

The first stage of wing construction. The bottom front sheeting has not been glued to the bottom of the ribs from the spar forward. Note rib 1 (center dihedral rib) has not been installed. It is glued in when joining the wing halves. The clamps are holding the spar shear webs while the glue is curing.

Joining the polyhedral joint. The 1/64" plywood brace is glued and clamped. Note the white weights on the inner panel. The wing must be flat on the building surface to eliminate building a twisted wing. Pictured is a "Zona" saw with a wooden handle. This is used to cut the polyhedral rib when installing the 1/64" plywood brace and the center dihedral braces as well.

Gluing the top sheeting to the ribs. The top, front, and rear sheeting is glued to the ribs with wood glue. There are two ways to attach the front top sheeting to the ribs to avoid buckling the sheeting. Pictured are plastic bags partially filled with bird shot, a thin cardboard (cereal box) strip is under the bags to prevent the 1/32 sheeting from sagging between the ribs. The sheeting is pinned down at the front of the ribs into the work surface. Note the weights pressing the wing flat to the work surface to prevent building a twisted wing.

Pierce 970 Sky Bench Modifications

Changes from original kit plan. March, 2004

Laser cut parts: Fuse

1. Added 1/64 ply doublers to inside of fuse sides fore and aft.
2. Changed fuse side profile at wing joiner area for greater strength allowing the top balsa block to fit between the fuse formers.
3. Added 1/64 ply doublers to fuse former F 4 and increased the height for added strength.
4. Lengthened the front fuse sides to sandwich the bass wood nose block.
5. Changed the formers and fuse sides to tab and slot design.
6. Laser cut top and bottom fuse parts.
7. Fuse sides have one wing joiner and alignment hole instead of two.
8. Two 1/16" plywood wing fairing ribs to glue on sides of fuse.

Wing

1. Ribs do not require cap strips, Hooray for laser cutting.
2. Rib # 1 and 2 have wing joiner holes for one wing rod and alignment wire. If builder wants to use two wing rods ( not furnished )as shown on the plans , cut holes in ribs accordingly.
3. Ribs are oversized at rear approximately 1/16" due to tolerances discovered in 5/16 x 1-1/4" trailing edge stock. This is tricky so pay attention: if the TE pieces in your kit do not match perfectly to the rear edge of ribs W2, you have a choice of trimming the end of the ribs or notching the TE to receive the ribs, or cutting the front edge of the TE back about a 1/16". I dislike notched TE so I will opt for trimming the front edge of the TE stock. Folks without a proper saw may find it much easier to trim the ribs or notch the TE if necessary. You don't want the TE sticking up above the ribs, this will be ugly when covered and drastically have a negative effect on the airfoil.
4. Ribs on the inner panel are cut for 1/8 x 1/2" spars. Spar width is very important to spar strength.
5. Two 1/16" plywood root caps, make sure brass wing tubes pass through plywood root cap.

Stab

1. Thanks again to laser cutting, this stab is awesome. I changed the spar structure from having to cut the ribs as shown on the plans to simply laying in a top and bottom spar.
2. The plans show a wood stab control horn attached to one stab panel much like the Windfree kit. Now you have a choice of building the 970 with the horn attached to the stab outside the fuse or locate the horn inside the fin.

Fin

1. The fin parts have eliminated the balanced rudder profile that was so popular back in the Seventies. A balanced rudder can be constructed from the parts furnished by cutting and gluing the fin parts to match the plan.
2. The fin post width was reduced to allow the location of an interior stab control horn.
3. Two 1/16" fin sides are included for those that will construct the fin with the interior stab control horn.
4. Use the outline furnished to cut the fin for an interior stab horn.

Non Laser cut parts furnished that are not on the plan.

1. 3/16" sq fuse longerons.
2. 1/8 x 1/2" spruce wing spars.
3. 1/2" wide vertical shear webs and additional 1/16" balsa shear webs for both sides of spars.
4. 1/16" horizontal grain plywood spar shear webs.
5. 1/8 x 3/16" stab spars.
6. 5/16 x 1-1/4" spoiler blades and framing sticks.
7. Two 1/8 x 1-7/8" Spruce nose block fairing sticks.
8. Balsa Canopy block.
9. 1/4x 1-1/8 x 5" hardwood to be cut into two pieces and used for canopy spacers. Glue to bottom of canopy block before installing front fuse bottom and sanding block.
10. Two eye screws and rubber band for canopy hold down.
11. Two eye screws and rubber bands for wing hold on through fuse, requires builder to make passage holes in fuse sides.

