FW TA 152 Instructions

JK Aerotech -- 10800 SE Orient Dr, Boring OR, 97009  -- Web:  www.jkaerotech.com -- Phone: 1-503-663-4081

We carry all the radio gear, engines, and all the accessories for our kits - call or check the web.

The Focke-Wulf TA 152, had the war lasted a bit longer, could have been a real factor in holding off the allies. One story states that a pair of Mustangs intercepted Kurt Tank, Focke Wulf designer, as he was test flying one of the first 152s. Tank simply pulled out the stops and left them in the dust. The TA 152 was a stretched version of the FW190 with a longer wing to take advantage of high altitude flying. Just like the real TA 152, our foamie TA is quick and incredibly maneuverable. The long span give you combat types a little more advantage trolling for streamers but rolls are still fast and handling very predictable. If you run out of gas before the match ends just sniff out a thermal and you should have no trouble finishing the round.

Foamies make a very interesting type of project. They are quick to build and extremely durable. The basic premise behind this type of construction is to build an airframe that will stand up to the rigors of combat flying yet handle good enough to allow the weekend fighter jock a plane that he won’t be afraid to try crazy stuff with. We have run these planes into the ground, buildings, trees, blackberries, fences, and other planes and still had a plane that, when dusted off and checked over, would still fly. It is a sad sight indeed when a balsa plane tangles with one of these foamies. The first thing to keep in mind is that these are functional planes, not beauty contest winners. They are designed for unfettered fun. Part of that functionality is the way they are built. Servos can be simply pocketed in anywhere on the fuselage where it is most convenient or hid inside the canopy for a cleaner look. The pushrods can be left hanging out or buried in the foam. Sometimes the simplest most direct methods are the easiest and best. We will outline how we build this plane. You are free to experiment and try other innovative ideas. If you come up with a good technique, let us know about it and we will post it on the web. Now go out and have a blast! 

Read this before you start building!   If you intend to combat with this plane, be safe and ALWAYS wear a helmet or hardhat and safety glasses!!

The construction is very much the same as all of our foamie kits; however, we will take you from start to finish as if this is your first plane. First, it would be helpful to have a few basic tools handy.

·         Nylon reinforced filament tape 

·         Packing tape, either clear or colored. Most kits come with 1 roll included

·         Possibly 5 min. epoxy

·         Possibly fiberglass cloth and epoxy resin

·         Razor blades and/or large snap blade knife

·         Silicone sealer or builders construction adhesive

·         Goop type glue (use only on taped up Styrofoam as it will melt plain styro)

·         Sanding board and loose sheets of sandpaper--50 grit for rough sanding and 100-150 grit for finish sanding

·         Various tools for gouging out the cavities for the radio gear. Try sharpening an old flat blade screwdriver to a chisel tip. Woodcarving tools, pocketknives or potato peelers work great too!

·         Flat table that you can cut against

·         Can of 3M-78 spray glue or something similar that will not melt the foam. (If 78 is not available, you can assemble the "war bird" by priming the foam with water based contact cement. We have used all brands and can supply small bottles of the one we found to work the best. See the “CONTACT CEMENT NOTE” below.)   We have found that Formica brand or Wilson Art brand of glue works the best.

Important Note:

Contact Cement note: in every instance where 3M-78 spray glue is referenced, you can substitute water based brush-on contact cement that will not eat the foam. It is always recommended to prime all of the foam - wing and fuselage - with an adhesive prior to taping. Water Based adhesive, much like the 3M-78 spray glue, will not eat the foam but will an hour or so to dry enough to stick. In most cases, we prefer it to the spray because of the lack of over-spray and fumes. We have performed tape holding tests and found that the water based adhesives actually held the tape tighter than the spray glue. Get several of the cheap, throwaway brushes to apply the adhesive and brush on a thin coat. For the best performance, let dry then brush a second light coat on. After the adhesive is applied, it is best to allow it to dry thoroughly. This usually takes about an hour, but you can leave it to dry overnight or longer if you want. You can also use it to stick doublers on. A Monokote Iron used on a doubler will re-activate the glue and mold the coroplast to the foam. Experiment on a scrap piece of coroplast before applying heat to be sure you don't melt it. The iron will also shrink out some tape wrinkles and bond the tape to the foam tightly. This glue works especially well to glue the tail group into the back of the fuselage. The process is outlined later in the instructions.

