Hi,
I noticed recently that Top Flight has re-issued their .60 size AT-6. I built one a few years ago, and still enjoy flying it. Mine is modeled after a Harvard from Canada. I have been repairing it the last few days, after a minor crash at the field the other day. There are a couple of things I would do on my next one that I would pass on to someone building one today.
- On the wing saddle of the fuselage I would suggest using 1/16" ply instead of the kit balsa, at least on the forward section. I like to rest the wing on the saddle to make my servo and retract connections. The thin balsa gets punched out if I am not careful with the LE wing dowels while doing this task. I have even stuck my fat thumb through it during handling.
- I used Foremost Products, Medium Fillet #129, a plastic strip that creates an instant fillet between the wing and fuselage. Mount the wing with some wax paper between the fuselage and lay the fillet down. Mark where it goes and remove some of the covering to allow the glue to hold. Start at the TE and work forward. Spot glue with CA to get it started and use a heat gun to mold the material close to the wing as you go, adding more spot glue along the way. It will even follow the curve all the way under the LE (use heat). You will have to trim the ends of it where it meets the center of the wing, under the fuselage. Go back and use thin CA to glue all of it down close to the wing. This has been a very durable arraignment, the material holds paint very well (be sure to scuff it with sandpaper first). I am very glad I opted for this method, it has served very well.
- Beef up the forward rails of the landing gear mounts for the retracts. Not the whole mount, just the rail where the screws go. It is better to rip the gear out than to take out the whole wing in a hard landing, but a normal landing on a grass field may tear the screws out of the stock rail.
- I would use balsa blocks, rather than sheet stock between the firewall and the foremost plywood cowl ring where the cowl mounting blocks are glued on. This will prevent the mounting blocks from twisting off in a minor, low speed impact; like the tip stall take-off I performed a few weeks ago. If I had beefed up this region originally, I would have less repair work now. Be careful not to add thickness where it is not needed. Depending on your choice of engine, it can be a tight fit near the cowl ring and outside skin.
This model looks great, and flies even better than it looks. It is worth the effort to make this a sport scale model. I get a lot of compliments on it. Mine has an O.S. .60 FX, which is plenty of power.
Tom