This is how I placed the fuse longerons. The top longeron stops 2 7/8" and the bottom longeron 1 1/4" from end of fuse sides. This allows the interior stab control horn to move freely and the fin post to be sandwiched between the fuse sides for greater strength. The forward ends of the longerons are beveled to allow the balsa block to fit on top of them. Mark the location of the rear fuse formers before installing the uprights. Bevel the ends of the longerons to allow the fin post to fit flush against the fuse sides.

The stab ribs are scaled so the root is approximately 1/16 larger than the plans, do not sand the ribs or jigs to match the plan. Use the spar line on the plan as a guide. All the ribs will need to be beveled to compensate for the angle of the leading and trailing edge for a good glue joint.

The all flying stab has a symmetrical airfoil. Construction is aided by three ribs actually designed as construction jigs. The trailing edge has been cut to perfectly fit flush against the ribs while laying in the jigs, so no sanding is needed. The jigs are designed to allow wax paper to be slipped under the front and rear ends of the ribs to eliminate the LE and TE sticking to the jigs.

Trial fit the spar notches in the ribs to be sure the spars will be flush with the top of the ribs before assembly. The spar stock size tolerances can vary, I had to use a file to deepen the notches just a tad. The ribs can be glued in before the spars, use a straight edge across the top of the three rib jigs to align the ribs top surfaces or your stab will be wavy. I prefer to place the spar in the three jig ribs first and then the remainder of the ribs, using the straight edge between the LE and the spar to assure alignment. I used wood glue and the weights to make sure the top spar is flush with the tops of the ribs.

The root rib is blocked up above the building board to compensate for the jigs. Install the aluminum tubes with the joiner wires in them in both panels for perfect alignment before removing the three jigs from each panel. Install the plywood root caps after the aluminum tubes are installed, be sure the tubes protrude through the plywood caps.

It doesn't show on the plans, but I will taper the LE as it approaches the tip before sanding it round to eliminate a sharp leading edge at the tip.

Step one:
Ribs have been cut away from the spars edges with a Zona saw and Perma Grit sander to create a gap for the 1/16" plywood horizontal shear webs to be epoxied to the sides of the spars and vertical shear webs. Trial fit plywood shear webs before gluing. Make sure the plywood is contacting these surfaces and not being held away from the sides of the spars by globs of tried glue you didn't remove with the Perma Grit sander. I will be launching my 970 from hot winches and therefore added an extra layer of 1/16 plywood horizontal shear web starting at the root rib. This has a short wing rod, so also use carbon in the spar structures. My top spar in the inner panels will have carbon on the bottom and the top. The plans show a 1/8 x 3/8 spar..not strong enough, that is why my Sky Bench kit is set up for 1/8 x 1/2 spars on the inner panels.

Step two:
Apply slow cure epoxy to the sides of the plywood shear webs and assemble them, then apply epoxy to sides of spars and vertical shear webs. Install the plywood pieces and clamp. Clean up excess epoxy that will squeeze out.

After the horizontal plywood shear webs are installed (do not cut the plywood up into pieces that fit between the ribs, cut the ribs away from the spar instead) Install the brass and aluminum joiner tubes.

Make sure the brass tubes are flush against the plywood and the 1/16" rear alignment wire is horizontal to the wing joiner rod and both the wire and joiner rod are parallel to the building board. The root edges of the wing panels have to be resting flat on the building board. Spot glue 5 minute epoxy to the joiner tubes and then fill cavity around brass tube with a mixture of epoxy and micro balloons. See the next pic for this procedure.

Mods not part of the kit: The stab horn is on the inside of the fin instead of the outside as shown on the construction plan. I have filled the stab spars 4 bays with vertical balsa, capped the stab root and stab fairing block with 1/64 plywood, capped the angled trailing edge with 1/16 balsa and filled the first rib where it meets the trailing edge with balsa. The aluminum pivot tube will be supported by the 1/64 ply on the stab fairing blocks.