Kit Contents:

·                     2 piece fuselage--right and left

·                     2 tapered wing panels

·                     1 center section

• 2 - 1"x24" 4mill coroplast strips for ailerons

·                     2-mil coroplast sheet with fuselage doublers

·                     4-mil coroplast horizontal stabilizer and vertical fin 

·                     4 spruce spars

·                     2 fuselage spars

·                     1 roll colored packing tape

·                     Firewall wood

·                     Control horns and pushrod wire

·                     Instruction manual with patterns

Tail

1. First cut the tail sections out of the corrugated plastic sheets. This material is very stringy and will not die cut cleanly so carefully trim away with a razor blade or scissors. Save the extra coroplast as you will need it later. Look at Fig. 1 for a side view of the hinge line in the elevator. (Note: These instructions will refer to drawings that are included at the end of this manual.) Find the approximate hinge line by slipping the elevator into the fin (or just hold it up to the fin and line the tab and slot up) and pick a rib that will allow the elevator to move up and down without binding on the clearance hole in the fin (on this plane about 1 inch). After finding the rib where you want the hinge, slice only the bottom surface of the coroplast. Then trim the flashing off so the hinge will bend up and down without binding on itself. Make dashed cuts in the hinge because this makes the hinge bend easier. We take a Xacto knife and make ½ inch cuts every ¼ inch or so. Bend the hinge up and down a few times to loosen it up.

2. The tailpieces are glued together with Goop (that’s the retail name - E6000 is the industrial name). A small bead along each side of the fin will do. Then block them so they will dry straight and perpendicular. Thick CA or 5-min. epoxy glue will work also but will not be as crash resistant. Silicone glue will work too, but don't get it anywhere you will need to tape or glue. Set the tail aside to cure and start the fuselage.

I actually started shaping the canopy before I cut it off on this build. I used a band saw - it would be easier to cut prior to shaping the fuse. Put the protective jacket that comes off the fuse side under the fuse if you use a band saw - this will keep the fuselage level and square with the band saw blade.

Fuselage

3. We supply a piece of plywood and a pattern for the firewall. The fuselage is about the right length for most .25 size glow engines. Cut the pattern out and spray glue it to the plywood supplied and saw it to shape. Use the centerlines to layout the motor mount position. If your engine/mount combination is longer than most, you may need to trim the front of the fuselage so that the firewall, mount, and engine combined will position the prop and spinner to clear the front of the fuselage doubler. This is much easier to do before the fuse is sanded and contoured. If you cut the nose, be sure not to change the firewall angle.

4. No trimming should be needed on the nose for most engines of the .20 to .25 size, but set up your engine/motor mount and check for nose length just to see that the prop will clear the front of the fuse doublers. We trim the fuse doublers if the prop interferes with the front of them.

5. After setting up the engine and firewall, you will need to glue the two halves of the fuselage together. Use 3M-78 or other foam compatible spray glue or use epoxy if you want. If you use spray glue, use some caution and do not put too heavy of a coat of glue on the foam. Be sure to let it dry to a strong tack before sticking the two halves together. If the coat of glue is too heavy or the fuse halves brought together before drying, it could melt the foam! If you use glue other than 3M-78, work quickly and blow the glue or fan the parts to dry the glue before the foam starts to melt. Use a piece of cardboard or scrap coroplast to smear any globs of glue out before they can melt the foam. You can also use the water base contact – use two coats and let dry thoroughly. You can cut the canopy off now or later but now will be easier if you have a band saw. Lay a fuse doubler on the side of the fuse and mark the canopy line and cut it off using a long sharp knife or band saw. You can also cut the under belly plate off the fuse and set both aside until later. If you cut it off later, follow step 11.

