Heliguy Forum - RC heli forum

Hi

After my second 35MHz 4 in 1 went haywire (gyro I think) I decided to order a 2.4GHz 4 in 1, same as is in the A and B models. This dropped through the door today, and at first it seemed like a straight swap. Removed the old 4 in 1, plugged in the new one and it powered up fine. Quick check to see the servos moved as they should, and all seemed well.

I tried to punch it up into the air from the coffee table, but it just span off and onto the floor. Holding the heli in my hand I thought it was lacking headspeed. I still use the old short motors in this heli as I still have a couple spare. Briefly wondered how the motor could have died with the heli just sitting there, then without further ado, swapped the motor for a new one. Tried taking off from the coffee table again, same result.

It took me a couple of minutes to realise the blades were actually going THE WRONG WAY! I still can't work out why, but anyway un-soldered the wires from the top of the motor and swapped them over. Now at least it would take off but wanted to go violently left and smack the wall. I ended up lengthening the aileron servo rod a whole 2 turns, this was trimmed ok with the 35MHz 4 in 1, so I guess the GHz 4 in 1 centres the servo in a different position.

Some further trimming later, and it now hovers perfectly. The tail was always an issue before, but it is now just as steady as the A and B. For some reason the rudder requires full left trim, and even then still requires a tiny amount of rudder input to hold it steady. I've never been too fussy with rudders being perfectly trimmed anyway, and am happy enough with the way it is.

I've always thought the original 4#3 hovers better than the A and B, and confirmed this to myself today. (That is once it's trimmed perfectly, an untrimmed A or B is much easier to handle than an untrimmed 4#3). Once it is well trimmed, holding this in a stable hover definitely requires less cyclic input than with the A and B. Might be to do with the slightly higher headspeed I'm not sure. Also the A and B suffer from TBE more than this does.

Although the A and B are so much better at actually flying around, this is still a good heli in it's own right. Further inspection revealed that when I manually move one of the servos, there is a definite indication of broken teeth. Although when it is moved by the cyclic it seems ok, even with me pressing gently on the servo arm against the movement. Still something is not quite right, so next thing is a couple of servos and I'm going to try the new A and B version servos since they seem to move more smoothly. Hopefully this will make it fly more like the A and B. Probably won't be a straight swap as they're different sizes but I'm sure I'll make them fit.

Another thing I'll get while I'm at it is a 4#3A upgrade set, i.e. shaft, swash, blade holders etc. but stick with the old style blades for the increased headspeed. Also I'll probably just stick a new long-can motor in it for the extra power, it does seem lacking particularly when compared to my new A which is like a rocket-ship. I reckon the more powerful motor may help with the rudder trim problem too, since it is left trim it requires, if it were right I'd replace the tail motor.

Will post back when I get the more new bits, and meantime can anyone think of why I had to reverse polarity on the motor?

Cheers
Dusty
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Cheers,
Dusty

Blade 400 3D
HBK2 3900 brushless, Superskids
HBFP 380 motor, M24 blades, DD tail, Super/King2 skids
Walkera 4#3, 4#3A, 4#3B, 4G3
Lama V3