|KAVALIER RC39 FINISHING|
|The Sig Pushrod Connector included in this kit can be used for attaching the nosewheel pushrod cable to the steering are as shown here.
Additional pushrod connectors can be purchased (SIGSH736) for use on the throttle and nosewheel servo arms. Adjust by loosening the set screw and sliding the cable.
Tips On Tanks
Assemble the tank hardware as shown in the photo.
|We occasionally receive suggestions from builders that a removable hatch be designed into a model for access to the gas tank. Our opinion is this is not the best method in most cases. The hatch opening makes the nose weaker and there is no good way to keep oil from leaking in around the hatch. A method of fastening has to be built into the fuselage to hold a hatch in place.|
Modern plastic tanks are virtually indestructable under normal use and bursting or cracking is almost unknown. If you use Sig Heat Proof Silicone tubing (which will not harden or deteriorate in fuel) in the plastic tank, the tank will seldom have to be removed. We have models in which the tank has been installed for three or four years without ever needing removal. So it is quite practical to put the tank in semi-permanently. Check the models at a contest, you'll find that the majority have sealed noses, as does this kit.
Read this before you drill the 7/8" firewall hole.
Some fliers prefer not to bring the tank cap through the firewall as is shown in the construction sequence in these instructions. Instead they drill two holes for the vent tubes only and make the vent tubes long enough to extend through the firewall. This method requires little sealing but it is more difficult to install and remove the tank. The best way to manage this is to feed long pieces of fuel line through the holes and attach them to the tank in the cabin area. Steer the tank into the nose as the tubes are pulled back through the holes. If you are undecided as to which method you should use, my advice is that the large hole installation shown in the construction pictures is the best for beginners.
Put scrap wood supports under and at the back of the tank. The front is supported by the 7/8" hole in the firewall. Seal the tank cap in the hole with G.E. Silicone Bathtub Seal or Devcon Seal-It. Put an oil-proof finish on the firewall and in hole before sealing the tank cap. Get some of the sealer on the sides of the hole and also put a bead over the edge of the cap on the front. Should you need to remove the tank, break out the scrap wood supports in the rear and push out the silicone rubber seal around the front cap. Reach into the fuselage and guide the tank outside.
Some builders, after putting their receiver battery in a plastic sack, taping it shut, wrapping it in a foam rubber package and stuffing it into the nose under the tank, then stuff paper toweling or foam rubber in to fill the nose compartment and keep everything firmly in place.
|After installation, put fuel tubing on the vent tube and run it to the outside of the cowling on the bottom, so that fuel overflow is not blown over the wing-fuselage joint, where it may leak into the fuselage. The best way to fill the tank is to take off the fuel line to the needle valve and pump the fuel in there until it runs out the vent. Be sure and use a filter on your fuel supply can, and it is a good idea to have a filter between the tank and needle valve also.|
If the engine you are using is equipped with a muffler pressure tap, make use of it for more even fuel feed and reliable operation. The hookup for pressure is shown in the picture. To fill the tank, remove fuel line from the needle valve on the engine and pump the fuel in. When the tank is full, it will overflow through the muffler pressure line. Use transparent or translucent fuel line so you can see the fuel starting to overflow when the tank is full. Should some fuel happen to get in the muffler, drain it out before starting the engine. Do not try to fill the tank in reverse from the pressure line, the tank will not fill properly and fuel may be forced into the engine.
Radio Equipment Installation
The most convenient method of installing servos is on the plastic mounts which most radio equipment makers offer with their outfits or as an accessory. These are screwed to hardwood mounting rails for fuselage servos or to hardwood blocks for mounting in the wings. Instructions for the use of these mounts are included with them.
Servos for which plastic mounts are not available can be screwed directly to the two 3/8" square hardwood rails placed across the cabin, three abreast as shown in the accompanying drawing. With rubber grommets installed in the servo mounting holes, mark the spots for drilling the pilot holes for screws. Space the servos at least 1/8" apart and do not have them contacting the hardwood mounting rails except on the grommets. Using a washer on the wood screws, mount the servos to the rails. Do not tighten the screws down against the grommets since this will cause vibration to be transferred to the servos. The washer should rest against the grommet without compressing it.
Cut a slot in the fuselage top planking 1/4"x1-1/2" on the left side of the fin. Bring the rudder push rod through this slot by bending the RC link as required to clear the fuselage. A variety of quickly detachable push rod retainers are available from the Sig Catalog for hooking the push rods to the servos.
The switch may be mounted wherever convenient on the side of the model, preferably the side away from the engine oil.
