Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
introduction:
It's gettin' to be that time of year: building time and to start thinking about Spring! I've decided to start building the AT-6 first. I want to start this plane since it's simpler to build than the Yellow's P-40 and P-38: no inner doors and no retractable tail wheel. I read the instructions and she will build similar to the P-40 & P-38: ie, sheeted wings, horizontal stab, FG fuse and lots of FG parts.
pic 1-6: The full size plans are included: one of the fuse and one of the wing/tail feathers. An instruction booklet is also included. The plans are full size also for building the rudder and elevator with the provided pre-cut balsa.
pic 7/8: The wing is three piece. The outer wings presheeted and the inner FG wing will stay attached to the fuse so only each aileron wire will needed to be connected out at the field. Two or three air tanks will be put in the wing along with the air valve for the main retracts. No retractable tail wheel so everything can stay in the wing.
pic 9: The fuse looks pretty clean and I didn't see any pin holes (but there's always a few to fill in after putting on the primer).
pic 10: Lots of wood and FG parts for the rudder and elevator plus the cockpit tubs and a nice FG canopy frame.
pic 11: Nice FG gear doors.
pic 12: Plans say a G-62 would work but I'm using a 3W-75 (especially since I already had it!). Also a 40 oz tank and Yellow's spinner. Plan to also add smoke (gotta' have smoke in an AT-6!).
< Message edited by samparfitt -- 12/19/2007 11:39:57 PM >
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
introduction (cont);
pic 1: A very heavy cast dummy radial from Ziroli. This plane will need nose weight anyway (another good reason to use a bigger engine!).
pic 2: A Bob Dively AT-6 cockpit kit, a nice FG removable antenna and a nice FG cowl with mounting bracket so mounting will be internal with no bolts showing on the outside. A roll of Ziroli 1 oz FG cloth.
pic 3: Robart main retracts and non-retractable tail wheel plus all the servos needed.
pic 4: Pre-sheeted horizontal stab.
Stats is 101" WS. Says should weigh about 27 lbs. I'm guessing closer to low 30's.
< Message edited by samparfitt -- 12/20/2007 12:22:48 AM >
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
RETRACTS:
pic 1: I used Robarts instead of Yellows retracts so I needed to modify the retract mount. The pencil line is all the material that needs removing. I already had the Robarts from a previous Ziroli AT-6 (balsa heaven!) but I would recommend the Yellows to save on all the work. The mount needed to be wider and, initially, I was going to remove an equal amount from both sides. Fortunately, I check the angle of the strut and all the material needs to be removed from the back mount. The bottom of the rib also had to have some material removed.
pic 2: Here's after all the material has been removed and the blind nuts are being installed. I center punched the holes, pilot drilled a 1/16" hole and used a final 11/64" bit to drill the final hole for the bolts. I used great planes (GPMQ3028) 6-32 X 1/2" socket head screws and Dubro (607) 6-32 blind nuts. As you can see, round holes had to be made along the front of the FG so the socket head screws could be put in.
pic 3: More material had to be removed from the back of the mount to allow the strut to close. I had to cut all the way through this part of the mount but I don't think it'll weaken the mount. The force is fore and aft and the mount is all very heavy duty 13 ply 7/16" thick ply. There is room above the mount to epoxy some ply to bridge that open spot.
pic 4/5: up/down position.
pic 6: tools needed to modify the retract mounts.
< Message edited by samparfitt -- 12/20/2007 5:20:16 PM >
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
Post pictures when you have time.
Outer wings:
pic 1/2: The inner side of the flap well has to be removed and sanded. Before/after.
pic 3/4: The outer side of the flap well has rounded corners that have to squared away. Before/after
pic 5: I put the 1/64" thick ply in the flap well and used a thin piece of brass to get a line parallel to the right edge of the flap well. After cutting along the line, the ply will be snug against the side of the flap well.
pic 6: The ply on the bottom and a 7/16" thick piece of balsa goes against the LE of the flap well.
pic 7: ply and balsa epoxied into the flap well. Lots of weights to keep the wing as well as the ply flat.
pic 8/9: The aileron comes with two cuts into the wing. We finish cutting along the front to remove the aileron and then finish removing the second cut (which is waste material). Before/after.
pic 10: A 7/16" thick piece of balsa is epoxied to the TE of the wing where the aileron goes plus a triangular piece of balsa is epoxied to the edge of the outer flap well.
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
Outer wings (cont) Sanding the outer wings and ailerons is next. I tape around all the areas that I will be sanding to prevent damage to the existing balsa sheeting. Using power tools and even hand tools agressively can do a lot of damage quickly to areas that you don't want to sand. (power tools allows you to make mistakes much more quickly!). The LE and TE of the wings need sanding as well as around the flap wells. Also, the LE of the ailerons need to be sanded to a half circle radius plus sanding all the end blocks that were previously added.
pic 1/2: Using a radius bit on my table router, I can quickly remove the excess balsa off the LE of the ailerons. This gives me the basic radius when I begin hand sanding.
pic 3: A flush cutting saw (at HD) is also good at removing excess wood. An assortment of paint sticks with different grades of sand paper glued to them make good sanding sticks.
pic 4/5: Ridged at HD makes a nice oscillating sander that also comes with an oscillating belt sander. Also good for quickly removing waste material. Different hand orbital sanders are also good for this.
pic 6/7: I manually used a long drill bit to put a hole down the ends of the outer wings to the aileron servo tray so I can, later, add navigation lights. Some compressed air does a good job of removing all those little white balls from the hole and wing.
pic 8: The LE sanding done.
pic 9: Ailerons sanded as well as the flap well areas.
All this sanding kicks up a lot of dust. I'm presently building the plane in the warm basement but go to the detached shop for any serious sanding to keep all that dust outside. Some small planes (cutting type!) are also good for removing bulk material without creating any dust.
< Message edited by samparfitt -- 12/21/2007 4:43:52 PM >
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
outer wings (cont)
pic 1: Some 1/64" thick scrap ply epoxied to the end of the wings so the wing tips will be secure when they are epoxied on. Holes put in the ply to match the wing tips.
pic 2: Wing tips epoxied on (I used Zap-a-Dap). Strung some radio shack #22 gauge flexible wire for the nav lights.
pic 3: CA'ed the triangular stock to the TE of the wing where the ailerons are attached.
pic 4/5: Flaps and ailerons re-sanded so everything fits in the wing.
pic 6: I used some Evercoat Easy Sand (2 part mix) to smooth any problem areas before glassing.
< Message edited by samparfitt -- 12/21/2007 11:06:50 PM >
Posts: 1740
Joined: 9/1/2002 From: West Chester, OH, USA Status: online
outer wings (cont) Tonight, I got one more thing done.
pic 1: I used Robarts large (grey) hinges on the ailerons and small (black) hinges on the flaps. The flaps are too thin for the larger hinges. I made 'V' cuts so the hinge pin will be at the center of the radius of the ailerons LE.
pic 2: Aileron dry fitted.
pic 3: Flaps dry fitted.
pic 4: Flap and aileron deployed. Four hinges in each movable surface.
< Message edited by samparfitt -- 12/22/2007 2:24:46 AM >
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YELLOW AT-6 TEXAN BUILD THREAD - 
