Jim Ealy's photo/text report on the Baby Bowlus Albatross

Building the Bowlus BA-100 - Part 1

The kit is complete! All you need is the strip wood/sheeting. The beautifully laser cut parts are all placed in separate bags and labeled. The parts are cut as per MB plan and they are all very accurate. Unfortunately, my plans were old and had shrunk about 2%. My wing span would have been 120"+ instead of the 122 and 3/8". Check your plans when you get them. You can do one of two things: "mark off" on the plans, the new positions for the ribs, formers or go to a print shop and enlarge them. I elected the easy way, to print mine at 101.8%, Most print shop today will have a digital copier. The owner of the print shop where I have my plans produced is an old AT-6 pilot.... Lay out each kit piece and mark it in ink, "w1", "w2" etc, rudder TE, stab TE, etc. You will not be sorry!!!!

I just finished the right wing and these are a few things (suggestions) I would do or did differently.

Maybe "caveats" is a better word.

1. Build wing upside down. The top spar remains flat (as per full scale) and the bottom spar rises to meet the top spar at the wing tip. This adds more effective dihedral. I raised my tip by1/2" to get the top spar flat. (I also hate plans with only one wing layout!!! You can raise one wing tip and then build the other wing upside down, to keep from having to retrace the wing or use oil to make the plans transparent.)

2. Over lap ply/balsa sheeting over the spars. This adds strength. If you do, you will NEED to notch spar cutouts in ribs deeper.

3. Use 1/16" balsa sheeting instead of 1/32" ply – balsa is strong enough and ply doesn't look like mahogany that is on the full scale, anyway. I will use a mahogany stain over super coverite.

4. The 5 and 1/2" wing rod tube can be 3/8" ID brass or carbon. You can use a straight 3/8 rod and slope the wing rod tube down at the fourth rib by 3/16". After wing was built, I used a long rat tailed file to sand the pre-existing holes down. You could do this before they are glued in place, as well. You can also, use the pre-existing holes and buy a 3/8" rod with 3% dihedral. See pics

5. I used vertical 1/4" hard balsa sheer webs instead of 1/64 ply.

6. I added a drag spar. See pics.

7. The outer wing bay is funny. All previous wing bays are 2 and 1/2 and the last bay is 2 and 7/8. On all of my documentation, including pictures of N25605, all wing bays have the same separation?

8. The aileron's length on the plans differs from the documentation and pictures of N25605. All of my documentation shows an aileron that is 88% the length of the inner panel, but the plans show a 92% aileron span. If the outer wing bay was made smaller to match the other wing bays, and the inner panel increased by 3/8", then the spans would better agree with the documentation. To be sure, owners did "redo" the BA, but some things would have been very hard to change; as the wing' s LE to spar came pre built.

9. You can buy four 5 foot 1/4" square spruce spars or you can splice a 48" spar at w7-w8 and use a full depth ply sheer web on both sides.

10. On my documentation, the LE sweeps backward at the aileron junction AND at the w10. On the plans, this secondary reward sweep doesn't begin until, w-11. Change it to w10.

11. W3 seems strange to me, BUT it is cut as per plan! The forward portion is too long and the rearward portion too short. The LE sweep should be straight from W2 to W10.

12. I will use a 1/2" by 3/8" hard balsa LE edge INSTEAD of the 1/4 square spruce on a diagonal. You can easily cut the front off of the ribs and then use the 1/2 by 3/8 LE. Much EASIER to get the correct LE airfoil shape. If you are still concerned about LE dings, use 1/2 by 1/4 balsa and 1/2 by 1/8 spruce laminated.

13. I used 1/8" lite ply sheer webs on the front side (wing rod tube is flush with spars) of the wing rod tube. After tilting the wing up on its LE, I then filled in the spaces between the spars and the tube with 15 min epoxy mixed with micro balloons.