The receiver battery pack should be wrapped in foam rubber sheet, held on with rubber bands. Place it as far forward as possible, under the tank. It is a good idea to put the package in a small plastic bag, taped shut around the battery cable to protect the battery from accidental fuel leakage.
The receiver should be similarly wrapped up in foam rubber to protect it from engine vibration. Cover it with a plastic bag also. Stow this package in front of the servos. Make certain that the receiver will stay in place during aerobatic maneuvers.
|NOTE: Some R/C sets have one reverse direction servo that will require an opposite hookup than that shown in the above for Logictrol radios. Mosr fliers use the reverse servo on the rudder. This puts the nose wheel pushrod against the fuselage side without a cross-over being required.|
Cable Pushrod Installations
Here are some typical uses of tubing-cable pushrods. Use scrap block standoffs where required to hold the cable in position. The model shown is not the Kavalier.
The control homs should be installed before covering, then removed until covering is completed. The original Kavalier, had a silk and dope finish. This type of covering makes a fairly hard "shell" on the balsa so plywood reinforcement in the control hom area was not necessary. In fact, we have never reinforced surfaces around homs and they have always stayed intact. If you cover the model with something else, or even if the dope finish is light, it will probably be better to inset a plywood scab into the wood (use epoxy) as shown in the photo. This will keep the hom from pulling out of the wood.
Note also, in picture 135, the slot for the rudder pushrod.
The elevator pushrod exits through the opening in the fuselage rear. Open it up as required to pass the pushrod. The pushrod wire may be bent slightly if it tends to rub on the fuselage. Take note that the elevator hom arm is centered on the elevator, not the hom mounting holes, which must be offset to locate the arm in the center of the fuselage opening.
NOTE: If the R/C Link fits too tightly in the nylon horn holes, drill the holes out with a no. 51 size drill.
Having the proper connector makes servo installation much easier. We show here a variety of ways to attach push rods to servos.
You should decide on which type of fittings you will use in the case of the cable pushrods and have them on hand during fitting construction because the type chosen will affect the location of the pushrod exit holes through the firewall, etc. The balsa pushrods to the rudder and elevator are not limited as to location and can be adapted to any of the types of connectors shown without preliminary planning of exact position.
COVERING AND FINISHING
Don't skip covering the fuselage and tail just because they are solid wood. Painting them without covering first is not enough. They will be much more resistant to splitting and breaking on hard impacts if they are covered with something - Sig Silk, Silkspan, Sig Silray, Sig Koverall or iron-on covering material.
The manufacturer's directions for applying iron-on coverings are packed with the material. Follow these closely, for different types of covering have different iron-on temperatures and techniques of application.
Whatever kind of covering you desire to use, it will not conceal a rough framework. Sand carefully with fine sandpaper before beginning to cover.
Covering With Silk, Silkspan, or Silray
NOTE: The following photos show another model, but the covering method is the same. Sig Koverall is applied dry but is doped on in the same manner as shown . Shrink with heat. See directions on the Koverall package.
Although we refer to silk in the directions, all of these coverings are applied wet in the same manner as follows:
Brush an unthinned or very lightly thinned coat of clear Sig Supercoat or Sig Lite-Coat Dope over all parts of the framework that will contact the covering. When dry, resand with fine sandpaper, to remove any fuzz or raised grain. Brush on a second coat and sand again.
|The bottom of the wing is a good place to start covering. Cut a piece of material about 1/2" larger all around than half of the wing, with the
grain running lengthwise. (The grain of woven materials runs parallel to the finished bias edge.) Some builders next dip the piece in water and apply it to the wing. I find that the silk sticks together and
takes a lot of pulling and smoothing to get it in place so we do it a bit differently as shown in the photo.|
Pin the dry covering in place and "paint" the water on with a brush.
Go around the edges, pulling out wrinkles and stretching the material smooth. You need not pull it up drum tight, in fact going to this extreme is not advisable. Just pull out all of the wrinkles. Use pins, if necessary, to hold the silk smooth, though wet silk usually stays in place without too much pinning. We like to fasten one end - in this case the center joint of the wing - pretty firmly with pins so that you can pull against this anchored end in stretching the silk the long way.
Brush around the outside edge of the stretched silk with clear dope. The dope will soak through the material and adhere to the dope already dried into the framework. Allow to dry.
Trim off the edges with a sharp blade. We find that a thin double-edged razor blade is ideal for this, but a single-edged blade does okay and you can't cut your fingers on it. On the bottom, trim off flush with the wing all the way around. Go over any rough areas or places that have not stuck down properly with more dope and press the loose spots down as the dope is drying and getting stickier.
