WF – XL 

BUILDING INSTRUCTIONS 

(Spoileron Version) 

By Frank Wren 

 

PREFACE 

 

The plans for this model have been drawn for RES class (Rudder, Elevator and Spoiler control) plus Optional Flaps and Ailerons. Determine which way you want to build the model before starting construction. Review the plans and note that there are additional instructions and ‘tips’ noted on the plans that apply to the construction of various parts of the model that you will need to follow. Also, consult the construction photos accompanying these building instructions or see them in color on the WEB at www.skybench.com .

This set of instructions was specifically written to build this model with Spoilerons .

 

 

HORIZONTAL STABILIZER 

 

  1. Fasten H. Stabilizer (stab.) section of plans to building board and cover with waxed paper. 

  2. Select one laser cut spar, a root rib and a tip rib from the stabilizer parts bag. 

  3. Lay the spar and ribs (in exact position) on the plans for the left stab. Tape the spar to the plan in several places with masking tape to temporarily hold it in the exact position. Do not stick pins through the spar!

    CA thin
  4. Using the plan as a guide, place the root rib spar notch in position on the spar and glue with instant CA. 

  5. Repeat the above instruction for the tip rib. 

  6. Remove the partial assembly from the board and set aside. 

  7. Repeat instructions #2 through #6 for the right stab.

  8. Select one balsa trailing edge sheet and pin it in position on the left stab. plan. Be sure to trim it to the plan’s dimensions first, if needed.

  9. Select one balsa leading edge sheet and pin it in position on the left stab. plan, trimming to size as needed. Select the left side spar/rib sub-assembly completed above and align the bottom rib notches of the root and tip ribs to the rear edge of the leading edge sheet and glue with a drop of instant CA where the ribs touch the trailing edge of the sheet. The spar should be resting on top of the sheet and in its proper position so glue it to the bottom leading edge sheeting with instant CA. the full length of the spar.

  10. Reposition the pins holding down the leading edge sheeting to the front edge of the spar. Slip a piece of very light cardboard (like a 3x5" index card) between the waxed paper and the plan at the root rib location. Gently raise the cardboard until the sheeting touches the root rib, then glue with instant CA. Repeat this procedure at the tip rib.

  11. Gently push the root rib and tip rib trailing edges down to meet the trailing edge sheet, making sure the rib notches are touching the front edge of the sheet and the root and tip ribs are flat against the top of the sheet. If not, reposition the trailing edge sheet until it does. Glue root and tip ribs to front and top of the sheeting with instant CA. 

  12. Install the remaining 4 ribs and glue to their proper locations with instant CA. Use the cardboard technique above on the front of the remaining ribs. The trailing edge sheeting should fit the notches on the rear bottom of the ribs. If not, trim rib notch as needed, then glue with thin CA. 

  13. Cut the vertical shear webs from the supplied 1/16th inch thick balsa sheeting. The shear webs are glued to the center of the bottom spar and the sides of the ribs between each rib bay, except for the root bay where the joiner tubes are located.

  14. Cut the root rib gusset from scrap balsa and glue (CA) it to the trailing edge at the tail if the root rib. 

  15. Wing trailing edge detail
  16. Sand a taper to the rear of the trailing edge sheet, starting at the ends of the Ribs (see taper line on plan). 

  17. Glue top spar to ribs and shear webs using ‘Thick’ (slow cure) CA. Be sure spar fits flush all the way from the root rib to the tip rib before gluing as the spar MUST make total contact to the shear webs and ribs in order to maintain its strength. 

  18. Repeat steps #8 through #17 above for the right stab.

  19. Insert a set of joiner tubes through the root rib to the 2nd rib in the left stab. (Be sure the 1/16th & 3/32nd diameter joiner wires will slip freely into the tubes. You may have to trim out the tube opening with the point of your hobby knife). Then insert the wires in the tubes and pin the left stab. half over the left stab. plan. Next, slide the stab control horn over the joiner wires. Then insert the second set of joiner tubes into the right stab. half and slide this stab. half onto the joiner wires. Align the stab. halves to each other and tack glue (use instant CA) the tubes in place. Separate the stab. halves, remove the wires and permanently glue (use ‘thick’ slow cure CA) the tubes.

  20. Attach the top sheeting to each stab. half (one at a time) using slow cure CA on the spar and ribs. Set the rear edge of the sheeting against the notch in the ribs and push the sheeting down over the rib tops and hold till CA cures (about 15 seconds). Be sure to slip a waxed paper covered support stick under the front edge of the stab.