6. We recommend using 4-40 T-nuts (blind nuts) to fasten the motor mount to the firewall. After getting the T-nuts set up, stick the firewall to the front of the fuse with a coat of spray glue or 5-min. epoxy and sand the fuse to the shape of the firewall. Use coarse sand paper (40 grit or so) to roughen the shape and then smooth it with 100 to 150 grit. Go ahead and shape the rest of the fuselage too. We have some fuse cross-section drawings to give you an idea on how to shape the fuselage but basically the TA 152 is somewhat rounded at the cowl, then turns to a oblong shape from the back of the canopy to the tail. The nose is sanded with a sanding block to match the firewall. There is plenty of room in the TA fuse for the tank. As you sand the fuse, you will want to rough shape the canopy. The TA canopy is very tiny and skinny with a slant in each side of the canopy.

Fuel Tank

7. The fuel tank is cut in at this time. We like to go in from the left side of the fuselage, at about the center line, and dig a pocket that fits the tank snugly with about 3/8 inch of foam left behind the firewall for strength and cushion in case of a crash. We like to crowd the tank close to the left surface of the fuse to give us a little extra foam on the right side to make a tunnel for the throttle servo rod without accidentally boring a hole into the tank.

8. You will have to accommodate the lines coming from your particular tank. A good way to help everything slip into place is to make the pocket long enough so that there is a little space for the fuel and vent tubes at the front of the tank area. After slipping the tank in, cut a chunk of scrap foam to wedge the tank in and keep it from sliding forward and possibly pinching the lines in a less than elegant landing. Locate and drill holes for the fuel and vent lines and install the tank.

9. The TA fuselage is a small diameter so a 4 oz. tank is about the maximum. Crowd the tank as close to the left side of the fuselage as you can to leave enough room for the throttle servo cable to go beside the tank on the right.

Servos

10. There are several ways to get the aileron servo in position. The simplest is to use one servo in the center and run pushrod wires to the aileron horns. A standard servo works fine. If the bottom of the servo hangs through the wing, you can protect it with the under belly slab that was cut off earlier --more on that later when we are covering the wing.

11. You are going to install the throttle linkage now. Before you do, you will need to remove the canopy (if you haven’t done it already) from the fuse. We used to install the throttle linkage after the plane was taped, but our good friend “Mr. Clean” showed us a much better and easier way to route the linkage. The first thing to do is locate and cut off the canopy from the fuselage. Temporarily tape the fuselage doublers on to define the canopy line. Mark and cut it off using a long, sharp razor blade (we use long snap blades). After slicing it off, set it aside as it will probably need to be hollowed out a little to clear the servos before covering it with tape.

12. Now the throttle servo is to be positioned. Remember, the tank is crowded to the left side of the fuse because most throttle arms are on the right side of the carb so this is the side we are going to drill a hole through the firewall for the linkage. Temporarily install the engine so we can lay out the throttle linkage path. With the engine on the mount and the muffler off, it is very easy to locate where the hole for the throttle linkage should be drilled. Drill about a ¼ inch hole so the linkage will exit straight out from the firewall and intersect the throttle arm. We like to use flex cable from the throttle to the servo in the canopy area, but you can also use a straight length of thin piano wire if you sink the servo down in the foam far enough so the wire is close to a straight run to the throttle arm. However you do it, simply cut or sand a groove in the foam, or drill a hole from the hole in the firewall you intend the linkage tube to go through up to the front right side of the canopy. Imbed the tube into the foam and secure it with 78-spray glue or tape. Locate the throttle servo on the right front side so that it will work the cable or pushrod smoothly and cut it into the floor of the canopy. We use a micro servo such as a Hitech HS81 or HS60. Depending on your installation, you may want to sand the floor of the canopy area down to lower the servo and clean up the canopy area a bit. Be sure to leave a little foam at the side to stick the fuse doubler to. We try to crowd the throttle servo as far right and to the front of the canopy as we can. If any of this seems confusing, you can go to our web site where we have all the details pictured under the TA 152 instruction set. Hooking up the throttle is much easier to do before the doublers are on.

Firewall

13. After the tank is fitted and installed, cover the entire firewall with strips of strapping tape working from the bottom to the top. Let the ends cover the nose back about an inch or two. This will strengthen the nose and start sealing the firewall. We have also recommend covering and sealing the firewall with the colored packing tape at this time.