The top half is done in identical fashion except that the silk should be brought down over the edges instead of being trimmed off flush. On the front, lap the silk over the edge of the bottom, over-lapping about 1/8". At the back, bring the material down over the back edge of the trailing edge but do not lap it over the bottom covering.
Use the same process on the tail section and fuselage.
Allow the water to dry out of the wood before applying the first full coat of clear dope. On the open framework area on the wing, brush the dope on sparingly. If too much is applied, the dope will be rubbed through the material and will run down the surface on the inside and form a puddle. When these puddles dry, the large amounts of dope solids in them cause more shrinkage than the rest of the covering and a scarred area results. So apply dope very lightly the first time over. A second coat will seal most of the pores of the material and from this point, running through will not be a problem.
Use one or two coats of regular Supercoat clear on the wing to shrink the covering. After that, unless the covering is still not tight and unwrinkled, Sig Lite-Coat low shrink clear dope is recommended to help prevent warping. The solid wood fuselage and tail can have Sig Lite-Coat from the beginning if desired. Sig Supercoat Color Dope has low shrink qualities.
A third coat of clear should provide a good base for color. Sand lightly when dry with 220 grit 3-M Tri-M-Ite no-load paper. Don't bear down on the edges of the ribs or the silk fibers will be cut through. The color dope may be brushed or sprayed.
|Supercoat Color Dope should be thinned with 10% or more Supercoat Thinner for brushing. This helps prevent brush marks and gives smoother coats. Flow on wet coats and avoid rebrushing back over an area already painted. For spraying, thin dope about 50 - 50. Add more thinner if the dope does not go on evenly.|
If high humidity causes the dope to "blush" or turn white, the test way to handle this problem is to wait until the humidity situation improves and apply another coat of dope. This will eliminate the blush. If it is necessary to dope during high humidity, Sig Retarder may be used in place of part of the Supercoat Thinner (amount depends on the humidity) to reduce the tendency to blush.
Painting the entire model white is recommended for a good color base, particularly when white is part of the color scheme. Color coats can be sanded with 360 Tri-M-Ite or 400 or finer wet paper. When using masking tape for trimming, seal the edge with a coat of clear dope to prevent the color dope from bleeding under the edge. Don't leave the masking tape on any longer than necessary. The longer it is on, the harder it sticks.
Complete the job with several sprayed coats of clear over the color scheme. This seals the colors and adds gloss. For a smooth, realistic finish the final coat may be rubbed down with Sig Rubbing Compound. For best results, it is not a good idea to try to mix different brands of paint. Use SIG products from the start.
Finishing The Plastic Cowl
The plastic parts should be sanded to remove the gloss before they are painted. Don't use coarse sandpaper, which can cut deep scratches. These scratches may open up during doping (which softens the plastic) and become more noticeable. Instead use something like 220 3-M Tri-M-Ite no load silicon paper to start and polish down with 360 Tri-M-Ite or 400 wet paper before color doping.
The plastic cowling and wheel covers may be painted with Sig Supercoat Dope. Care should be used not to apply heavy, wet coats of dope. Put on light coats and allow them to dry thoroughly before applying a second coat. A spray gun is a good method of getting a good finish with a minimum amount of dope. Be especially careful with spray cans not to wet the plastic too much. Spray several light dusting coats with adequate drying time allowed. Plastic may also be painted with Sig Plastinamel, Sig Skybrite, K&B Super Poxy, Hobbypoxy or DuPont Dulux Enamel. Don't use other paints without testing them first on scrap plastic.
Painting The Canopy
We recommend Sig Plastinamel for painting the framing outlines on the canopy. Dope is very difficult to use on canopy plastic because of its warping action. Epoxy paint can be used, but it does not stick on the plastic quite as well as Plastinamel. Sanding the gloss off the plastic will help adhesion. Other enamels and plastic paints can be used, but test in advance on scrap, because no assurance can be given for other types.
Various brands of servos can give different control movement direction and amounts of travel. For this reason, follow the measurements below when setting the Kavalier up for flight rather than any particular hom hole drawn on the full-size plan or visible in a Kavalier picture. Shift the R/C link to whatever hom hole will produce the amount of movement shown in the drawings below. Measurements are made at the trailing edge of the control surface.
The control measurements below are suggested as a beginning. Test flights may indicate a need for more or less movement, depending on individual model differences, C. G. location, your personal preferences, etc.
