CG problems
 

my second plane build is the tower trainer 40. my first (from scratch) was a SIG KADET SENIOR.i had no problem with its center of gravity. now it looks like the TOWER TRAINER 40 needs about 2 ozs at the tail or about 6 ozs right behind the servos to get it balanced. is this right??the tower 40 was a ARF. could this be the problem? please help. if you have any more questions please ask. THANKS

RE: CG problems
 

It is quite possible that it needs this much weight.

Before adding any weight, move the receiver and battery as far to the rear as possible (use a 6" HEAVY DUTY extension for the battery if needed ). You may also want to consider going to a larger battery (1800 - 2200 mah ). My personal feeling is that if I have to add weight, I try to make as much of as possible "useable weight".

To secure the battery, use industrial strength self adhesive velcro. Wrap the foam around the battery with some masking tape and attach 2 strips of the velcro to the masking tape. Next, remove the velco from the part attached to the battery and LIGHTLY readhere the 2 pieces. Peel the backing off the other half and lightly press in place. Now, using a flat blade screw driver, hold the part attached to the fuselage down while you remove the battery.

Next, press the velcro against the fuselage firmly and wick some thin CA between the velcro strip and the wood in the fuselage. (the adhesive when used against wood, tends to loose its grip in a short time. The CA insures it stays put.) When the CA is dry, press the battery in place on the velcro strips. (The battery WILL stay put even through hard crashes ).

Now rebalance the plane. If you positioned the battery correctly, you should need little, if any, additional weight.

RE: CG problems
 

THANKS but i already have the batt as far back as possible.the way this ARF was made i can't get my fat hands in far enought to move the batt any more unless i cut out some of the factory monocote. sooner or later i'll end up crashing it thats when i'll screw around with the covering. thanks for your suggestion!

RE: CG problems
 

The less extra weight you add, the better it will fly, use the 2 oz's at the tail.

RE: CG problems
 

What method of balancing do you recommend?? Please be specific as I hear of varous ways to get to the same end point..Thanks

RE: CG problems
 

If you can't get yoru hands in the fuse why dont cut covering out and then re apply it back on?Just put the battery on top of the fuse and balance the model,then mark the position of battery and cut the covering,install the battery inside and either iron covering back on or make a patch.If you do it on the bottom of the fuse it won't be noticable while model is on the ground...and in the air..who cares,nobody will be able to see.
I never built tower hobbies 40 but i owned one.The guy i bought it from had a little door cut in the bottom of the fuselage and he had like a tiny door which was held in place with tiny servo screws.

Try it.