To get a groove started in foam, use a sharp razor blade and slice along each side of the spar, then use a the end of the spar to pick and roll the foam out of the groove. finish up with a light sanding to smooth the groove out.

Cut a 5” piece off each stick and set aside – they will be used for the wing center. 

Strike a line level with the horizontal tail about a ¼” down from it and sand a groove that just fits the spar. Use epoxy, wood glue, or Polyurethane wood glue (recommended) to glue them in and put a piece of strapping tape over them. Sight down the fuse and check that it is straight before the glue sets. The fuse can be tweaked one way or the other if it is off a bit.

NOTE: If you use water base glue on the doublers, brush on two coats of glue and let it dry. You may have to use a Monokote iron to heat the coroplast so the glue will activate and stick. Use a low setting and experiment on a scrap as too much heat will melt the coroplast.

Doublers

15. You should now have a sanded fuselage with a firewall taped on and tank installed so the next step is to prepare the fuselage doublers for gluing on. These are die-cut from 2-mil coroplast material and will cover each side of the fuselage from about the back of the wing forward and will be long enough to make the side of a cowl. If you miscalculate and get the engine a little too far back, it is easy to trim the front of the doubler a little to make it fit or cut it off and use a bottle to make a cowl--more on that later.

16. To prepare the doublers, do two things. The first is to use a blunt object and score the ribs on the inside of each doubler to help them conform to the shape of the fuse. The second is to locate and cut a trap door on the side that you cut the tank in for access to the tank later on (that would be the left side if you cut the tank in on the left). Cut the door on only three sides so that one of the ribs in the coroplast will make a built-in hinge. Cut the hinge just like you did the elevator hinge so the door will open out. 

18. We have included some extra 2-mil coroplast with the kit. It will be the leftover material from the sheet the doublers came in. This will be used for fill between the fuse doublers on the top of the fuselage nose from the firewall back to the canopy and the under belly from the firewall to the front of the wing saddle. It is a great idea to leave the underbelly filler about a half-inch long so you can slip the front of the wing under it when the wing is glued on. You will end up with a nose section that is completely covered with coroplast. Note: to save weight, I only used about4 inches of filler on the top of the TA 152 nose because the front of the plane is so long.

19. This would be a good time to double check the engine fit and location. Check the clearance for the prop/spinner and front of the cowl. Before you can do that, you may have to trim the doubler to clear the muffler. You may also  have to punch a hole for the needle valve to poke through. Since we use pushrod connectors on our throttle arm, we punch a hole for the screwdriver to tighten it.

Here is the key to the outstanding strength of our planes...

20. After fitting the extra 2-mil coroplast top and bottom, glue them on with spray glue. Use a hand tacker or staple gun to staple through the coroplast into the edge of the firewall all the way around. This will make the firewall very solid and able to withstand unbelievable crash forces. If you don't have a staple gun, use 1/2-inch wire nails, upholstery tacks, or even thumbtacks. Just be careful that you don't drive them through the fuel lines that should be already pulled through the firewall.

21. Before proceeding with the taping, prime the fuselage by spraying another light coat of 3M-78 spray glue or brushing a light coat of water base glue over the foam part of the fuselage and let it dry. No need to spray the coroplast as tape sticks extremely well to it.

22. The second major key to the strength of our planes is to wrap strapping tape around the nose from the firewall back to the canopy. Do the same on the under belly from the wing saddle to the firewall. Lay the strips side by side and pull them hard enough to cinch the coroplast down tight to the foam. We use long enough strips to go over the top and down the sides about half way then turn it over and do the belly the same way. Do the same thing with the wing saddle. Lay strips of strapping tape side by side and cover the whole wing saddle and let the ends run up the side of the doublers about an inch. Pull these tight as you put them on too.  When strapping tape is wrapped radially around the nose and wing saddle, you will make the nose of the plane virtually unable to crush or buckle. The strength of this construction will be evident on the first ground plant.