The fin leading edge was rounded and streamlined a bit and the stab blocks faired to the fin's streamlined shape contour. The aluminum tubes will be partially filled with balsa to position the shortened piano wire stab connectors in the center of the joiner tube assembly. I have the option of covering the fin assembly with heat shrink plastic or glassing and painting it. I probably will go with glassing it so the fairing block junction with the fin will have a smooth and contoured fit.

The stab with out the wire connector rods weighs one ounce.

OLY II

Sky Bench Aerotech

Proudly presents:
Lee Renaud's
Airtronics OLY ll

This design has been the accepted beginners kit by the R/C Soaring enthusiast for years and is still flown successfully in RES and Nostalgia competition today. It is strong and durable and has taught thousands of R/C pilots to fly sailplanes. See our Sky Bench web site for info on the RES (rudder, elevator and spoilers only) and the Nostalgia classes of flying categories. Also, be sure to review the Wood Crafters page too. The Wood Crafters is an annual event that takes place in Muncie, Indiana at the renowned AMA flying site.

This is a Fun Fly that includes the opportunity to fly in competition events if you so choose. The event is restricted to wood constructed sailplanes only and includes scale aero towing and electrics.

The Sky Bench OLY ll kit has been modified to strengthen the wing and uses a 5/16" diameter wing joiner rod and much longer plywood shear webs (W11). All balsa shear webs that fit between the spars have been changed to vertical grain types as opposed to some of the shear webs shown on the plan that have horizontal grain. The small part in each wing that fits against rib number 1 and is used to retain the rear wing alignment wire has been changed from hard wood to balsa wood. The laser cut plywood root cap has holes cut for the rear alignment wire and will be more than sufficient to retain the wire. All wing ribs, plywood shear webs and poly joint braces are now laser cut for dead on accuracy. The wing plan shows a wire on each wing tip block, this has been eliminated since most builders do not put the upward curve in the tips and makes the wing tips weigh less.

The wing ribs are packaged and stacked in the sequence they are placed on the construction plan.

The fin has been changed from a built up structure to a single laser cut part to increase strength and reduce building time. The rudder has laser cut top and bottom balsa wood block parts and the stab has laser cut tip blocks and center joint brace to reduce building time.

The fuselage now has one piece top and bottom parts to eliminate the time consuming installation of the gross grain fuse top parts. Included in the Sky Bench kit is a laser cut plywood servo and on/off switch tray.

A laser cut plywood fuse former, approximately 7 ¾'' long, has been created to be installed at the top of the rear fuse sides. The rear fuse sides are notched to receive the corresponding tabs on the new part.

An electric motor mount laser cut plywood fuse former is included in the kit for optional electric powered conversion. Notch the fuse sides to match the tabs on the former.

Six rubber bands are included in the kit, crisscross four of them and place two of them straight across the wing.

Refer to the Sky Bench web site "Assembly Tips" page for current up dates on all our kits.

OLY II Wing Construction Tips

Notice: Start the wing construction by placing the trailing edge on the plan first, this way the ribs serve as a guide to locate the spars and then the leading edge. The parts are more accurate than any plan due to the plan 's moisture content and copy machine tolerances.

Notice: Ribs W - 1 (one in each wing panel) are different than the two W - 1A ribs and the three W - 1 B ribs. Before installing ribs W - 1 and the first W-1A, glue in the 1/16 pre cut wing sheeting rectangles located beneath Rib W-1 and the first W-1A ribs. Look at side view of wing panel on the lower left hand side of the plan, notice the bottom spar and 1/4" sq rear spar are placed on the plan and the sheeting butts to them.

Notice: Ribs W - 1A and W - 1B have wider spar notches, This serves as a cutting guide when cutting the ribs away from the spar sides to place the Plywood W - 11 shear webs next to the sides of the spars.

Be sure the spars are in the middle of these wider spar notches.

W -11. 1/16 plywood laser cut spar webs, 2 required per wing panel, one on each side of the inboard wing panel spars. Note one end of W-11 are angled to butt against rib W-1. Use the angled end of W-11 to set the angle of the root rib, W-1.