  21. Attach top trailing edge sheeting to each stab. half using slow cure CA.

  22. Sand the leading edge sheeting (on both stabs.) flush with the face of the ribs. Use a sanding block and keep the root-to-tip line straight. 

  23. Glue the 1/8th x 3/16th balsa leading edges in place on both stabs. with CA to the rib fronts and the edges of the sheeting. Trim off any excess at root & tip.

  24. Slip the 1/16th plywood root cap over the protruding joiner wire tubes on each stab. to check for flushness...when fit is flush, glue to root rib with CA. File any excess joiner tubes flush with the plywood root cap.

  25. Install tip blocks after checking to be sure they are flush with the stab. tip. Use slow cure CA. 

  26. Sand leading edges, trailing edges and tip blocks to shape. Use the plywood root cap as a guide for the leading edge shape.  

 

VERTICLE STABILIZER (FIN) and RUDDER 

 

      1.   Retrieve the balsa fin, balsa fin extension, the 2 plywood fin doublers, the stabilizer bell crank (2 Pieces), the aluminum pivot wire tube, the 2 stab. fairings, clevis and 1 wire pushrod from the kit.

      2.   Line up the balsa fin on the waxed paper covered plan and pin to building board. Position the fin extension in place at the front of the fin and join to the fin with instant CA. Remove assembly from the board.

      3.        Glue (use Model Airplane glue) the right side plywood fin doubler (the one without the pushrod slot near the bottom) to the right side of the fin in the exact location shown on the plans. (NOTE: Bevel the top and front edge of the fin doublers prior to gluing). Be sure the aluminum pivot wire tube will slide snuggly through its hole in the plywood doubler and that the stab. pivot wire will slide through the tube (you may have to use the point of your knife blade to clear any internal burrs from both ends of the tube).

      4.   Select the 2 stab. Bell crank pieces and cut off the bottom 1/4th of the long arm of 1 piece (see photo), then glue the 2 pieces together (CA). Caution: make sure the holes in the top part of the bell crank are perfectly aligned and that the aluminum tube slips smoothly (not sloppily) through its hole.  

      5.   Solder the clevis connector to the end of the wire pushrod and connect the clevis to the bottom of the bell crank.

      6.   Insert the aluminum tube through the right side plywood fin doubler (already glued to the fin base), then slip the bell crank (with attached push rod) onto the tube from the opposite end. After applying glue (Model Airplane glue) to the fin area to be covered by the left side fin doubler, then slide the left side plywood fin doubler over the tube and onto the fin. Caution: this is the critical part of this procedure. Before the glue begins to dry, make sure the tube is perfectly aligned 90 degrees top & bottom and front & rear to the vertical plane of the fin. Make corrections by moving the left side plywood doubler up/down and/or front/rear. When the glue has dried, stand the fin vertically and apply a drop of instant CA to the area where the pivot tube exits the plywood doublers on each side of the fin. You must have the fin standing vertically when applying the drop of instant CA in order to keep the glue from wicking down the tube and gluing the bell crank to the tube.

      NOTE: The aluminum tube should stick out equally past the sides of each plywood doubler as the Stab. Fairings will be attached to the tube...do not cut the tube off flat with the sides of the fin.

Stab fairing detail
      7.   Slide the stab fairings over the pivot tube and onto the fin (position 'dead center' as noted on the plans) and glue with instant CA around the edges of the fairings. Then complete by (a.) cutting the fairing away from the slot to be used by the stab. alignment wire, (b.) cut off the rear of the fairing flush with the rear of the fin and (c.) file away any of the tube that may be protruding beyond the fairing.

      8.   Set this sub-assembly aside until it is needed during the fuselage assembly.

      9.   Pull the two balsa rudder pieces and the two triangular plywood doublers from the kit.

     10.  Align and pin the rudder and rudder base over the rudder section of the plans (don't forget to cover plans with waxed paper) and glue together with instant CA.

     11.  Bevel the edges of the thin plywood doublers, and then precisely align the doublers over the holes in the base and glue (CA) into position on each side of the rudder.

Rudder taper detail
     12.  Using a sanding block, sand a tapered shape (from front to rear) to the rudder. Do not make the trailing edge too thin. (see photo). After tapering the rudder, round the edges of the rudder using your sanding block with "fine" sandpaper.