14. I am also having trouble with the boom. The documentation shows the Dural boom as 5 inches in diameter for the full scale. The plan's scale is 2.75" to 12" If you divide 12.0" by 2.75 " the plan's scale is 1/4.36. That would make a scaled 5" boom 1.15" (about 1 and 1/8") NOT 1.00". For the boom to be 1.00" as per the plans – the scale would need to be 1/5 scale: 2.4" per foot? Any suggestions?

15. The amount of "top to bottom" taper on the LE of the aileron is insufficient, I used a 1/8 by 1/16 ply spar on the bottom of the aileron. This allows more than the 1/4" movement.

16. I really like hinge tape, but that is not going to look scale, so I am still trying to decide how to hinge the ailerons.

17. If you use the 1/4 square LE, you are going to be really upset. The LE rib notches are only 3/16 and you will need to razor plane off 1/32 on top and bottom. HOPEFULLY you will not "nick" any ribs???? Yea?? Use 3/16 square. The call-out on the wing plan is for 1/4 square, but on the rib plan, it is obviously 3/16?

18. The wing spar sweeps backwards on the plan at w3. The total sweep at the tip is a little more than 1/4 inch. That would only be a little more than 1.25 inch on the full scale ship. I cannot see any spar sweep on my documentation and do not know why a 1.25 inch sweep would be designed into the spar. The full scales ships I've seen with spar sweep use a splice and it is more than 1/25 inches. And on the full scale a one-inch spar sweep doesn't seem to make sense to me? Both of my wings have the spar sweep. I did not discover the sweep until both wings were finished and I looked down the wing – wow is that disconcerting.

I used twisted servo wire from ACE, HS81 servos for the spoiler and aileron. I do not know if I will need to use a HS225 for the aileron. I am not sure if I like the 1/32 aileron spar cap. I might choose to use balsa sheer webs instead. The aileron diagonals are a headache. Since the wire TE is a pain in the butt, Ray has cut 1/4" stock TEs. However, now the diagonals will not match the full scale ship in an overhead view. So choose a paint scheme that is not transparent!

The next installment will be a step by step set of pictures and directions for building the wings. I'd really like to build this ship at 1/3 scale!

Building the Bowlus BA-100 - Part 2, Wings

1. Number all ribs and place them over the plans. Cut out any additional holes for servo wires and servos.

2. Splice the 1/4 square spars. Splice the top one in one direction and the bottom in the opposite direction. Easiest way to get the splice exact, is to lay both spar pieces on top one another and saw at angle that will be fives time longer than the spar is wide. CA and clamp. Cut spar to length.

3. Place ribs on spar upside down. So the top spar remains flat.

4. You can CA all ribs in position and then add webbing as I did. Many builders will cut all webbing first and then glue rib, web, rib, web, etc.

5. Add bottom spar, I used lead bricks and lead bag to press spar against webbbng. The 25 lb bags of lead shot are available from gun shops for a very reasonable price and then you have lead shot for balancing.

6. Add TE after notching with saw. Lift up LE to give the correct curvature to the TE. I have several hack saw blades glued together to produce a certain thickness and I glue a 1/4 square fence on both sides of the bundled blades to give me the correct depth. May take an hour to make up 5 or 6, but then it's done for future use.

7. Clamp LE in place. Add additional ply shear webs over spar splices. Plans call-out is for 1/4 square. But the notches and the wing-cross section show 3/16. Use 3/16 as that will reduce the amount of planing.

8. Add sub spars for ailerons. Add wing tip. Be sure to have the bottom aileron's sub spar only 1/8 by 1/16. This will give the proper clearance for the small amount of down movement needed.

9. Adjust holes for wing rod tube. I tilted my tube down at rib #4 and will use a straight wing rod. (cheaper way to go) You can leave the holes as cut and purchase a wing rod with 3o of dihedral.

10. Cut ribs between sub spars.

11. Cut , CA and clamp the 1/32 sub spar shear web in place. Repeat for the aileron.

12. Add bottom 1/16 balsa sheeting. Spray with CA accelerator before attaching. Works like a charm. I prop up the LE of the sheeting with extra TE. Choose the proper size needed for each position. Hold in place with lead bags.