Do Not Cut W-11 To Fit Between The Ribs.

Install the front W-11 first by cutting the ribs away from the spars, after the brass wing joiner tubes are installed, install the rear W-11.

After the 3/8" vertical balsa shear webs and top spar have been glued in, cut ribs W-1A thru W-1B between the spar and leading edge away from the side of the spar and glue in the front W -11 using slow cure epoxy.

Do not cut rib W-1 away from the side of the spar. W-11 butts to rib W-1.

OLY II Fuse Construction Tips

Sky Bench is continually improving all of our kits and designs with two things in mind, faster building and stronger airframes. Below are some of the updates to the great OLY ll, originally designed by Lee Renaud.

The kit now includes a complete package of DuBro Laser push rods and hardware. This will simplify the push rod installation. Directions are on the DuBro package.

Long 1/64" plywood fuse doublers and 1/8" plywood front fuse sides are used for greater fuse strength. The kit is now also supplied with 1/32" balsa sides to be glued to the outside of the metric size 1/8" ply fuse sides. This will cover the fuse former tabs and make up for the difference in thickness of the ply to create a smooth fuse side. A laser cut 1/8" ply part was created to fit between the fuse sides for the stab to be glued to for greater strength. The new part goes forward several inches to add strength and make alignment easier. I don't want your fuse to look like a banana.

Assemble the right side front plywood, 1/32" balsawood and 1/64" plywood doubler and rear balsawood fuse side first over the plan. Use a very thin application of slow cure epoxy sparingly.

If you use wood glue between the 1/64 and 1/8 the sides will curl due to water content in the wood glue unless you weight the sides down until they are completely dry. And then they might curl a bit if you don't assemble the fuse right away.

Make sure the fuse former tab slots are lined up. Use the tabs on formers one and three to align the tab slots when gluing the 1/64" ply to the 1/8" ply sides.

The triangle sticks located on the front sides/bottom have been eliminated, the two front formers are no longer beveled to accommodate the triangles. The 1/64 ply doublers are much stronger than the triangle sticks.

Some parts may not fit the original OLY ll plan, the parts are accurate.

OLY III

INSTRUCTIONS FOR COMPLETING THE OLY lll

Proudly written by Bob Legue

Items needed to complete your OLY lll

1. Two or more channel radio system.
2. 3 plus rolls covering.
3. 5- minute and 30- minute epoxy.
4. Wood glue
5. Thin CA and accelerator
6. Flux and solder
7. Assorted sand paper

Tools required to complete the OLY lll

1. Zona saw
2. Hobby knife
3. Sanding blocks
4. Square
5. Tape measure
6. 36" straight edge
7. Weights in assorted sizes
8. 40 watt soldering iron

General notes for construction

1. Always build on a flat building board.
2. Protect plans from glue with wax paper or a plan protector of some sort.
3. Read the entire assembly manual before beginning and really understand the building sequence. Study and become familiar with the plans.
4. Glues add weight- use the appropriate glue as well as the right amount. Remember no glue joint has to be stronger than the materials being joined.
5. There are several places in the instructions that state " weigh down and let dry or let cure" this is an important step to keep things straight. Don't rush this step, your reward is a straight, warp free plane that will fly straight. For weights I use simple diving weight as I have them on hand. Always spread the load of weights as evenly as possible to ensure even contact.
6. Protect your self from dust and glue fumes.
7. Always dry fit parts before gluing.
8. There are several steps that require clamping. I used nothing more than simple spring type clothespins for the entire model.
9. It is best to remove excess glues especially at the spar areas while still wet as they will interfere with the fit of the W1 and W2 pieces.

Horizontal stabilizer and elevator assembly:

1. Locate and place both elevator and hardwood connecter against Horizontal stab trailing edge. Place waxed paper over stab at hinge line. Epoxy elevator assembly together. Pin in place against stabilizer and let cure.
   