Taping the Fuselage

Now we are ready to start covering the fuselage with the colored packing tape. Curved and rounded surfaces, as found on TA 152s and most other war birds, can be a bit of a challenge to the first-time foamie builder. Our first bit of advice is to relax and don't stress out about a few wrinkles. We really don't care too much about how it looks because these planes are designed to maximize fun, take extreme punishment, and then throw away! Now, that having been said, with a little care, a few tips and experience at sticky-tape handling, you will be able to turn out a reasonable looking product.

TIP: When trying to tape a curved fuselage surface with packing tape, it will tend to bunch and pucker. Stick the tape along the flattest surface and slice the edge that is hanging over about every ½ inch, then starting at the back, working forward, smooth each little flap of tape over the curved edge. The little flaps will overlap each preceding flap, and the curve will be much smoother. After the fuselage is taped up, use a razor blade to open the tail slots and wrap the excess tape flaps into the slots.   

23. The place to start is at the wing saddle. You should already have strapping tape covering the saddle from side to side so now we want to cover it with the colored tape. Start at the trailing edge of the saddle and lay packing tape across the saddle letting the tape run up the side of the doublers an inch or so. Keep laying in strips of tape with about  1 inch overlapping the preceding strip until the saddle is completely covered.  

24. After the saddle is covered side to side, you can cover the fuselage. Start by laying strips of colored packing tape on the fuselage from front to back. We like to start on the bottom and work up the sides. Overlap the preceding strip by about 1/4 inch to 1/2 inch or more until the whole fuselage is covered. Use the tip outlined above to help the tape conform to compound curves, unless you like lots of wrinkles. If you make lots of slits to help the tape conform, it is sometimes good to lay another strip of tape so that the previous slits are covered--even if it means overlapping the strips of tape an inch or more. If your plane will use the doublers to make the cowl, it is a good idea to let the tape run long enough to tape around the front of the doubler to cover the inside of the engine compartment all the way back to the firewall. You should have the fuselage covered pretty well by now. Let the excess edges of tape wrap into the canopy area. You will have to slice it to get it to stick smoothly. Check the canopy fit to see if taping changed anything, and sand it a little if needed.

NOTE: Water-based contact cement is much easier to use than spray glue because you will have much more time to work with the tail group and fuse. Coat the part of the tail that slides into the slot with glue then slide it in and out of the tail slot. Repeat this a couple of times. This will coat the foam on the inside of the slot.  Then slide the group into position. Use C-clamps and something like paint stir sticks for protection. Squish the sides together clamping lightly to hold the sides to the tail and allow to cure in correct alignment. This may take overnight. Then tape up the underside of the tail slot and apply a bead of goop underneath each side of the stabilizer at the fuse intersection. This works very well, is very strong and easy to do. But it takes a little patience to cure.

Install Tail Group

You should now have a completed fuselage ready for wing installation and radio gear!  

Wings

NOTE: We now cut spar slots and supply spruce spars. Since the wings are tapered, the slots will need to be cleaned out a bit towards the tip. Fold up sand paper and drag it through the slot until the spars fit snugly and flush with the wing surface. We highly recommend a polyurethane type wood workers glue to install the spars as it holds incredibly well to foam and wood. Epoxy would the second choice.

Trim the trailing edge of each wing panel so it is a constant thickness and matches the thickness of the aileron stock.

Installing Spars

28. After the wing panels are dry and cured, prepare the spars. We send along four 1/8 x 3/16 inch spruce spars. Since the wing has a dihedral, you will need to join them over the center wing panel joints. The joints should be  “scarf” joints. That’s wood workers jargon for slicing an angle in both ends so they overlap smoothly giving the glue more surface area to join the two pieces of wood. We try to make at least an inch of overlap. We can only send along 24” spars but the wing panels plus the center section will be about 51” total so use the pieces you cut off the fuselage spars for the center section of the wing top and bottom. Cut about a 5 inch stick and scarf both ends off for the joints and check the fit with the main wing spars. Carve and sand the overlaps until they fit nicely in the wing spar pockets.

