The Kavalier was designed as a next-step airplane after a beginning flier has mastered basic R/C flying on the Sig Kadet. The special wing design was developed to aid the novice aileron pilot make smooth, well coordinated turns. Built-in washout (a decrease in wing incidence at the tip as compared to the wing root) helps prevent tip stalls and improves slow speed flight characteristics and landings. Special aileron horns provide for differential action ailerons, with less down movement and more up. On ailerons with equal up and down movement, the increase in drag caused by the lowered aileron is apt to cause an adverse yaw reaction, swinging the nose of the model opposite to the aileron roll direction. The combination of wash out and differential ailerons contribute to the easy handling qualities of the Kavalier.


A Note On Balsa Wood

We do our best to put as good a grade of balsa in our kits as the supply situation permits. The world-wide increase in demand for balsa has made it impossible to obtain as high an average quality as used to be the case and this situation is getting worse.
Every piece of balsa supplied cannot be 100% perfect or kit prices would have to be greatly increased. Mineral stains or small knots do not seriously affect wood strength. Even with the very best grades of balsa, there is a natural tendency for some sticks or sheets to immediately bow upon being cut off from a perfectly square block because of builtin stresses. In most cases, these can be bowed back into alignment during building. True up the edges of bowed sheets by trimming, using a metal straightedge to cut against. Planking sheets, as used on the wing, need not be perfectly flat since they must be curved into place anyway during construction. The gluing of the plywood doublers and stringers to the fuselage sides while they are pinned to a flat surface should flatten out any warps in the side sheets.

Wood Sizes In The Kit

Sometimes, depending on the raw wood supply and sawing schedules, we may put a larger piece of planking wood in the kit. For example, you may get 2" wide wood for the wing trailing edge planking instead of 1-1/2" wide. This extra wood, cut off when planking, can be saved for some other use.
In other cases, the wood may measure slightly larger than the dimension called for on the plan. We feel that it is best to have enough wood when fitting a part in place, so it will adequately fill the spot, instead of an "exact" size that might be not quite big enough, given the tendency of model components to "grow" as the parts are glued together.

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Recommended Glues

The framework may be glued with either Sig-Bond resin type glue or Sig-Ment solvent type cement. In any joint involving plywood or hardwood, Sig-Bond is the best choice. Areas subjected to unusual strain, exposed to fuel or oil, or including metal pieces, should be epoxied with Sig Epoxy Glue or Sig Kwik-Set 5 minute type epoxy. Some specific pieces have other recommendations. You will find these in the directions concerning the part.

About The Building Sequence

The quickest and most efficient way to complete a model is to work on several pieces at the same time. While the glue is drying on one section you can start on or proceed with another part. Work can even go forward on several sections of the same assembly at the same time, such as the front and rear of the fuselage. We occasionally get suggestions that our instruction books should be in exact step-bystep building sequence. But this would result in many sentences starting, "While the glue is drying on the fuselage, move to the wing etc." and a lot of jumping back and forth between assemblies with no consistent pictorial progression. Also, a pre-selected building sequence by our choice might not suit your workshop space and time allotments. Therefore, we feel the present system of covering main assemblies in a unit works out best for the majority of kit builders. So keep in mind that the numbering sequence used in this book was chosen as the best way of explaining the building of each major assembly and is not intended to be followed in exact one-two-three fashion. Start on the wing at No. 1 and after performing a step or two, flip over to the next main heading of "FUSELAGE CONSTRUCTION" and do a step or two there, then over to "FIN ASSEMBLY" and so forth. You will, of course, arrive at points where you can go no farther until another component is available. For example, you need a completed and mounted wing before the front of the fuselage on top can be completed. The way to understand these relationships is to read the book completely and study the full size plan before beginning to work.

Some Rules To Follow
Cut all long pieces of balsa first, followed by medium lengths before cutting up any full-length strips into short pieces. Remove die-cut pieces from the sheets carefully. If difficulty is encountered, do not force the part from the sheet. Use a modeling knife to cut it free. Leave parts in the sheets until needed in construction.

A piece of Celotex-type wallboard makes a handy building board, into which pins can easily be pushed. Lay the building board on a table with a flat and untwisted top. Pins can be pushed through all pieces in the kit without any lasting damage. Don't be afraid to use plenty of pins when planking. The holes will fill up during sanding and doping.
Wax paper should be used to protect the plan during building when the glue used is epoxy or an alphatic resin glue such as Sig-Bond. If a model cement like Sig-Ment is preferred, use plastic wrap to protect the drawing. This type of glue can dissolve the wax, which will inhibit drying.

Be careful where you use a ball point pen for making marks. If not sanded off, these marks will bleed through many coats of dope and show on the finished model.