13. Cut holes, if not already done for servo. I use 1/4 square for rails on back side of rib. Cut hole through shear web. Run servo wires. I buy twisted servo wire from Custom Electronics, the same address as the old ACE company. ( A cheaper method) Buy 24 gauge from Radio Shack, etc. Clamp the ends of THREE stands (10-15 feet) together in vise. Stretch it out, clamp the other end in Dremel Tool and twist. Takes maybe 2 minutes for entire process. (20 seconds of Dremel time)

14. Add 1/16 top sheeting. Spray with accelerator. Weigh down with lead bags.

15. Add 1/4 x 1/8 spruce drag spars top and bottom. Add 1/2 x 1/4 wing alignment rod support between drag spars. Be sure to remember where you place the support!

16. Add drag spar as per first set of pictures. Cover with 1/16 balsa.

17. Add tip sheeting.

18. Add 1/4 x 1/2 balsa hinge support on backside of aileron spar caps. I used hinges that come apart by removing hinge pin. I'll CA in place later. Place hinges at top of the sub spar. The aileron is only straight for a few bays and the hinge position cannot extend beyond the straight portion, or they will bind. Mine are placed in the first full aileron bay and against W8. Trim the TE with a razor plane. If you choose to use hinge tape, stop the tape at W8 for same reason.

19. Add diagonal aileron braces to suit your tastes.

20. Sand entire surface to shape.

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New! l-26 Construction Article by Karl Cassidy of Ireland New!

Thanks Karl for taking the time to share your l-26 building experience, I'm sure it will be helpful and interesting to many builders regardless of their building skills. Building and flying scale sailplanes is probably the ultimate building experience for most woody builders. The builder has the option of adding as much scale detail he desires and the feeling of accomplishment and pride doesn't get any higher.

Karl's text will not be edited, it will go up as it is received. Of interest, Steve Moskal, who has flown in Wood Crafter's annual Soar In Reunion each Memorial Day weekend drew the plans that are being used in this kit. I hope that we will have an l-26 flying in Wood Crafters 2004 where we have a growing interest in our Aero Tow event. We also provide electric winch launching for scale sailplanes. Ray

Here is Karl's first installment

Hi Ray,

Please find first part of "diary" Below. This bit is a bit long-winded being the first part! Others will be shorter. If you need more pics, just let me konw what you want. Please feel free to edit it down as you see fit if required.

Oh BTW, I saw the TAM 5 in the window of a modelshop in Cork. (I even touched it!) It looks like a bog-standard slightly tatty sports model! Balsa, clear heatshrink cover, the whole lot. Unreal to think it crossed the pond. (I was expecting an all-molded hyper-efficient job!) Hope all is well with you.

regards, Karl.

Skybench Aerotech 1/4 Scale Schweizer 1-26 Construction "Diary"

What's All This About Then?

Having purchased a 1/4 scale semi-kit for the Schweizer 1-26 from Skybench Aerotech, I've been asked to document the construction of the model. This is to give you an idea of what to expect if you're thinking of buying the semi-kit, or if you have the kit, the luxury of learning from some of my mistakes as I go along. Of course, should you be a master craftsman, you'll find it highly amusing to watch me blunder along! I hope to add to this every 2 weeks or so, as I go along.

I wanted a 1/4 scale built-up model as a "project" for a while now. I was looking at buying the Flair K8 kit when someone showed up at our slope with one. Rats! Can't be seen to be copying can I? That's when I found the 1-26. (It won't get mixed up with the K8 anyhow!) Maybe 1-26's are two a penny in the US on slopes, but not on this side of the Atlantic..

I'll point out right now I have no commercial or personal relationship with Skybench, or anybody associated with same. My diary will be "warts and all". I live in Ireland, am 29, and have been involved in R/C gliding for about 12 years. (Though I got my first go on the sticks at 7 years of age on one of my Dad's slopers. I still have that model too!) I've built oodles (about 20) of foam/veneer/glass models, maybe seven or eight "built up" kits and 3 models from plans. So I'd describe myself as an "average" modeler in building skill terms.