Again we recommend using polyurethane glue for the spars as it locks them into the foam. If you use epoxy, you will need to use enough to fill the spar slot with the spar in place. Trowel off the excess and let cure. If you use the polyurethane, dampen the spars. Then lay a small bead of glue in the slot. Run the nose of the glue bottle back and forth in the slot to spread it throughout the bottom and sides of the slot. Put a dab on the scarf joint and slide the spars into place. Be aware that polyurethane will expand as it dries several times its wet volume (see note below). So if you use too much, it will leak all over the place. Also be very careful not to get spots of it on the wing surface because the next step is to lay a strip of strapping tape over the spars and tape doesn’t stick to wet glue. Lay a strip of packing tape over the strapping tape and press to seal the edges down completely so the glue won’t leak out. Block the wings at the correct dihedral and let cure overnight.

29. The entire wing surface will now need to be coated with 3M-78 spray glue or contact cement (see note on page 2). Let this dry before continuing. After the glue drys, put one layer of colored packing tape over the center section from leading edge to trailing edge, overlapping each successive strip about one inch. Do this from the center out about four inches. This will insure that you have at least two or three layers of packing tape at the center of the wing out to about 4 inches so the goop will not attack the foam and melt it when attaching the wing.

Look close and you can see the small pieces of tape holding the ailerons at 1/8" gap

Then lay one strip of colored tape over the aileron and wing joint.

this is the aileron after the bottom tape is on

Ailerons

30. After installing the spars, it is time to prepare the ailerons. The ailerons will come already cut from the factory – they will be 1” strips of 4 mil coroplast (see Fig 4). Position the ailerons so the inboard edge will clear the fuse by about 1/4 inch. You could encapsulate these in tape before they are attached to the wing (see Fig. 4) or tape them on the way they are--your choice. Don't worry about the wing tip shape of the ailerons because we will use the wing tip pattern to trim them after they are covered and attached. TIP: When covering the ends of thin parts, trim one side off at the edge and wrap the other over it---just like when using iron-on covering.

31. Center the fuselage on the wing at the trailing edge, and then make a mark ¼ inch from the side of the fuse. This is where the ailerons will start and should give plenty of clearance for aileron movement. First look at Fig. 4 for visual aid on how to hinge the ailerons. Set the wing flat on a table, topside up, and lay the aileron along it. Use three tiny pieces of tape to hold the aileron and wing together with about a 1/8-inch gap between them. Lay a strip of colored packing tape along the top of the trailing edge of the wing and aileron together to create the top “hinge”. Flip the aileron up and lay back on the top surface of the wing and use a small piece of tape to temporarily hold the aileron in that position, which will leave your two hands free for the next step. Stick a strip of tape along the back of the wing and the aileron, smoothing the tape down on the bottom surface of the aileron and the bottom of the trailing edge, then open it up, to lay the aileron flat. Turn the wing upside down and use a blunt object (window screen tool works perfectly) to press the top and bottom tapes together to complete the hinge. Do this to both ailerons and after they are attached, get your wing tip pattern and trim the ailerons to match the pattern. If this is difficult to figure out, see our web instructions for step-by-step pictures. The main idea is for the top and bottom wing tape to form the hinge by sticking them together between the aileron and trailing edge of the wing. This makes a very strong gapless hinge.

NOTE: Make sure the center section has at least 3 layers of packing tape anywhere that goop will be used to glue it to the fuselage. Two layers will be automatic if when taping a wing panel, the tape is started a couple of inches before the wing joint opposite the panel being taped. Then to be extra sure, put a layer of tape from trailing edge to leading edge starting in the middle of the center section and working out about 4 inches in both directions with about a 1-inch overlap.

Taping Wings

32. When covering wings with packing tape, follow this simple taping convention: Lay tape strips from the center to the tip and always start at the back and work forward overlapping about ¼ inch. This way the tape edges will flow with the wind instead of pointing into the wind. Another good idea is to always start with the bottom of the wing so that the finished wing always has the top tape wrapping over the bottom surface. It just looks a little neater.

33. The leading edge should have a couple of layers of tape wrapped around it by the time the top and bottom covering is done. We recommend adding another layer or two of tape to the leading edge for extra protection. Stretching the tape modestly while sticking it down will help it go on smoothly, but be sure to balance the stretching or you could have a wing that bends up or down.