2. Tape elevator to stab on one side, turn over and flat sand with progressively finer grit paper. Tape sanded side and turn over, remove tape and sand this side. The idea here is to prepare the wood for covering- not to remove excess wood. It is easier to sand this structure now than to try to do it after the ply doublers are in place.
3. Lightly epoxy plywood doubler over stab top using fin alignment holes for alignment. Remove excess epoxy from holes. Weigh down and let cure.
4. Turn stab over and lightly epoxy solid ply doubler directly over upper plywood doubler. Weigh down and let cure. Sand bevel in elevator leading edge and round over perimeter.
   

Fin and Rudder assembly:

1. Lay rudder pieces over plans using straight edge for proper alignment.
2. Wood glue together and let dry.
   
3. Align vertical stabilizer and rudder. Use masking tape and join on one side. Turn over and sand flat using progressively finer sandpaper down to 400 grit. Now tape this side and turn over. Remove tape and repeat sanding process.
4. Epoxy on plywood control horn doublers aligning with pre bored holes. Weigh down to ensure it is flat and let cure.
   
5. Turn over and repeat for other side.
6. Sand bevel in rudder for hinge line. Sand stabilizer/rudder perimeter round.
7. Set aside- you're done.

FUSALAGE

1. Lay fuse bottom parts over plans and glue front plywood to rear balsa pieces.
2. Draw centerline down fuse bottom and all formers.
3. Collect balsa, plywood, and liteply front and rear fuse sides. Make two piles with straight edges facing each other. The order is, 1/64 ply on inside, then the 1/8 lite ply front and rear sides, finally the balsa outside front side tripler.
   
4. Lightly apply epoxy to the front liteply fuse joint and balsa front fuse sides aligning the former holes. The balsa piece should be on the board first so the outside will be flat. Remove excess epoxy from holes. Let dry.
5. Glue front and rear pieces against a straight edge and let dry. Lastly, on the inside of fuse epoxy 1/64 plywood tripler with careful alignment at former holes. Clean holes of glue if necessary. Weigh down and let dry. Repeat for other side making sure you build it opposite to the first one so you end up with a left and right side.
   
6. Lay either fuse side on its side with outside facing down, glue in formers 1 and three square to fuse side.
7. Cut and epoxy in spruce fuse side stiffener.
8. Continue to glue remaining formers 2, 4 5, and 6. The continued use of a square here will yield a perfect form. Glue in servo tray.
9. Coat all formers with glue and place other fuse side on top, check tail and nose for plumb then weigh down and let dry. If nose and tail ends are not exactly plumb you will get improper wing alignment. Take your time here, check and recheck.
10. Glue fuse assembly over fuse bottom aligning the fuse and former centerlines, weigh down and let dry.
    

    (RAY'S NOTES: I always put the fuse bottom on last to make it easy to access the push rods and locate the servo tray to match the height of the particular servos I will install. Also, the fuse top is the most important part for fuse strength, I glue carbon to the underside before installing the top and with the bottom off, I can double glue the top part to the sides easily from the bottom.)

    Add the tail post block between the rear fuse sides as you go. Epoxy nose block into position making sure it is square to fuse bottom, clamp sides and let dry.
11. Epoxy plywood and spruce stick tow hook mount in center of fuse.
12. Through the fuse sides, slip one brass wing rod tube and one aluminum wing alignment tube and center in fuse. Measure from brass tubes to tail center of plane and adjust if necessary to get the same measurements. When satisfied rough up tubes and epoxy in place. Use a lot of glue here.
13. Prepare plywood wing roots for servo leads or tubing if you are going to install spoilers. Do all four roots at once to maintain alignment.
14. Epoxy one set of plywood wing roots to fuse sides, when dry sand off any exposed tube flush with wing roots. The other ply wing caps are for the wing.
15. Pushrod time. Run the two music wire pushrods through the formers and make adjustments NOW for ease of operation. When satisfied with them install with Z bend to rear of plane. Take the third short music wire and cut in half. Assemble roll joiner between the cut front and rear music wires and solder joint inside of fuse. When cooled give a good tug from both ends at once to test. **
16. Place horizontal stab and elevator on fuse rear with the trailing edge of the stab at the cut out and mark front of stab on fuse. This becomes the mark for the balsa fuse top. Epoxy in plywood horizontal stab support flush with fuse top then the balsa fuse top on top of that. The laser cut balsa top will extend above the fuse sides for shaping.
17. The balsa canopy block is marked down the center as well as the canopy spacers before gluing together. Sand the block to fit the fuse. Now line up all those marks and glue together.
18. Route spoiler servo leads through fuse before gluing in the fuse top blocks. Notch out fuse top balsa blocks on bottom side to clear wing tubes. Check fit and glue in place. *
19. Carve, sand, and sand some more to shape fuse as shown on plans on plans. Use finer and finer grades of paper for best results.
20. You may finish the entire fuse, stab, and rudder covering now. Don't forget to leave a strip of covering off where the fin and the stab glues together as well as the stab to fuse joint.