For training purposes, do not carry excessive elevator movement. Use only enough to properly perform a nice sized loop. Over control with excessive movement can get a novice in trouble. After you are more expert, additional movement can be used, if desired, for quick snaps and other violent maneuvers.
The recommended Center of Gravity locations are shown on the side view on the full size plan. Extend these marks to the bottom of the wing at the tips. (A handy way is to stick a piece of masking tape on each wing and mark the positions on it.) For the first test flight, balance the Kavalier by suspending it on the finger tips placed on the bottom of the wing on the first mark. Balance with an empty fuel tank, but with all other equipment installed and the model completely finished and painted. Add lead to the nose, if necessary, to get the model to hang level. Be sure and fasten the weight securely. Do not attempt flight tail heavy.
The "Test Flying" position is on the nose heavy side. When slightly nose heavy, the model is more stable and less likely to stall or snap froll from over-elevating. It also cuts down reaction of the model to control movements and this is good during test and practice flights, to help prevent overcontrolling. After the model has been test flown and initial trimming accomplished you will want a little quicker response. Move the balance back to the "Sport Flying" position.
Some aerobatic capability is sacrificed with the two forward C. G. positions, so for making deliberate snap rolls and spins a position farther back may be required. Move the C. G. back slowly and check results and control response in the air at a good altitude. Don't move the C. G. back any farther than necessary. The "Aerobatics" balance point should be considered the rear limit and moving it back any farther is not recommended unless you are an expert flier, with a purpose for doing so.
The Kavalier is not a basic trainer. If you have no previous RC flying experience you cannot successfully fly a responsive design like the Kavalier, particularly on the test flights. A basic trainer, such as the Sig Kadet, should be used for a number of hours before attempting to fly the Kavalier by yourself.
It is recommended that novice pilots should not attempt to fly the Kavalier without the assistance of an experienced pilot. Contact the local model club or ask your hobby dealer for the names of good fliers and a suitable location for flying.
Many hours of work are involved in the construction of a model and it can all be lost in a moment of beginner's indecision. A skilled flier can help you get past the first critical test and trimming flights without damage to the model and give instruction in proper control.
|Be certain to carefully range check your radio equipment and see how it operates with the engine running before attempting test flights. A lot
of problems can be avoided if the engine has been well broken-in and the idle adjustment perfected on a test block or in another airplane before installation in the model.|
Takeoffs with the Kavalier from grass fields are easily made if the grass is not too long or the ground too rough. Generally a lot of elevator application is required for liftoff. Be prepared to relax control pressure partially after becoming airborne so the climbout will not be too steep. On surfaced or smooth dirt runways less application of elevator will be needed.
If a good, smooth take-off surface is not available, the model can be hand launched by the pilot's assistant. (Do not attempt to hand launch by yourself, instant action on the transmitter may be required.) Holding the front part of the fuselage with the left hand and under the tail with the right, run into the wind at a fast trot and thrust the model forward with the nose slightly up in a spear throwing motion. It is not necessary to achieve a lot of velocity in the launch-it is more important that it be released smoothly and with the wings level. The model may dip slightly and then should begin climbing at a slight angle. If it does not begin to climb after about fifty feet of flight, apply a small amount of up elevator to lift the nose.
Use the ailerons to keep the wings level and headed straight into the wind until about seventy-five feet of altitude is obtained. Keep first turns gentle and not steeply banked. Stay up wind of the transmitter. Use trim levers on your radio equipment where necessary to obtain straight and level flight with the control sticks in neutral position but don't attempt to make these adjustments until the model is at a good altitude. Throttle back at altitude to find out the model characteristics in a gliding condition so that some indication is seen of what to expect during the landing approach. It is a good idea to make several practice landing approaches at a good altitude to get the feel of the model for this approaching critical maneuver. Make your final and complete landing approach while your engine still has plenty of fuel remaining so that the engine is not liable to stop before completion of the flight. This will allow application of power if the approach is undershot. Notice the percentage of missed landings at an R/C flying field. Those undershot greatly outnumber those missed by overshooting. So, if an approach that looks a little high is maintained, chances are good that a spotlanding can be made.
After each test flight, readjust the R/C clevis links on the pushrods so that the trim levers on the transmitter can be returned to a neutral position. It will take several flights before exact trim is established on all axis of flight.
|© Copyright SIG Mfg. Co., Inc.|
SIG MFG. CO., INC............Montezuma, Iowa 50171-0520
|LIMIT OF LIABILITY:|
In use of our products, Sig Mfg Co.'s only obligation shall be to replace such quantity of the product proven to be defective. User shall determine the suitability of the product for his or her intended use and shall assume all risk and liability in connection therewith.