     13.  Cover with your preferred covering material.

     14.  Install the rudder Control Horn.

 

WINGS 

 

      1.   Select the 4 spruce 3/8" x 36" sticks and the 4 spruce 3/8" x 24" sticks for splicing together. You have the option of using the supplied balsa 3/8" x 24" sticks instead of the spruce ones in order to reduce tip panel weight (recommended option). Cut the splice at the angle noted on the plans for each of the sticks. Trial-fit each piece to be certain that when fitted together the spar will be straight on its leading edge. Correct angle if needed.

      2.   Taper the back edge of the 3/8"x 24" spar pieces; beginning at the location noted on the plans and ending at the tip (see plans).

      3.   Glue (epoxy) the short spar pieces to the long spar pieces, being sure to keep the pieces straight by laying a straight edge against the front edge of the spar at the splice joint. DO NOT stick pins through the spar material. Be sure you make 2 left wing and 2 right wing spars, each with the tip spar piece tapered on the back edge. TIP: It helps to mark each spar "left bottom, left top, rt. bottom & rt. top".

      4.   Optional step: You can glue (slow-cure epoxy) 0.007 carbon fiber strips to the bottom of the bottom spar and the top of the top spar to gain extra spar strength. You can purchase 3/8" wide carbon fiber strips from your local hobby shop. If building the wing with flaps, flaperons or spoilerons, it is recommended that the carbon fiber be used from the wing root out to a point just past the spar splice (36 inches).

      5.   Begin wing construction by fastening the LEFT wing plan to your building board (allowing you to have the Right wing plan available for reference during the Left wing construction). Before covering left wing plan with waxed paper, use a fine tip marker and extend the lines on the plans for the spar location at the root and the tip as well as the location for each rib (extend the rib location lines at both the leading edge and the trailing edge). These lines will serve as location guides when the plans are covered by the bottom sheeting during construction.

Sheeting splice detail
      6.   Select 2 leading edge 1/16th balsa sheets and splice (glue with CA) together over the waxed paper covered plans. Cut a 'splice doubler’ from 1/16th balsa sheet and glue in position. Use the trailing edge of the sheets to position on the plans and pin to the building board. Before splicing, make sure the trailing edges of the sheets are straight. If not, use a straight edge and trim with modeling knife.

      7.   Select the 1/16th balsa sheet for the wing center sheeting and trim to size per the plan. Glue (CA) in position against the back edge of the front sheeting and pin to building board.

      8.   Select the 2 trailing edge 1/16th balsa sheets. Note that the tip sheet has to interlock with the root piece between ribs #16 & #17 so cut the root sheet to accept the tip piece. When fit is accurate (per plans), then glue (CA) and pin in position over the plans. Then cut and glue (CA) the 1/16th balsa sheet insert to the end of the root trailing edge sheet and tip trailing edge sheet.

      9.   Cut and glue (CA) the 1/16th balsa rib Cap Strips in place between the leading edge and trailing edge sheets from rib position #9 through #25.

      10. Take a straight edge and fine point marker and mark the rib positions onto the bottom wing sheeting.

      11. Select the wing spar you have marked as “left bottom” and position it on the leading edge sheeting using the spar extension lines drawn earlier. Check to make sure the spar runs straight between the wing root and the tip. Use a straight edge along the spar edge to check and correct as needed. When straight, glue (CA both edges) in place on the sheeting. NOTE: If spar has had carbon fiber strip added, be sure the carbon fiber side of the spar is face down to the sheeting before gluing.

Left wing with spoileron
      12. Select 1 of the balsa sticks to be used as the hinge point facing for the spoileron and glue (CA) into position on the trailing edge sheeting from wing root to the inside edge of rib #17 location.

      13. Select wing ribs #1 through #16.

            (NOTE: drill out the 'servo wire' holes in ribs #1 - #5 to accept the diameter of the soda straw to be used for the 'servo wire' tube)

Rib ends detail
            Each rib will have to have the tail end cut off 90 degrees to the rib bottom to allow the rib to fit snuggly between the spar and the spoileron hinge point facing stick installed in #12 above. Measure the distance between the spar trailing edge and the hinge point facing stick for each rib and cut off the rib tail accordingly. Be sure to number the cut-off piece and save it in a small box or bag for use later.

            NOTE: be sure to make copies of the rib tail pieces of ribs #5 and #15 for the spoileron. These are used at each end of the spoileron.

            Trial fit the modified ribs to their proper locations and glue (thin CA) to the spar and back to the facing stick (butt joint). Don't glue rib #1 yet...it will be installed later. Don't glue ribs to front sheeting yet.  Next, trial-fit ribs #17 through #25 and glue (CA) into position.

