CG ?

[franknsled]

I moved the Beastx to the gyro platform(because,at the time, I didn't have a clue what I was doing with a cp heli) so it was easier to program. I think between that and a sticky elev servo I crashed it. So I put it in the box and tried a 450 3d. Got that pretty much figured out after numerous rebuilds. Figured I new enough to get the 300 out again. Repaired the damage and reprogrammed the Bx. Checked the CG and it takes 25 grams on the front to get this thing to balance? WTH?

[Nelsonisms]

The 300 is notoriously tail heavy regardless of where the AR7200BX is mounted. People have solved it a number of ways. Scoot the battery and ESC as far forward as you can. A bigger battery is always a good option as it's not totally dead weight. Maybe consider a fiberglass canopy to add some weight to the nose. Mine is pretty good now, but it's a full Lynx frame and 4S power system.

[franknsled]

Thanks. Good to know its not just me. If I put 20 grams in the nose of the canopy, it balances perfectly. I'll look at some canopies. Can I get a bigger 3s battery to fit in the canopy?

[Nelsonisms]

Some people have had good luck with 1500mAh packs. You may need to move the grommet holes back a little depending on whichever canopy you use.

[vtown nick]

A fiberglass canopy is 40g if I remember correctly. That alone can help.

[Mordecai]

I read that achieving a perfect balance was not as critical with flybarless helis, is that correct?

[Nelsonisms]

Originally Posted by Mordecai

I read that achieving a perfect balance was not as critical with flybarless helis, is that correct?

Maybe not AS critical, but it's still important. A tail heavy FBL heli will still want to drift backwards and will be less predictable in 3D maneuvers. For peak performance you still want it to be as balanced as possible.

[DoubleCH]

It's like driving a car with bad wheel alignment that always pulls the steering wheel to one side when going straight. You can still drive the car straight on the roads by constantly yanking the wheel the opposite way, but it'll put more stress on the control system (the driver in the car's case, and cyclic servos, etc. in the heli's case).

[Mordecai]

Ah ok, cool. I was contemplating going up to a higher mAh pack but might start with a fibreglass canopy and see what that does. I tried moving my 1350 pack forward so it was halfway off the battery tray but that didn't seem to help much and the canopy holes would have had to be relocated!

[DoubleCH]

I fly nanotech 3S 25C 1500 pack. They are just a tiny bit heavier than stock 1350 so I have to mount the battery further forward to balance CG for the metal tail grip assembly and stock light plastic canopy. I drilled a 2nd set of holes on the canopy so I can mount the much longer than stock 1500 battery further forward.

This is how far forward I mount my battery.
https://www.helifreak.com/showpost.p...&postcount=522

EDIT: Here's how far forward I mount the stock canopy. Notice the canopy mounting pole holes. Stock one is above the number "3" while the new one is above the 2nd "0".
https://www.helifreak.com/showpost.p...&postcount=376

[Mordecai]

Good stuff. I'm digging the ghetto tail fins. It's surprising how heavy the cf fins are hey.