Flying wise I've flown all-molded, 4 meter stuff, foamies, just about anything with wings, so in the flying department I'd say I'm comfortable with most planes, I suppose "good sports flier" standard would be fair. Enough about me, on with the diary!

So What's In The Kit?

Rather a lot actually! The first thing I noticed was the ribs. They're beautifully finished, there's a lot of them, and they look very big! This is my first 1/4 scale project, my previous scale models have all been 1/5 scale. The ply parts are beautifully finished too. The kit includes all the cut parts, plus some "extras" like cut pieces for the rudder and tail tips. Overall it's as good a kit as I've ever seen. Obviously, being a semi-kit, you provide your own sheet and strip wood. (Though some sheet parts like the tail feathers ARE included in the semi-kit.) If you allow for the cost of the two-sheet plan, the kit is very good value in my opinion.

What About The Plan?

The design is from a third party source, well drawn and is pretty clear. A few more cross-section views and notes would have been nice, but after a bit of head scratching, most of it can be figured out. I would not recommend this as a first built-up model, as it is a reasonably complex project, perhaps if you've built a few kit-build wooden gliders of reasonable complexity you'd be okay. Apparently this was the designers "most ambitious project to date" (Isin't the net great for research?) and the design shows it a little.

The wings show glass cloth on the root portions, out to maybe 18" span. I feel this is serious overkill. (If the spar isin't up to it, the cloth won't help much anyhow!) Modern thinking is it's better to let the wing flex naturally, rather than try and over-stiffen it. This flexing spreads the loads along its span. Maybe if you're going to try and zoom-launch off a winch you'd glass. I'm flying slope, so I'll be leaving this off for sure. (And if the wing snaps, I can come back here and eat my words later!) The other change will be the placing of servos in the wings for spoilers and ailerons. (One servo for each surface) I don't do bellcranks anymore, especially not at this scale!

Let Glueing Commence! (27/8/03) I decided to start with the tail surfaces first. These are balsa sheet with spruce "spars" at the hingelines on all surfaces, with the strut framework built up in 1/8" balsa strip. The first snag here was the fact that the spruce is 3/8" high. The plan isin't too clear on this point, but eventually I decided to build the 1/8" strip up in a staircase sense, (see picture) to be sanded smooth afterwards. I'm pretty sure this is what the plan means if the tailplane cross-section view on the fuselage drawing is consulted.

Balsa joints

There's more work than I expected in the tail surfaces, though the result is light and VERY strong, always a good thing in a low-mounted tail on the slope when it comes to landing!

Below is the completed but unsanded tailplane and elevator. (The elvator is the bigger piece!) The ruler in the middle is 6", to give scale.

Tail in the nude

I have the fin about 2/3rd of the way done at the minute, so hopefully by next time the tail feathers will be finished and sanded, and the fuselage can be started. Oh, if you're going to build this model, buy a balsa stripper. You'll save a FORTUNE in strip wood. The tail and fin would use maybe 25 36" 1/8"sq balsa sticks if you bought them in a model shop, so it'll pay for itself straight off! Until next time..

Here is Karl's second installment

As mentioned last time, I was finishing the fin and rudder. The trailing edge of the rudder has a VERY tight curve on the lower half. (It's tighter than it looks in the photo!) The plan shows to bend 1/8" square around this curvature. After maybe an hours worth of steaming/bending/breaking I finally got a piece around the curve on each side! I definitely recommend laminating this piece in a curve from 2 thicknesses of 1/16" balsa instead, it'll be a LOT easier! (Probably a bit stronger too.) Picture shows rudder and fin sanded to shape.


With the tail built, I'd normally build the wings next. However due to a Ireland-wide shortage of 3/8" by 1/8" spruce for wing spars, I've had to order it from the UK. So instead I've decided to break a long-standing habit and build the fuselage first. This is the part that has the most constructional features that are new to me. It's a little like a Slingsby Gull fuselage I have the plan and construction article for, so I've gone about it in the same way. Maybe there's a better way to do this bit, but I don't know it!