      14. Reposition any pins used to hold down the front bottom sheeting to just in front of the wing spar. Loosen the waxed paper from the plan and slip a piece of stiff card stock (3x5 index card, playing card, etc.) between the plans and waxed paper. Lift the front edge of the piece of card stock under one of the ribs until the bottom sheeting touches it fully, then glue rib to sheeting with thin CA. Do this for each rib. When finished, remove card and re-fasten the waxed paper.

      15. Stick a series of T-pins vertically along the back edge of the spoileron hinge point facing, starting at the rib #15 location to the rib #5 location. The pins will create a hinge line gap for the spoileron.

            NOTE: the spoilerons do not extend all the way to the wing root. When the pins are all perfectly vertical and flat against the hinge point facing, glue (CA) into position the spoileron leading edge facing stick. NOTE: the spoileron facing stick starts at rib #5.

      16. Retrieve your container of cut-off rib ends. Measure the distance used by the hinge point facing and spoileron facing sticks at each rib position and cut off the front of the corresponding rib tail 90 degrees to the rib bottom and glue (CA) each shortened rib tail in place on the trailing edge sheet and against the back edge of the spoileron facing stick.      

      17. Use a razor plane and sandpaper to trim and shape the hinge point facing and spoileron facing sticks down to match the rib airfoil of each rib, being careful to not cut into the ribs.

      18. Sand a bevel to the trailing edge sheeting (as noted on the plans).

      19. Cut to size the 3/8" thick shear webs to fit between ribs #3 through #9 and ribs #16-17 (the area of the spar splice). Be sure each end matches the height of the upper spar notch of the ribs on each end of the shear web. Use a 3/8th inch wide sanding stick (see photo for simple instructions to construct this tool) to accomplish this task. Use the top spar to check that it is flush with the top of the vertical shear webs without any gaps. When correctly sized, glue (aliphatic resin wood glue) each web in place, making sure each web is centered exactly on the 3/8"wide spar. Then glue (aliphatic resin wood glue) the top spar in place, making sure the spar is perfectly seated on the shear webs and in the rib notches without any gaps. If spar has a carbon fiber strip added, the carbon fiber should be facing upward.  [ Run a bead of wood glue on top of the 3/8 th inch shear webs and spread evenly across the top of each shear web with your little finger to make a good bond for the spar ]. Also make sure the root end of the spar is even with the root edge of the wing. Wipe any excess glue away from the spars and shear webs. Add some weight to the top spar to hold it in contact with the shear webs while the glue dries.

      20. Select two1/64th thick plywood shear webs from the kit and trial-fit between ribs #16-#17 (the spar splice area). When properly sized, glue (epoxy) one to the front edges of the spars and 3/8th inch shear web and one to the rear edges of the spar and 3/8th inch shear web.

      21. Trim to size the 1/16th balsa vertical grain shear webs to fit along the front & rear of the spars from rib #17 to #25. When properly sized, glue (CA or aliphatic resin wood glue. CA is much lighter.) in place against the front and rear of the spars. Be sure the shear webs touch the rib on each end of the shear web. If using aliphatic resin wood glue, be sure to clamp the shear webs to the spars (use the old fashion wooden, spring loaded clothes pins) while the glue is drying (over night).

      22. Trim to size the 1/16th balsa vertical grain shear webs to fit along the front of the spars from rib #9 to #16 and along the rear of the spars from rib #8 to #16. When properly sized, glue (aliphatic resin wood glue) the shear webs in place along the front and rear of the spars. Clamp shear webs to spars while the glue is drying (over night).

      23. Un-pin the wing panel from the building board and raise the wing 1 and 5/16ths inch at the tip rib (#25). Station 2 t-pins vertically at the wing root, 1 at the upper leading edge and 1 at the trailing edge. Cut the tail off of rib #1 (90 degrees to the rib bottom) so it fits snuggly between the spars and the spoileron hinge point facing stick. Use a 90 degree triangle (or a squared block with a 90 degree angle) and gently push rib #1 in its proper location on the wing and against the triangle until it touches the triangle. Use several 'drops' of CA glue at several points along the rib bottom to glue it to the spar, sheeting and hinge point facing stick (Place a piece of waxed paper between the triangle and the rib before using the CA). This makes rib #1 match the dihedral angle of the wing and allows the wing root to fit flush against the fuse side when the wing is mounted to the fuse. Cut off an amount of the front rib tail to compensate for the facing stick thickness and set its angle as noted above and glue (CA) in position.

