Finishing up an Alpha 60 RTF and was doing the CG check, which Hangar 9 says is 4 1/4" from leading edge. So far I have almost 14 OZ of lead in the tail, and it is still a little nose heavy.[X(] Is this usual? I double checked the reciever/battery and it is in the stock location, just in front of the servos. This seems really unusual for an RTF( a lot more than the kits I've built), but since it's my first RTF, wasn't sure if anybody else ran into this.

Any help would be much appreciated.

Thanks,
NCDaveD

somethings not right, no way should you have to add that much(or any weight)

im sitting here thinking and there is no way, dont know what to tell ya except dont fly it till ya find out whats wrong

all my H9 trainers balanced right on(alpha40 and arrow40)

keep looking[&:]

your not balancing it with a full fuel tank are you?

Nope, no fuel in tank. Unit was built according to the directions (what little building there is). That's why I'm so confused on this. So far I have 2 ARFs and 2 kits (working on kit #3-Venture 60) under my belt with great success...no cg issues there. Is it possible they missed on the CG by a bit? The 4 1/4 back from the LE is about 1/2" back from the front spar, about 1/3 of the wing chord (I believe). Only thing I can think of is the weight of the flywheel on the motor(thats a hefty chunk of lead), but figured Hangar would have accounted for this in thier calculations.

Will go back and see how much moving battery behind servos help.

Keep those thoughts coming please!

NCDaveD

OK, swapped position of battery and reciever...big change. With 6 oz in tail, nose is about 15 degrees down (jury-rigged protractor setup ). Much better than what we had before. This seems better (although I like to get slightly nose down w/no lead if possible).

Would it be safe to ge the planes maiden flight with this configuration and see how she flys before adding more weight/shifting battery further?

Thanks in advance!

NCDaveD

so where is your CG? somewhere around 3.5?

3.25 on the nose! Sorry for the delay, but had to start it up outside before rains came (just got a little wet). 6 oz in the tail (2 -3 oz sticks on top of each other in the tail). Almost forgot to balance laterally...doh, so will do that now before we put the wieghts in with double sided tape. I figure when the flywheel is pulled off, all the weight will have to come back out, but that will be in the future when the owner is ready.

Think that 3.25 is OK?

NCDaveD

This is sooooo embarassing....

Turns out what I thought were 1 oz weights were 1/4 oz weights. So instead of 6 oz of weight, it was 1 1/2 oz.

Oh man.....

It did take .6 oz to balance laterally (left wing to offset muffler weight).

So looks like the problem isn't as bad as I thought. I apologize for waisting everybody's time []

NCDaveD

HeeHee, done the same thing myself, dont feel bad, and i do think it will fly ok, just might come in a little hot though

Whats a good prop to put on an alpha 40,after my pts p51 prop disintegrated in mid air i dont want to use the same prop on the alpha 40,i have a 10x6 on my pulse xt 40

10x6 will be good

Thanks Gary,I go to extreme omnn my staudaucher and run a 15x6 with the os 1.20