Thanks guys......Brett, excuse my ignorance....I'm just getting back into control line after over fifty years but I like your suggestion about making the flaps removable. Could you give me instructions on how to do that please?
Remove all the pins on the hinges, and replace them with a single really long hinge pin that goes through all of the hinges. Normally on the large hinge, the pin is 1/32 in diameter, use a 1/32 wire to install them, then, once the glue is set, replace the pin with a .025 diameter pin for flight. Put a bend in the end and use clear tape it to the wingtip to keep it from falling out. If you want to alter the flaps, remove the tape, pull out the pin, then make a new flap using the current hinge positions.
Note that the hole where the flap horn goes into the flap can't be glued, otherwise, you can't get it off. Just make it a tight slip fit.
I show mine in this thread:
https://stunthanger.com/smf/building-techniques/removable-flaps/msg630594/#msg630594 The reason is that this is a pretty simple modification (as opposed to some of the re-engineering ideas that might have some merit but are much more complex) that allows you to address the issue with the excessively large flaps without having to cut up the airplane. Note that I am pretty much 100% certain, having dealt with this issue on several occasions, that the flaps are much too large for the airplane. This allows you to fix it without taking a knife to a completed airplane. We have had to do this several times, including to the 2006 Senior National Champion Paul Ferrell - we cut 3/4" off the flap chord about a week before the NATs, it immediately fixed all the problems he had, and he won against some real competition.
Of course, building it as shown, then cutting it if necessary, is still an option. But the removable flap thing is so easy and so convenient for a variety of reasons that it seems like a good modification to do in any case.
BTW, the idea behind the large flap is that it gives you "more lift". I think it has more to do with the noiproblem with the excessive flap is that it inhibits the pitching motion of the airplane. The tail is extremely large to overcome this effect. The combination has the effect of requiring a lot of control force to get the turn started, but when you reach some amount of deflection, the turn suddenly tightens up. The results is a sort of "explosion" corner that can be very difficult to control.
Cutting the flaps down, or using smaller flaps, greatly reduces this effect (and not coincidentally makes the arrangement much more like other more successful stunt planes) and makes it much more predictable and take much less effort to fly.
Brett