      24. Installation of the front plywood shear web (SWF 1):

                          Read all of the information in this instruction first before beginning the process!

            Pin the wing to the building board at the trailing edge and the rear of the wing spar. Then slip a balsa stick (span wise) under the front sheeting (and the waxed paper) until it touches the sheeting and supports the leading edge of the wing. Pin all the way through the sheeting and support stick to the board. Use a 'razor saw' to cut wing ribs #2 through #8 free from the front of the spar at the point where each rib joins the front of the spar. Caution: do not cut rib #1. The cut must be vertical starting at the top edge of the top spar all the way down to the bottom edge of the bottom spar. After making the cut, use an 'emory board' (thin, stiff sand-paper like boards women use to shape their finger nails...you can buy a pack at the drug store or Wal-mart) to open up the cuts just wide enough for the plywood shear web to fit snuggly between the spar and the ribs. Remember, you want the plywood shear web to be touching both spar edges and all of the rib backs so take your time with the emory board and trial-fit the SWF1 piece frequently. NOTE: the root end of the SWF 1 piece must fit against the side of rib #1 and since rib #1 has a slight angle on it, you will have to sand the root end of SWF 1 slightly to match the angle of the rib. When the SWF 1 piece fits perfectly all the way down to the sheeting, spread a thin coat of slow-cure Epoxy to the back of SWF 1 as well as the front edges of the spars and 3/8" balsa shear webs and slide the SWF 1 piece in place. Make sure SWF 1 is pushed all the way down to the sheeting and is flat against the front edges of both spars. Clamp the SWF 1 piece to the spar all along its length to insure a complete bond. Don't release the clamps or the wing from the board until the epoxy has completely cured (allow at least 24 hours for epoxy to fully cure).

 

            The next step will be the installation of the wing joiner brass tubes but this step cannot be done until the other (right) wing panel has been completed to this point . Set the above (left) wing panel aside and build the right wing panel following steps 1 through 24 above. When the right wing panel is constructed through step #24 above, then proceed to step #25 below.

 

Joiner tube preparation
      25. Wing Joiner Brass Tube Preparation:

        File each end smooth and even to remove any jagged edges.

        Sand external surface of each tube with medium grit sandpaper to scratch up the surface thus allowing

           the epoxy to effectively bond to the tubes surface.

        Use a model knife with a pointed #11 blade to cut a bevel to the inside edge of one end of each tube.

        Press the beveled end of each tube through a piece of scrap 1/16 th balsa to plug the end.

        Use 'thin' CA around the tubes lip to glue the plug in place.

        Rub down each tube with alcohol to clean it of any oil.

     26. Cut a piece of 3/16th to 1/8th inch thick balsa sheet the exact width of the fuselage (including the thickness of the 2 plywood wing fairings) and as long as the wing root. This spacer board must have each side parallel to each other to provide proper alignment of the wings when they are attached to the fuselage sides. Pin the spacer board to your building board (see photo).

Joiner tube joining
      27. Insert a brass tube (plugged end first) through the large hole in rib #1 for each wing and then insert the wing rod into each brass tube. Position the wing roots on each side of the spacer board and pin the wing roots to the building board to hold them in place. Raise each wing tip (at rib #25) 1 and 5/16th inch above the surface of the building board. You may have to slide the brass tubes out of the wing a bit to get the desired tip elevation. When the proper elevation is reached, tack-glue the brass tubes in place to hold them in position while you 'gently' release the wing from the building board and separate them from the wing rod.

      28. Prop one wing up on its leading edge 90 degrees to the building board and level at the spar area. Mix a batch of slow-cure epoxy sufficient enough to fill the cavity around the brass tube. Pour the epoxy into the brass tube cavity, making sure the epoxy completely fills the area between the top & bottom spars and from rib #1 to rib #3. Do not allow the epoxy to rise above the edges of the spars. Remove any excess epoxy before it starts to cure.

      29. Repeat above step #28 on the other wing and let epoxy fully cure.

      30. Glue (epoxy) the screw-eye base hardwood blocks in place (per plans) to the inside of rib #1.

Various wing tubes
      31. Cut two (2) alignment tube supports from a 1/8th x 3/8th " stick to fit between ribs #1 & #2 (see plan).