Any reference to right or left refers to right or left as if seated in the cockpit.

You Can't Get Along Without A Good Sanding Block

An indispensable tool for proper construction is a large sanding block, sized to take a full sheet of sand paper. Use several wood screws along one edge to hold the sheet in place. We recommend 80 grit Garnet paper for use on the block during general construction. You can switch to 100 grit for final finish just before covering

In addition to the large block, there are places where a smaller one is handy.

Also, a sandpaper "file" can be made by gluing sandpaper to a flat spruce stick for working in tight places. We have an especially handy extra long sanding block made from a 40 inch piece of aluminum channel with sandpaper glued to it that is particularly useful for jobs like lining up and beveling ribs prior to gluing the leading edge in place.

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Cutting Out Printed Parts

A jig saw is best for this job. Cut just outside the lines, leaving all of the black line on the part. When fitting the part into place in the model, use the sanding block to bring the edges to an exact fit. If a modeling knife is used to cut out the parts, don't cut too close to the lines, leave some extra wood outside the line. True up and finish the edge with the sanding block.

About Printed Wood Parts

To answer a question we are sometimes asked - no, we do not print parts on wood to save money. It is actually more expensive to print the parts using a silk screen press than it is to run an equivalent sheet through our automatic feed die cutting machine. If we hand-sawed the parts it would be even more expensive and the labor cost would have to be added to the kit price. We believe that most modelers would rather cut their own out and save the cost. Since there are not many thick parts in our average kit, it really doesn't consume a lot of the total building time for the builder to do the parts.

WING CONSTRUCTION

1.

After the ribs are removed from the die-cut sheets, pass the bottom of each rib over a sanding block to smooth and/or level point "X" with the rear jig tab. Only one or two passes should be required, but take care not to oversand. Ignore the other side of the spar hole from point "X", it will not touch the sanding block on the smaller ribs nor is it necessary for it to touch. (See Drawing 7 and Drawing 25).

2.

Check the spar slots in each rib by putting the rib on the spar wood to make certain the slots are deep enough for point "X" to touch the building board. The slot should be wide enough so that the jig tab will rest easily on the building board without having to be forced down. Should the spar slots in the ribs need deepening or widening, file them open a bit with the sandpaper file.

3.

Cut 8-3/8" off the end of each of the 4 pieces of 1/4"x1/2"x36" spar wood provided and glue the pieces to the remainder as center section spar doublers.




4.

Pin two of the spars in place on the plan. Do not glue them together at the center seam.

5.

Glue and pin the ribs in place along the spar. Do not glue Ribs W-l in place, just pin them. Use a small triangle to make certain the ribs are exactly vertical.

6.

Hold the jig tabs firmly to the building board with "T" headed pins.




7.

When all the ribs are in place, add the top spars. Do not glue them together at the center seam or to Ribs W-l.

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8. The place to best check the accuracy of the wing layout is point "Z" as shown on the drawing below. Lay a straight edge along the ribs at "Z". If there are any noticeably high points, touch up these ribs with a sanding block. Do not oversand. Remember the old story of shortening the legs on a table to make it sit level - and the eventual result.

9.

Check the trailing edge supports on the jig tabs with a straightedge and measure the backs of the ribs for correct dimension. Deepen any supports that are too high. Ignore any that are low, the trailing edge will bridge across them.




10.

Use epoxy to glue the 1/4"x1/2" shaped trailing edge to the backs of the ribs only. Do not glue the trailing edge to the jig tab supports.

11.

Pin the trailing edge in place on the supports until the glue sets.

12.

Use a straightedge to cut the leading edge pieces from 3/16"x5/8"x36" strip wood. We don't pre-cut the leading edges because of the tendency of balsa strips to bow after being cut from a square block of wood because of internal stresses in the wood. By trimming them yourself you can cut off the bow. A small point, but one of a number we feel help insure construction of an accurate wing.





13.

Bevel the fronts of the ribs with a sanding block so that they are all in line (check with a straightedge) and will fit snugly against the leading edge.

14.

Lay the straightedge along point "Y" and touch up any extreme high spots.



15.

Pin and glue the leading edge piece in place.

16.

Touch up the trailing edge with the small block.

17.

Touch up the ribs with the large block. Do not oversand.

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18. Epoxy glue is recommended for applying the trailing edge planking for two reasons: First, when set, it will lock the trailing edge in the proper wash-out twist position. Secondly, it will have no tendency to bow or warp as such a large area application might do with water base glues. Photo shows an application of Kwik-Set glue with a Sig Throwaway Epoxy Brush. Work quickly, for Kwik-Set begins to harden in 4 minutes at normal room temperature.