The fuselage is built around a ply keel. (Nicely cut in the semi-kit of course.) the keel was placed flat on the building board and the doubler and bulkheads glued to it. The planking between the second and third lower bulkhead (B3 & C3) was then done on this side, to help hold everything square. At this point, a problem was discovered! The bulkhead B (Second one from the nose) is cut in the kit exactly as per plan. However, the bulkhead is then too short compared with the fuselage drawing and the ply keel! you can get round this by positioning the bulkhead a little lower and building up the top edge. I decided to cut two new ones instead. This is NOT an error in the kit, rather an error in the plan. (If this upsets you, you've obviously never built from a plan before!) Minor error, but one that could catch you out if the whole fuse was built before you tried planking .

Fuse/Keel on the bench

The keel was removed from the board, and the bulkheads, doublers, etc. fixed to the other side. The Transverse sheeting and bulkheads for supporting the wing root area were then fitted.

Fuse/Keel removed from plan

Next stop is to start to fit the spruce stringers for the rear fuselage and the wing root plates. Until again...

Here is Karl's third installment

Turning to the rear half of the fuselage, I started by making up the two "sides". (The rear fuselage is basically a box fuselage with external stringers.) Spruce longerons were bonded to the root plates as shown:

Longerons on Root Plates

The space between the spruce was infilled to the rear canopy edge with lite-ply, then a ply doubler bonded over this. Cross-grain sheeting in balsa between the two spruce longerons completed the sides:

Lite-ply and balsa sheeting

These sides were then attached to the fuselage front section as shown:

Side attached to front

Using a straight line on the building board (Ensure it IS straight!) and marking the centre of each former, the two rear sides were carefully brought together ensuring everything was kept straight and the formers bonded in place. The bottom sheeting was then fixed, ensuring the widths matched the top stringer formers. (Maybe it's time I made a proper fuselage jig too, to avoid embarrassing pictures like this one!)

Homemade fuselage non-jig

Also visible on the bench in the last picture is the lower spruce keelpiece with balsa spacers bonded to it. This was then fixed in place, again being very careful about alignment. I added some small ply plates to reinforce the junction between the front ply keel and this spruce longeron. The triangular gussets were then fixed. Ensure the grain runs parallel with the LONG side of the triangle, as shown on the plan. It makes these parts a bit fiddly to cut out, but they will have far less strength if the grain isn't oriented correctly here.

Careful with the triangular gussets

Having sorted out pushrod openings, (I'm using carbon tube pushrods for the tail surfaces, there's enough room for two pushrods in this tubby fuselage!) the top stringer formers were fixed, followed by the stringers. The top stringer is spruce as per plan. However the other stringers are omitted from the plan for clarity. The first former is slotted for the stringers, but not the others, the stringers being "let in" to these formers during construction. I felt all spruce would be overkill here, so the other stringers are basswood. Consulting the tiny 3 view on the plan corner, it correctly shows that all stringers do NOT run to the very rear. (I confirmed this from a Schweizer company drawing reproduced in the excellent book "Sailplanes by Schweizer" by Paul Schweizer and Martin Simons.) The two lowest stringer terminates at the first former, the next one goes to the very rear, and the last one ends at the second-last former. (see photo)

Whare the stringers end

When letting in stringers into the formers, do NOT let them in fully. The formers should not be visible when covered, in other words the strings should sit a little proud:

Proud Stringers

So, progress moves apace, and we have something that's starting to look a little less like a wheelbarrow and slightly more like an aircraft now! Until next time!

Here is Karl's fourth installment

Hi Ray,

The project continues apace, as you can see! Please be aware I was off work this week, so I got a LOT more done than usual. I won't be able to keep this up from now on!