      32.  Slide the wings back onto the wing joiner rod and insert the aluminum wing alignment tubes into the wing roots and insert the alignment wire into the tubes. Set the wing assembly back over the spacer board, flush with the sides of the board and pin the wing roots to the building board at rib #1. Raise the wing tips 1 and 5/16 inches. Position the tubes so the alignment wire isn’t binding in the tubes. Tack glue (thick CA) to the root rib and rib #2. Position the alignment tube supports in place behind and against the tubes and glue (thick CA) in place. When glue has cured, unpin the wings and remove the wing rod and alignment wire.

      33. Insert the soda straws used for the servo wire tubes through ribs #1 - #5 and glue with thick CA.

      34. Cut the spoilerons free from the wing and set aside.

Spoileron servo hatch
Spoileron servo detail
      35. Cut out the spoileron Servo Hatch in each wing between rib #5 and #6. The hatch has to be far enough forward to keep the rear of the servo case from sticking up above the ribs. Use several 1/8th square balsa sticks cut to length to make a frame-work to hold the servo in place on the servo hatch (see photo). Use Silicone glue to hold the servo to the hatch.

      36. Pin left wing to building board and using the procedure listed in step #24, install the rear plywood shear web (SWR 2). Do same for the Right wing.

      37. Install additional plywood shear webs (SWR 3-4) between ribs #2 - #4 using same procedure used above for both wings.

Top sheeting work
      38. Reposition Left wing over the plans (covered with waxed paper) and install the leading edge sheeting. Use slow-cure epoxy on the portion of the spar that has carbon fiber strip. Use Aliphatic Resin Wood glue on remainder of the spar and the tops of the ribs. Place thick phone books (soft cover type) over the wing sheeting to hold the sheeting in contact with the spar and ribs until the glue dries.

            NOTE: Be sure the leading edge of the wing is supported before you use the phone books! Allow the glue to dry overnight.

      39. Install the center and trailing edge sheeting. Use wood glue where the sheeting fits over the ribs and thin CA where the center sheeting touches the leading edge and the trailing edge sheeting. Install the balsa wood cap strips over the top of ribs #9 through #25.

      40. Sheet the Right wing as outlined in steps 38 & 39 above.

      41. Cut away the sheeting covering the spoileron opening on the trailing edge of the wings. Sand sheeting even with the root and tip ribs.

      42. Sand front sheeting evenly down to the front ends of the ribs using a long, flat sanding block.

      43. Splice the Leading Edge balsa sticks together and taper the tip ends as noted on plans.

Leading edge attachment
      44. Apply wood glue to the front ends of the ribs and install the leading edge stick. Hold the leading edge stick in position on the wings with strips of masking tape till the glue dries. Make sure the top and bottom leading edge sheeting is flush against the leading edge stick. The edge of the sheeting can be glued to the leading edge stick using thin CA. (see photo).

      45. Sand ends of leading edge sticks flush with the root and tip ribs.

      46. Glue (epoxy) the plywood Wing Root Cap to the wing roots. Make sure the end of the servo wire tube is not covered over. If you did not drill the servo wire hole earlier to match the servo wire tubes diameter, do it now before gluing the root caps to the wing roots.

      47. Shape the leading edges using a razor plane and a sanding block. Use the plywood root cap as a guide and consult enclosed photo.

Leading edge and tip shaping
      48. Attach tip blocks to the wings with thick CA and sand to shape (see plans and photo).

Spoileron with control horn mouting blocks
      49. Fabricate the Control Horn Mounting Blocks for the spoilerons (see photo). Cut slot the same width as the control horns thickness (the control horns are installed after the spoilerons have been covered with your favorite covering material). Install the top sheeting. Sand the edges of the sheeting flush on the ends and sides. Sand a bevel to the leading edge of the spoilerons from the top edge of the top sheeting angling down and back about 20 degrees to the bottom sheeting.

 

 

FUSELAGE 

 

Fuse sides
      1.   Locate the balsa fuselage sides (each side consists of 2 parts, a front half & a rear half.). Glue the 2 halves together (with CA) for each fuse side after making sure the bottom edges of each piece at the glue joint is straight by setting the bottom edges of both fuse pieces against the top edge of a yard stick. [NOTE: The left fuse side is the one with the horizontal slot near the rear end of the laser cut sheet. The slot is for the rudder push rod.

      2.   Select the 1/64th Plywood fuselage doublers and glue (using slow cure epoxy) in place on the inside of each fuse side. Be sure the holes in the front doublers and the slot in the left side rear doubler exactly match the corresponding holes/slot in the balsa sides. After the doublers are glued, cover with waxed paper and place weights (books, etc) on top of the fuse sides until the epoxy has cured.    