19.

Pin the 1-1/2" trailing edge planking sheet in place.

20.

Shave or carve the leading edge to rough contour shape, using a whittling knife or razor plane. Finish with a sanding block.

21.

  1. Remove one wing half from the board, leaving half there.
  2. Push back Rib W-1 a bit to get it out of the way.
  3. Using the dihedral gauge, mark and trim off the spars, leading edge and trailing edge for the angled dihedral joint.





RIGHT! This is not the "STANDARD" method of wing construction, but there is a reason.

The most common method of assembling a built up wing involves gluing all of the top planking and cap strips on while the wing structure is still pinned to the board. But we noticed that this causes a certain amount of bowing because of the great difference between all of the parts glued to the top without anything on the bottom. Another wing put together in a different way showed no sign of this problem. So the recommended procedure shown in the photos may not be familiar but it will help to improve the accuracy of the special Kavalier wing design. You will find that the sequence shown does not require much extra effort on the part of the builder. On the other hand, if you prefer the standard method, it will produce a wing of acceptable tolerance, if not as good as the sequence pictured. (In this case, use non-water base glue.)

IMPORTANT: Repeat the steps above on the other half of the wing, so that it will be angled the same amount.

22.

Pin a 2-3/4" high scrap block to the board at the end of the wing plan. Draw vertical lines with a 90 degree triangle from the spar location to the top of the block.

23.

Return the wing half that had been previously removed from the board, this time with the spar resting in the marked location on the block. Glue the halves together at the center joint with epoxy. Have "wet" joints, using plenty of glue. We like to punch angled holes in the joining surfaces with a pointed wire and then work the glue into them. When set, these "nails" make for a stronger joint. During the joining of the halves, be sure and glue the two W-1 ribs to each other as well as to the spars and leading and trailing edges.

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24. Take the wing off the board and remove the jig tabs Cut from the front toward the die cut slit at the back. Sand the trailing edge and the ribs even.

25.

Repeat step 20 on the bottom of the leading edge.

26.

As the ribs get smaller toward the tip, the spar pro- the ribs. trudes down below the rib at the back of the spar hole. Sand the spar to the rib contour.




27.

Add 1/4"x1" fill in blocks behind the center section leading edge as shown in the accompanying drawing.


28.

Pin and glue a piece of 3/32"x4" planking (cut from a 36" long sheet) to the top of the spar on half of the wing.

29.

Immediately turn the wing over and glue the bottom sheet in place. The reason this is done is to keep any bowing action of the wet glue balanced out, helping keep the wing true.

30.

Apply Sig-Bond to the ribs and leading edge. Use a glue gun or a slim, pointed balsa stick to reach back along the ribs.




31.

Pin the sheet down to the ribs and leading edge. Use plenty of pins to insure that the planking is held securely against the structure. Don't wet the planking unless it is necessary to get it to bow to the shape of the wing. If it will bend to shape, do it dry. As soon as one sheet is pinned down, repeat the process on the opposite sheet.



32.

Repeat step 30 on the other wing half. Have a good fit and use plenty of glue in the center seam. This is a main factor in wing strength.

33.

Add the bottom trailing edge planking. We recommend that this be glued on with epoxy as was the top piece of trailing edge planking. This locks the wash-out twist into the T. E. with the extra strength of the epoxy and will make it immune to being disturbed by covering shrinkage.

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34. Using the waste ends of the planking sheets, cover the top of the wing center section. Be sure and use plenty of glue in the center seam. Split the waste piece from each main 36" long planking sheet between the center section and the tip planking of each wing panel. There is enough wood in the waste ends that a little extra can be left to make a neater, rounded corner when trimming.
This is not shown on the plans but if you will look at the pictures farther along you will see the kind of rounding referred to.

35.

Plank the top and bottom of the tip sections.



36.

Add the 3/32"x3/16" cap strips.

37.

Glue on the 3/16" x 3/4" leading edge caps.

38.

Trim and sand the leading edge to contour.

39.

Partially shape the wing tip blocks (using the outline on the plan as the top view pattern) and glue and tape them in place. Carve and sand them to the shape indicated in the accompanying cross section drawing. If you wish to hollow them for lightness, only tack glue them on and after shaping, remove the tips and gouge out the interior before regluing on permanently.





40.

Check the servo and/or servo mount you intend to use in the wing for aileron control and saw out an opening in the bottom of ribs W-1 to accommodate it. The opening being sawed in the photo is 2-5/8" from the back of the spars, so as to leave 2-3/8" between the faces of PW and PS, the amount of room required for an AM-4 vertical plastic servo mount for a Logictrol SM type servo. Remove the sawn out section of Ribs W-l.