34. Now that the wing is done, it is time to set up the aileron servo. Refer to Fig. 2 for an approximate location. We usually place it at about 1/3 of the chord from the trailing edge of the wing. Hold the servo in position and trace around it. Use a sharp knife to cut a pocket for the servo. Make it a tight fit. The wing is thin at the servo point so the servo will probably hang out the bottom surface of the wing. No problem--after the wing is finished and the servo glued in fit the under belly slab you cut off earlier to the bottom of the wing. It should just about cover the servo. If not, fashion a tiny box from scrap coroplast around it and cover the box with several layers of packing tape. Install the control horns and connect the servo arms with the ailerons using the piano wire provided. We like to use Z bends at the servo end with connectors at the control horn for easy adjustment. There are other ways to connect the servo to the horns so if you have a favorite way, go ahead and use it. 
The TA 152 has a small canopy area, so you will have to use small radio gear in order to fit it all. Use micro HS 81 for the elevator and throttle.

35. The control throws should be about 3/8 inch up or down. This will make the plane handle quick but fairly easy to control at high speed.

36. After the servo is cut in and you are certain of its placement, slide it out for a second. Coat the edges of the foam pocket and under the mounting tabs of the servo with silicone, and slide it back in place. Wipe the excess off being careful not to get it on the fuselage or wing where more tape will go.

37. Hold the wing to the wing saddle in the fuse and eyeball where and how much you will need to cut into the wing saddle for the servo clearance. You will have to cut a hole in the fuse doubler for the pushrods to exit the wing saddle, and be sure there is enough cut out so the servo arms and pushrods will work without binding on anything.

38. It is a good idea to hook the servo to your receiver to check for correct and smooth operation because the wing will be glued on permanently very soon.

39. The radio gear will be mounted under the canopy so bore a ½-inch hole through the fuse to route the aileron servo wire from the wing saddle to the canopy area.

The front of the plane is to the left.

The TA 152 balanced perfectly with the gear laid out as shown here. The aileron servo was standard size. The throttle servo is a micro like an HS 55 or 60 - it is in the upper left of the picture. The elevator servo, lower right, is an HS 81. The battery pack is a small 350 mah pack, you can see it deep in a pocket at the upper right of the picture. The switch is the black thing at the lower left and the receiver is a FMA micro Fortress cut into a deep pocket between the switch and elevator servo. All components are accessible from the cockpit.

This arrangement worked well with the Norvel .25 engine

Balancing

40. Temporarily tape the wing onto the fuse and install the engine. The tail group should be glued in place, and the aileron servo should be done.

41. The CG --- Mark the balance point on the side of the fuse at the center of gravity, which is 2-1/2 inch from the leading edge of the wing when measured at the fuselage.  The CG is a recommended point and can be shifted fore or aft a bit. Use the battery and radio gear to adjust the balance point, and add a little weight if necessary. We used to turn the plane upside-down and teeter it on pencil points, but an easier way is to mark the side of the fuse at the balance point and poke a nail or something pointy into the doublers on each side and simply pick the plane off the table to determine if it is in balance. Shift the radio components a bit and re-try until it balances.

42. Try to make everything accessible from the canopy area. When you have determined the best positions for the servos and radio, mark a line around them and use a knife to cut the pockets in the foam. Use a gouge to dig the pockets out, and be sure to keep the fit as snug as possible. Find a convenient place for the switch. Make a hole for access to it or mount it inside the fuse using a piece of piano wire to operate it. Leave the charge cord accessible also. We usually let it hang out the crack between the fuse and the canopy. Or we have available these really trick switches with a charge jack built into them – call and ask about them.

Servo Installation

43. Thread the wires through the holes and hook up the plugs. Now is a good time to center each of the servos (you should have already tested and centered the aileron servo), and make sure of the control wire lengths. Before sliding the servos in for the final time, coat the pocket sides with silicone sealer. This will hold the servo in place, and the silicone is not too impossible to remove. Try not to get silicone on the plane because tape will not stick to it! If you do, wipe it off with mineral spirits (paint thinner).