            CAUTION: remember you are building 2 fuse sides. The Left side is the side with the rudder push rod slot. Glue the doubler with the slot to the fuse side that also has a slot and make sure you are gluing it to the inside of the fuse half (otherwise, you will end up with 2 fuse pieces configured for the same side!).

            TIP...After applying the epoxy to each doubler, use a thin piece of plastic (credit card size) or stiff cardboard and squeegee off the excess epoxy so only a very thin layer of epoxy is left. This will greatly reduce the weight of the glue.

      3.   Place the right fuse side on the plan and mark the locations for the formers and 3/16th  square balsa uprights onto the inside of the fuse side. Also mark the left fuse side.

      4.   Attach the plywood F2 piece in place on the right side fuse half using slow cure CA. Also attach the F3 balsa piece. Make sure F2 & F3 pieces are aligned exactly as noted on the plans before gluing.

      5.   Measure and cut to length the 3/16th square longerons and glue (CA) in place at the top and bottom of the fuse side, making sure the outer edge of each longeron is flush with the edge of the fuse side.

      6.   Attach the plywood formers F1, F1A and F5 to their respective positions with slow cure epoxy. Make certain the formers are 90 degrees to the surface of the fuse side (best done using a 90 degree triangle).

      7.   Cut to size the 3/16th square balsa uprights and install between the longerons at the positions noted on the plans (use instant CA).

      8.   Repeat steps #4, 5 and #7 for the left side fuse half.

      9.   Taper the 3/16th square longerons at the fin base.

      10. Trial fit the left fuse side to the right fuse side and make sure the fit is correct and both sides are square to each other and not twisted or misaligned. Make any necessary adjustments. When all is square, epoxy the left fuse side to the right fuse side at formers F1, F1A and F5.

11. Select the short length of yellow tubing from the kit. Cut off 10 pieces 1/4th inch long. Set these aside for use several steps later. They will be used as push rod guides and will be glued to the five 3/16th uprights on each side of the fuse. Do not glue them in yet!

Stab fitting detail
12. Trial fit the Fin assembly between the fuse sides by pulling the rear ends of the fuse sides up to the fin. If the tapered longerons are correct, the end of the fuse on both sides should close flush against the fin. If not, add more taper to the longerons until the fin mates with the fuse sides. Make sure the fin sits straight up (90 degrees to the fuse). If not, make necessary corrections as the fin must be vertical.

      13. Slip 4 of the yellow push rod guide tubes (cut to length in step 11 above) onto the stabilizer push rod and insert the push rod into the push rod hole on the left fuse side of former F5, then slip the 5th yellow push rod guide onto the push rod and continue feeding the push rod through former F1A and F1. Position the fin in its proper position (according to the plans), then apply a thin coat of epoxy to the longerons in the area where they will contact the fin sides. Stand the fuse upright on a flat surface and bow the 2 fuse sides together until they mate with the fin and clamp them to the fin. Make any alignment corrections before the epoxy cures.

Push rod quide detail
      14. Insert the Rudder push rod into the rudder push rod slot at the rear of the left fuse. Carefully guide it so that it also passes through the slot in the fin doubler. When the push rod has cleared the fin, slip 4 of the push rod guides onto the push rod and feed the rod through the push rod hole on the right fuse side of former F5, then slip the 5th guide onto the rod and continue feeding it through former F1A and F1.

      15. Insert the antenna tube through the antenna tube holes in formers F1, F1A and F5 and glue (CA) the antenna tube in place. You can make the antenna tube from soda straws (not supplied).

      Nose detail detail
16. Epoxy the nose block between the front fuse sides. Be sure the rear of the block butts up against F2 & F3. TIP: Drill a ½ inch hole 1 inch deep in the center of the block before installing. This hole can be used to add additional nose weight should it be needed to balance the model.

      17. Cut to length the 3/16th square balsa cross frame members and glue (CA) in place both top and bottom of fuse (check plans for locations). Don't forget the bottom one between the nose block and former F1.

      Hatch alignment detail
18. Cut 2 Hatch Alignment Tabs to fit between the F2 plywood pieces. Mount the Hatch Block to the fuse (sand ends as needed) and turn the fuse upside down and glue the tabs to the hatch block. Do not glue the tabs to the sides of the fuse.  Remove the block and slightly bevel the ends of the tabs to make the block seat easily on the F2 edges. Set the block aside until later when shaping the nose block.