41.

Epoxy glue the plywood dihedral brace PW in place on the backs of the spars.

42.

Add the rear piece PS to form the back of the servo compartment. If your servo requires a wider hole, PS may have to be cut down slightly in height.

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43.

Glue scrap pieces of 3/16"x3/4" wood on each side of the opening against Ribs W-2.

44.

Plank the bottom of the center section, except for the servo compartment opening, with 3/32" sheet wood waste from the main planking sheets. Use plenty of glue in the center seam.

45.

Glue hardwood pieces to PW and PS to serve as rails to hold your aileron servo mount or servo.




46.

Mark the outlines of the areas in which the 1/16" plywood center section pieces WT will be inset and cut out a 1/16" deep cavity.

47.

Smooth the cavity with a small sanding block.



48.

Epoxy glue the 1/16" plywood WT pieces into the cavity. Line them up straight with the angle of the center section just ahead of them by laying a ruler along it as shown. Leave the rear edge uncut until the aileron is installed and the wing is being fitted to the fuselage so it can be trimmed to the exact dimensions required.

49.

The aileron horns are bent in a steel jig by hydraulic power. However, due to variations in spring tension in the wire, there may be slight variations in the horn angle. Set the pair of horns side by side, as shown in the photo. If one is bent farther then the other, give it a twist back, using two pair of pliers. Careful! It is easy to overbend.

50.

Notch the formed aileron stock to receive the aileron horns and drill a hole for the end. Epoxy the horns in.




51.

Glue the hinges into the ailerons first. Fit the ailerons to the wing and cut slots for the hinges into the wing. Finally, glue the aileron into the wing hinge slots.
IMPORTANT: It is best to cover the wing and ailerons separately before joining them together, particularly when plastic film covering is used. This will leave steps 51, 52, 53 and a small area of covering to be done after the main covering job, but it is the easiest in the long run. The prototype model in the pictures was done by covering the ailerons with silk before fastening them to the uncovered wing. The wing was covered after completing and mounting. Unlike plastic covering, which requires access to the wing edge with an iron, the silk can be lapped down in the gap between the aileron and wing, and glued on with dope.

52.

Glue the aileron hinges into the wing first and allow to set up. Epoxy the tubing on the aileron horns onto the trailing edge of the wing and the bottom of WT. The tubing may not actually touch the back of the wing and/or WT, but do not force it into place. Let the tubing adopt whatever position it takes from the lineup of the ailerons and surround it with epoxy glue, allowing the glue to fill any gaps.

53.

Fill-in the section around the tubing and WT with pieces of 1/4" x I" trailing edge stock. Notch out to fit over the tubing and clear the horns. Use epoxy and be careful not to use too much or it may squeeze into the tubing. Sand down the T.E. stock as required, to fit on the fuselage.


About The Wing Fastening Options
The kit builder has his choice of two ways of mounting the wing on the fuselage.
  • Method One, using nylon wing bolts, is probably the most popular, but also requires more work and tools. Because of the more complex construction, Method One is fully illustrated in the photo building sequence.
  • Method Two, using rubber band fastening, was used on the prototype Kavalier. It is considered "old-fashioned" by some, but it has advantages of value to many builders. If you are a novice flyer, not able to make smooth landings every time, or if you fly from a rough field, where "cart-wheel" landings can happen, Method Two will help prevent damage to the model. With the rubber band, the wing can shift, yield or come off entirely when subjected to an overload. During construction, Method Two is simpler for beginning builders to accomplish.
All information necessary for installation of Method Two is shown on the full size plan. About the only departure from the picture sequence, other than leaving off several parts, is to cut out the dowel holes in the printed fuselage sides before covering them up with the plywood doublers. Later on, after the fuselage is assembled, all that need be done is to drill the holes on through the plywood doublers, slide in the dowels across the fuselage and glue scrap wood above them to brace them to the top of the fuselage. Use No. 64 rubber bands to strap the wing in place. Use 10 or 12 bands, 5 or 6 on each side when doing aerobatics. You may use eight for test flights, if the last two are crossed from left to right side and right to left over the wing to make sure the rest cannot slip off in flight.

Please keep in mind that rubber bands vary in stretchiness and strength. Stretch each one to its limit and inspect for flaws before using. If the wing does not seem to be firmly attached, add more rubber bands. Wash rubber bands between flying sessions to remove oil. Oily bands may slip off the dowels.

IMPORTANT NOTE:
The threaded aileron horns now being furnished are about 1/4" longer between the arms than the horn shown on the plan (unless it has been corrected.) Position the new horns as they will be when installed in the wing and drill the hole in the aileron father out than shown in the drawing, as required for proper placing.