* I converted the fuse to have this piece removable, only used cut off and scrap wood out of the kit to do it-no added wood.

** I used HS85MG.

THOSE BIG BEAUTIFUL WINGS!!

1. Align lower trailing edge sheet with straight edge and pin down. Take 3 or 4 number 5-15 ribs to set spacing for leading edge sheet and pin down. Mark position of ribs 1,2,3, and 4 on both LE and TE sheeting. Cut and fit the inboard center lower sheeting to LE and TE. Draw the marks on the sheeting for ribs one thru four.
   
2. Lower spar placement is done using a few ribs for positioning. Glue spar while cross pinning across spar. Weigh down and let dry. If you choose to add carbon fiber tape to spar sand relief into lower leading edge sheet the thickness of your tape and glue with epoxy the tape to the sheeting and the spar to the tape all at once. Of course this is optional.
   
3. Install the innermost rib #1 using W1 to set angle of rib.
4. Starting at the outboard end of inner panel begin gluing a rib then a shear web, rib then a shear web until you get to the last 5-15 rib. The ribs will only get glued from 1 inch in front of spar. The rear of the ribs located behind the spar can be glued to the end of the rib. Temporarily install the top spar without glue and apply weight across the entire span, let dry.
   

   (RAY'S NOTES: Before setting in the ribs and shear web blocks, Check each rib at each rib location to be sure the bottom spar notch of the rib is deep enough to allow the rib to fit down on the spar with the bottom of the rib fully resting on the bottom sheeting. Why? Well it isn't because the rib notches are incorrect or erratic, the spruce spar is the culprit. The thickness and width of each spar can vary, if you don't perform this check, the bottom sheeting (airfoil) will be distorted. And also look poorly constructed after the covering is put on. When placing the ribs, I ca the rib to the rear sheeting and from the back edge of the front sheeting forward to where the bottom of the rib starts the Phillips entry curve all in one step. Wood glue or epoxy work fine on the shear web blocks. If carbon is epoxied to the top of the bottom spar, then use epoxy to glue in the shear web blocks.)

5. In the same fashion glue in ribs17 to 23. Save rib #16 until after the wing panels are joined together. Again place in top spar and weigh down, let dry.
6. Glue in top inboard spar now and use lots of weight. Let dry.
   