      19. Glue (epoxy) the Servo Tray to the bottom rear sides of the F2 pieces and against the F1 former. Be sure you have removed the rear-end piece of the servo tray as it will be used as the tow hook base.

      20. Glue (CA) the front Anti-Crush Block to the rear of former F1 and the rear Anti-Crush Block to the front of former F5.

            NOTE: The blocks fit under the top longeron and run the full width of each former.

      21. Ballast Tube Option: See instructions printed at the bottom right-hand side of the plans.

      22. Glue (CA) the rear balsa bottom sheeting in place.

      23. Gently form the curve to the 1/8th inch light plywood front bottom sheeting and epoxy to the bottom front fuse and rear portion of the nose block. (See plans for location).

      24. Epoxy the tow hook mount to the tow hook base, then epoxy the mounting assembly in place (see plans for location).

Wing tubes in the fuse
      25. Slip the fuselage wing rod tube (brass) and the wing alignment tube (aluminum) through their respective holes in the fuselage (they need to be perpendicular to the sides of the fuselage for the wings to fit squarely to the fuselage). Slip the wing rod and wing alignment pin into the tubes and temporarily attach the fuselage wing fairings on the tubes on each side of the fuselage. Slide the wings onto the rod and alignment pin. They should slide on smoothly and fit flush against the fuselage wing fairings. If they do fit squarely, then apply a small amount of epoxy to the tubes at the point inside the fuse where they touch the fuselage to ‘tack’ the tubes in position. When the epoxy has cured, carefully remove the wings, rods and fairings and apply a generous amount of slow cure epoxy to the tubes all around the area inside the fuselage where they touch the fuselage (see photos).

            If the wings do not fit squarely, carefully modify the fuselage tube holes until the wings fit right, and then finalize the tube installation as noted above.

Leading edge attachment
      26. Locate the Balsa wood fuselage top sheeting and trial fit it to the fuselage. Draw a rectangle at a position 3/8th inch rearward of the wing rod brass tube and no wider than the width between the fuselage side longerons. Make the rectangle about 2 to 2 1/2 inches long. This will be the access hatch opening used to make servo wire connections. Cut out the rectangle (use modeling knife and straight edge) and keep the rectangle...it becomes the hatch cover (see photos). Turn the fuselage top sheet over and glue 2 pieces of 1/16th thick x 1/4th inch wide balsa strips at the top & bottom of the opening at the narrow ends. Make sure the strips are no wider than the width of the opening. Allow 1/3 of the strips width to over-hang the opening. These will form the 'lip' edge to hold the hatch lid in place. The lid will be held in place with tape after the model is completed. Turn the fuselage top over, reposition on fuselage and if everything fits, glue (wood glue or CA) sheeting to fuselage.

      27. Glue (epoxy) the plywood fuselage wing fairings in place on the fuse. When the epoxy has cured, file the brass and aluminum tubes flush with the sides of the fairings. Be sure to use the point of your modeling knife to remove any burrs from the inside lip of the tubes.

      28. At the point where the wing servo connector exit meets the fuselage fairing, drill 2 holes (side by side) into each fuselage wing fairing to the inside of the fuselage. The drill bit should be of a diameter equal to the thickness of the female servo connector. Then use a small round or oval file to blend the 2 holes into a slot capable of allowing the servo connector to pass through the fuselage side (see photo).

Nose shaping
      29. Sand bass wood nose block and radio compartment hatch to shape (see photo) and round the fuselage edges.

 

FINISHING 

Completed Components

Completed Components, closer view
      1.   Final shape any areas not already shaped and give components a final light sanding with 'fine' sandpaper.

      2.   Cover all components with your favorite Mylar covering material using a color you can see easily in the sky.

      3.   Install the control horns in the spoilerons with epoxy.

      4.   Attach the spoileron servos to the servo hatches (silicone glue) and run the servo extension wires through the wing roots. Attach servo hatches to the wings and fasten with tape or several drops of CA.

      5.   Install radio gear (servos, receiver, battery, etc) in fuselage and make push rod connections.

      6.   Hinge Rudder and Spoilerons, and then connect to servo pushrods.

      7.   Attach screw eyes to wing roots and install tow hook.

      8.   Balance model at the desired C/G.

      9.   Charge batteries and check that all controls work properly.

      10. GO FLY!  And enjoy your new model.  


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