Here's a question for you...

I've been flying one of Mike Fredrick's Bat Tricks. The plane is super, but one flying characteristic perplexes me (not a tremendously hard task). On inside loops that are not excessively tight, the plane snaps and then resumes flying. The snaps are always the same; the wings end up level, and the plane continutes flying at or above the same altitude. What I find strange, however, is that I can push a very tight outside loop without the plane snapping. I have about 9/16" elevator throws in both directions. Anyone have any suggestions, or is this just the nature of this critter?

Thanks!

Move the CG forward a little, and take some of the throw out of the elevator. If this don't solve it, I'd live with it. It sounds like a good defensive maneuver to me,,,,as long as it doesn't snap and drop into a spin.

Cajun

i fly bat tricks, all mine or the older fat symmetrical Raptor type airfoil, not the newer S8036. i have the balance point behind where the plans call for, by about 1/4 inch at least- i keep moving the wing forward/balance point back until the stalls get hairy, then move a tad back and stop. put in max elevator until the plane will just stay in continuous loops without stalling/snapping out. i found that playing with the aileron camber will make a significant difference- my planes seem to turn the tightest with the ailerons drooped a bit from neutral. the bat trick should really float in on landings, if it has poor power-off glide, try dropping you ailerons. i experiment with dropping the ailerons from neutral a turn of the clevis at a time until i find the best set=up for tightest loops. also check your wing incidence, a little positive might help. if necessary, shim under the LE of the saddle to get some positive incidence.

Thanks for the tips guys.

I actually thought it was a good defensive maneuver as well. I'll also play around with the ailerons as suggested. I did notice that the plane doesn't glide very well during landings. In fact one of the guys at the field said my plane had the glide ratio of a "man hole" cover. He even went so far as to call my plane ugly... Now that really hurt!

Thanks again!

well, they are ugly, that's a bit hard to correct. you can fancy up the tail feather shape a bit..... but they sure look pretty with a bunch of streamers hanging off them! if it glides like a brick, that is a sure sign something is wrong, either too nose heavy, incidence needs to be more positive, ailerons need to be brought down a bit, or combo of all three. the plane should float pretty well!

Looking forward to making these corrections.

Do you guys out there who fly bats have any other suggestions on performance and setup? I basically built the plane per the instructions, but I did have to cut the length of the bat down about 5" because the slots for the tail feathers were messed up.

I fly it with 40% expo and will be putting on a new .25 OS FX w/ mousse can muffler. Currently has a .25 OS FP and isn't very fast.

Looking forward to any comments.

shortening the bat is fine, it flies great shortened. use MA 9x4 prop for good speed and pull thru turns. if you have one of the older kits with the smaller fin that is about 5 by 6 inches or so, consider making the fin MUCH larger, at least twice as big, it will help counteract yaw when you get a streamer out on your wingtip. you can cut off your old fin and put on a new one, or graft another piece of coro on the top of the existing fin.

A larger fin will sometimes help with snapping as well.