BTW, I ordered spruce from a second UK supplier, and got yet MORE basswood. I phoned them and they said they consider spruce and bass "interchangable". I politely suggested my 1/4 sclae glider wing spar might not feel quite the same about the whole matter! It looks like I've no choice to use my German metric-sawn stuff. It's as close to the thickness (1/8") as makes no difference, but it's fractionally wider (Probably 7/32 rather than 3/16") so I guess I'll go with that. I'd prefer a decent spar even if it adds a little work for me letting out all the ribs...

Anyhow, here's the next 2 bits:

Next step was to build up the wheel well as shown on the plan: (Spruce 1/8"sq stringers not yet added in this picture.)

Wheel well

From the start of this project I was in two minds about the cockpit. As built it had a "deck" in it, only allowing a pilot bust. I feel at this scale a full pilot figure really adds to the look of the model on the ground. Therefore I decided to engage in a little "radical" surgery to facilitate this. First I removed the transverse sheeting between the wing root plates back to bulkhead C3, before opening out bulkheads B3 as shown:


The keel was then reinforced in this area with two lengths of 1/4" by 1/2" spruce, as shown in the photo below by red arrows. The green dashed line shows where a heavy spruce "anti-crush" cross-brace will eventually go between the two wing root leading edges.

Keel reinforcement

The other side of the cockpit area was then planked, before the whole area was lined with carbon tows across the planking and around the edges, and glass cloth throughout. This was then left to cure for 48 hours. Overall these additions should more than cover the structure removed! (While the cockpit will not be true scale in that there should be no centre-keel below the instrument panel area for example, it will still look a lot better for having a full-size 1/4 scale pilot figure in place.)

Cockpit area

The next step was fitting the front fuselage "stringers" These are actually substantial ply shapes, (Shape K on plan) bonded between bulkhead B and the nose bulkhead A.

The plan does not show the positions for these for clarity. Refering once again to published 3-views and fullsize palns, I did it as follows:

1. One of the pieces should run in line with the cockpit canopy sill. This is fitted first.
2. The next piece below should be at right angles to bulhead B. The appearance is as shown below:

Front stringers on Bulkhead B

Two more shapes are then added above, and two more below, these two pieces, these being spaced equally. Someone with access to a fullsize 1-26 may correct me here, but I feel this will leave an appearance close enough to fullsize to fool anyone who doesn't put a ruler on your model! (The battery has been repositioned BTW, as I intend to install an aerotow release.) Final picture shows all the shapes "k" in place, and the fuselage structure almost finished.

Shapes 'k' in place

Here is Karl's fifth installment

I've spent a lot of time sorting out a canopy. I've pulled canopies before, but nothing as big as this. Suffice to say, it did NOT go entirely as planned. So, conceding defeat, my canopy plug has been sent to England, where it shall be professionally vac-formed.

Having been delayed by this, I finally got a chance to start the wings. These are absolutely conventional construction, so no suprises here! as mentioned before, I had toyed with the idea of modifying the structure to match the skin/fabric layout of the fullsize. However, given the ribs are not scale (The model has a LOT more of them!) the easiest way to improve scale fidelity would probably be to skin the whole wing as per the SGS 1-26B model. The particular colour scheme I'm going to model is a 1-26A, so I'm going to build as per the plan and live with the slight scale deviations.

Given that a whole bunch of photos of a standard (if large!) balss/spruce wing being built is hardly a thrill a moment, there will only be one or two pictures each time. So far, I've managed to lay out all the ribs on the spars and leading edge, and also construct the wing joiner boxes at the root-end of the spars:

Wing being built - rib layout

Here is Karl's sixth installment

Having had a flurry of social engagements the last while, the poor 1-26 project ground to a halt. However, with the weather becoming less ameanable to flying, and my social diary clear for the next while, it's full steam ahead! The wings have had the spars all webbed, followed by the lower trailing edge and lower D-Box sheeting. The upper trailing edge sheet was then affixed, and the upper D-box sheeting added. Obviously the wing needs to be firmly pinned to a flat surface, with suitably planned spruce stock to ensure the 1/8" washout under the trailing edge is built in. As can be seen in the picture, I'm midway through this, with the second wing upper D-box sheeting yet to be added. I've also started to look at where my cabling and wing servos need to go. Once I close the D-box sheeting on the other wing, I'll be sorting out the wing servo mounts.