TIP: Wrap the servo with tape so the silicone can be easily peeled off if you take the servo out. If you mount your servos externally, tape over the servos leaving the shank sticking out. We must stress again to make the servos fit snugly. If you want them to fit flush with the surface you are imbedding them in, you will have to create a pocket that is sort-of two stepped to clear the mounting flanges on the servos. This will allow the servo to sink further in and will keep the control arm as close to the fuselage as possible. Another great idea is this: If you intend to do a lot of foamie plane flying, just cut off the servo mounting flanges and sand the bumps smooth.

block the wing and weight the fuse while the glue cures - check wing alignment to make sure it is square and centered.

Note: as an option you can rubber band the wing on. Drill out the holes provided in the doublers and use 3/16 dowels.

We do not like rubber bands or break-away screws because gluing the wing on actually protects the aileron servo from damage and the plane is actually much stronger over all in the unlikely (yeah - right!) event of a mid-air collision.

Wing Installation

44. After the radio gear is planned out and the aileron servo is working properly and not binding on anything, you can glue the wing on. We recommend using Goop or E6000 (industrial version). One of the reasons we use so many layers of tape on the wing saddle and center of the wing is to keep the glue from attacking the foam. Put a dab on the wing saddle at the front and rear. Lift the flap at the front of the wing, and put a dab on the underside of it. Put the wing on and press it into the wing saddle firmly. Be sure the wing is centered and square with the fuse, then run a bead of goop along both sides where the wing and fuselage meet. We like to block the wing up and place a weight on the canopy area to hold the wing and fuse tight while the glue is curing. Let the goop cure overnight.

45. While the wing is curing, the canopy can be taped up and fit. Since the radio gear is installed, you will probably need to carve out some clearance from the underside for servos and other gear so the canopy will fit. Cover it and set it aside as it will be the last thing to install just before flying.

46. After the wing cures fit and sand the underbelly then glue it to the wing using spray or brush on glue. Cover it with packing tape.

Finishing

Well, the last things to do are install the engine, hook up the throttle, and install the canopy. You can leave the fuselage doublers to form a fake cowl or cut them off and use a suitable size round bottle. Look through the local grocery or variety store for a round straight sided storage container of about the same diameter as the fuselage. We found a storage container that fit it perfectly from K-Mart in the kitchen food storage container area. Since the bottle is clear polycarbonate, it is easy to trim openings for the cylinder head, muffler, and needle valve. Attach some little blocks (use goop or epoxy) to support the back edge at the firewall.  Screw through the cowl, blocks, and into the edge of the firewall with # 4 sheet metal screws. Now clean the inside of the plastic and scuff with steel wool before painting. Krylon works okay. It makes a pretty neat looking cowl and is very cheap and replaceable. One good tip is to use a fuel filler system to fill the tank, our combo comes with fuel dots that use a third tank line to fill. Then you won’t have to deal with the fuel lines every time you remove the cowl! 

The canopy can be painted gray or silver with Krylon spray paint and decorated with automotive pinstripe. We sometimes use ¼-inch black pinstripe to hold the canopy on around the edge, or you can tape it on with clear or colored tape and touch it up with silver paint. Some guys are gluing Popsicle sticks to the canopy and holding it down with screws.

You can decorate the plane with different tapes or decals. If you have a computer and a drawing program, make up some red circles and stick them on the wings and fuse with spray glue then tape over them with clear tape. Sand the tape with 220-grit automotive sandpaper (black wet-dry stuff) and paint with Krylon spray paint. There are a lot of tans, greens, and grays that work well. “Dull Aluminum” color makes a silver plane, but give it a couple coats of semi-gloss clear urethane before flying it. The clear is a good thing for a painted plane as it helps the paint resist the fuel. The paint will chip off a bit but take a can to the combat and touch it up between heats--works great!

The main thing is to have fun with this plane. This is designed for a .20 to .26 size 2 stroke. A 40-size engine would be outstanding, and a geared electric might work fine also. Flying is straightforward but quick! If it was built straight, it should fly great. With the CG at 2-1/2 inches from the leading edge, it will be very steady and maneuverable. If you move the CG forward a bit, it will fly rock stable. If you move the CG back from 2-1/2, it may become a bit unstable. Set your elevator to about ¼ inch up or down.

JK Aerotech   www.jkaerotech.com    Tech: 1-503-663-4081