7. Cut notches in ribs in front of spar to clear W1 and epoxy in front of spar. Use lots of clamps here. I used 3 spring type clothespins between each rib. Let cure.
8. Glue front end of ribs 2-4 to spar and lower sheeting for about an inch. Add remaining 3/8-inch shear webs. Now glue in rear ribs 2-4 full length to lower sheeting over lines on lower 1/16 inch sheeting.
9. Cut and sand to shape all outboard shear webs then glue into position.
10. Glue in top outboard spar. Weigh down and let dry.
11. Sand lower TE sheeting on both inboard and outboard panels from end of ribs to back edge of sheeting, full depth at rib end to nothing at TE. Put wood glue on top of all ribs from the cutout to the back of sheet, then all across the very back of the lower TE sheeting. Place the top 1/16 inch TE sheeting up to the notches and weigh down and let dry.
12. Notch ribs for W1B and epoxy in place, again use plenty of clamps. Let cure.
13. Cut out inboard ribs for the plywood polyhedral joiners, test fit and epoxy in place. Clamp securely. Let cure. Sand outboard panel to proper angle, raise panel to 5-3/4 inches and epoxy joiner to outboard panel, let cure.
14. Rib #16 may be installed against the outermost rib # 5-15.
15. Glue in all front and rear 1/16 inch vertical balsa shear webs along both inboard and outboard panels, clamp and let dry.
16. Saw off all excess spar and sheeting from wing panels. Save cut offs.
17. Rough up wing joiner tubes with sandpaper. Cap one end of wing tube with scrap sheeting and CA in place. Use only a little glue here and kick it with accelerator. Sand sheeting flush with outside of tube. You can cut the sheeting plugs using the tube as a " cookie cutter ". Just press one end of tube into scrap 1/16 inch sheeting while turning the tube.
18. Cut the rear of the ribs behind the spar and dry fit W2. This has to fit flush to the spars and not stick up past top spar. Complete contact must be made at top and bottom spar for the full length.
19. Place tube through rib #1 with 1/8 inch hanging out past rib #1 and touching the bottom spar, spot glue with 5-minute epoxy, let cure. Mix up a slurry of epoxy and micro balloons place wing on LE and completely fill around tube with slurry. Coat W2 with epoxy and place into position and clamp it fully down the length of itself to the spar and rib #1. Let cure.
20. With wing secured and weighted down flat to the building board begin gluing leading edge sheeting to front end of ribs. Starting in center of panel lift sheeting up to rib just until it touches and drip thin CA down rib. Let cure naturally while holding in place. If you kick this glue joint most likely it will expand and distort the airfoil. This is a good place to build in a warp, check frequently that the entire wing is flat to table. Continue gluing ribs to sheeting by gluing the next rib to the right, then the next one to the left and so on.
21. Sand lower wing sheeting to face of all ribs. Place a strip of masking tape on lower sheeting at each rib. Leave 2-3 inches of tape in front to hold down top sheeting for next step.
22. Put wood glue on top of all outboard ribs to sheeting notch and across the full length of the spar. Place top sheeting in place and glue rear of sheeting in place with thin CA. Starting in center of panel, roll sheeting down against ribs and hold in place with the masking tape. Continue in a left then right pattern pulling down the sheeting until all sheeting is secured, let dry. Now do inboard panel.
23. When dry sand top LE sheeting flush with ribs. Add wood glue to all ribs and sheeting, hold in place with masking tape at each rib and let dry. When dry cut off LE and remaining excess material flush with last rib.
24. Install wing alignment block and tube. If you are going to add spoilers route the servo leads or pull string tubes thru the wing now. Cut and glue inboard top center sheeting.
25. Coat wing tip block with epoxy and place on outboard panel at last rib so it is flush with top of last rib, pin in two places from inside of rib and let cure.
26. Carve and sand LE and wing tip to shape as shown on plans. Then sand some more with finer grade sandpaper. Wing trailing edge will be 1/16 inch thick. Epoxy inboard ply root rib over joiner tubes and let cure, they are slightly oversize so you may sand them to your wings final shape. Sand and remaining tubing off and deburr inside of tube with the back of your hobby knife blade. If installing optional spoilers do these now as indicated on plans.
27. Build opposite wing in exact fashion and order.
28. Put wings together on wing joiner rod and alignment wire, fully insert the rod into both wings. Turn the wings over and check for balance. I use a loop of kite string over both wires in the center and place a small amount of weight on the outermost rib until it balances. You may now cover your wings

FINAL ASSEMBLY

1. With your choice of hinges, hinge tape is not supplied, hinge the elevator to the horizontal stabilizer. Then hinge the rudder to the fin.
2. Install control horns then remove. Place a drop of thin CA in each screw hole.
3. Drill 4 or 5 3/32 inch holes in the stabilizer ply mount randomly. This forms epoxy nails and eliminates the need for additional glue support.
4. Epoxy the rudder and fin assembly into the stabilizer. Place square against both sides of fin to ensure it is perpendicular. Hold in place with masking tape from end of stabilizer across the fin top and across to other end of stabilizer until cured.
5. Epoxy the stabilizer and fin assembly to the ply stabilizer mount, Measure from center of front fuse [I place a T pin in center of forward most fuse former and measure from there] to outward stabilizer hinge line until both numbers are exactly the same. A second check for square will be from wing trailing edge to hinge line, these should be the same also. Finally view plane from rear and adjus