Wire in the wing

One piece of good news however, my canopies have finally arrived! Hooray! It's may be just a piece of clear plastic to you, but given the effort it took to get to this stage, I think it deserves a picture!

Clear canopy

Hopefully future installments will resume a more regular pattern for the next while! Until again...

Here is Karl's seventh installment

Work continues rather slowly at the minute I'm afraid. There just aren't enough hours in the day! Anyhow, the D-boxes and trailing edges are fully sheeted, the lower spar caps are in place, as are the upper spar caps on the outer section. The servos are fitted into the wings and leads soldered on and run through the wings. The original plan shows two fuselage mounted servos driving ailerons and spoilers. I prefer wing mounting, especially at this scale. I fitted two spruce blocks to the outer edge of the ribs each side of where the servos were to go. A 1/16" ply plate was fixed to this using four 2.5mm countersunk screws. (I like to be able to get them out again if I have to!) I affixed servos by epoxying them directly to the plates, a bad habit I learned building all-molded stuff! I use tape around the servo first, then epoxy that to the ply. Heat-shrink around the servo works really nicely too. Naturally I've fitted four servos in total, 2 for the ailerons, two for the spoilers.

I'm using Multiplex Cockpit BB servos, which are a decent middle-range micro servo. I don't intend to fly F3F style with this, so I can leave the metal-gear digital servos on the shelf! Note in the picture of the installation that to allow alignment with the wing-mounted servo, the control horn reinforcement riblets in the aileron need to be offset in the bay, .i.e.. NOT in the middle of the bay as on the plan. You can see the glue marks where I had them in the wrong place originally!

Servo mounting

Next on the agenda is the fitting and setting up of the spoilers. Once this is done I can complete the top sheeting of the wing. Until again...

Here is Karl's eigth installment

Just not enough hours in the day right now..... progress has been reduced to a snails pace, but the build is finally getting somewhere.

Since last itme, the spoilers were built as per plan, balsa TE stock and 1/64" ply. Once the linkage was sorted out, the next task was to set up the wing joiners. Immediately a mistake in my construction revealed itself. The ply root plate on the fuselage had to be shimmed out so they were flush, i.e there is a fairing at the wing trailing edge root on the fuselage. This isin't immediatley obvious on the plan, but is once you try to put wings on! So I own up to the mistake, on the basis that I probably won't be the only person to make it! Photo below shows area refered to.

Wing root fairing

The key to this part is to make sure everything is set up squarely and the wings are at the same incidence! Thus, a good incidence meter is well worth having at this point! The fuselage joiner tubes were then epoxied in place along with the rear joiner tubes in the wing, being left overnight to cure.

Wing-fuse join

Following on from this, the remaining upper sheeting and sparcaps were fitted to the wing, the ply root ribs, blase leading edges and balsa tips were fitted. The aileron was fitted with a leading edge "cap" as shown below. This is NOT clear on the plan, however it is used in the construction article that Aviation Modeller published for this plan. This was shimmed from the wing trailing edge by 1/16" scrap balsa to allow for the aileron leading edge sheeting, which is fitted after the ailerons are cut out.

Leading edge cap

The ailerons were cut out carefully from the wing, bevelled to allow hinging motion and the aileron leading edge fitted. The canopy frame was made from laminations of basswood around the former that comes with the kit. The molded canopy was then fixed to this using catalysed PVA which dries clear. The nose block was fitted and sanded to shape. At this stage I had to see the whole thing assembled:

Test Assembly

This is shaping up to be a lovely model. The wings are now done bar covering. The fuselage still needs the rear canopy part (I'm modelling a prototype with no rear transparency), and the pushrods and servos for the tail need to be installed. Then we'll be ready for covering! Until again....

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