So I opened up the sealed box I'd gotten off E-Bay thinking that I'd get ready for a building project. I expected a nice kit, and so it is. However I'm not certain, but it seems like the empennage balsa and the ply ribs and riblets are a bit porky. In addition, the fuselage is 1/2" thick balsa (!). I'm "heavily" impressed, but I do like to build light whenever possible.
I've got two options involving four engines for this kit. One would be to build it as a high risk trainer to supplement the Cartier foam wing Rugged Stunt Trainer / OS-20FP that I dearly enjoy. That way when RST augers in, I can pull another trainer right out of the car and carry on. The engine choices would be another OS FP-20, and OS LA-25, or an OS FP-35.
The second option is a little offbeat. I could build this kit as more of a sport and mild stunt "showplane," using a Black Knight Saito .30 for power. I've a nifty color scheme in mind. Ideally, I'd be able to fly it over a large grass field in a public park located very near my house. Both options would require standard, 2-piece landing gear.
I realize that I'm not giving you folks here much to go on regarding my impression of the heavy kit parts. I can always just suck it up, flip a coin and build something. Ha! However if you've got any suggestions, let me know.
Built out of the kit, it will end up about 36 ounces with a 20FP, which is perfectly acceptable for training purposes. You will have to limit the corner a bit to keep it out of trouble in hot conditions, however. Power is not an issue, wing loading might be. All my early experiments, including the one where I switched from a Larry Foster Fox 35 to 20FP and found that gravity appeared to have been cancelled, were with a completely stock model.
A 1/2" thick balsa fuselage is absolutely standard stuff for "35-sized" model, and the doubler arrangement is far superior to older vintage models. And it's pretty small in profile, too. However, the plywood and spruce wing is not standard. It flies OK at 36 ounces. The problem is durability, mine completely shattered in the first crash, so does does everyone else's.
My suggestion is to go ahead and build it as shown, then use the plans to build a second model, fuselage and tail the same, but the wing with 3/32" medium balsa ribs at each position. Where there are plywood half-ribs, make a full rib of 3/32 medium balsa. 3/32 medium balsa center section and trailing edge top and bottom, 1/8x1/2 hard balsa, or 1/4x1/4 hard balsa spar. Medium 1/2x1/2 balsa leading edge. Airfoil as shown on plans, no real aerodynamic changes. Cover with Ultracote on wing and tail surfaces. Put on one coat of thinned Timbermate wood filler on the fuse, sand off, prime heavily with Superpoxy of Klass-Kote "fast" primer, sand, then 2-part epoxy paint on fuselage.
Only aerodynamic change is to remove all rudder offset, do not airfoil it, measure it to be sure it is exactly straight ahead. Mechanically, add adjustable tip weight box in outboard wing tip, and if desired, an adjustable leadout guide. Start with leadouts about 2" from LE, and CG about 1" from LE.
Trim is as described here, including tip weight to start as indicated using "counterweight method":
http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=198043&mesg_id=198043&listing_type=search Stock controls as shown on plans are OK.
This will fly slightly better at about 29-30 ounces with a 20FP or 25LA, but will withstand crashes much better, as long as you are on dirt/grass.
Brett