550:Rough spot on gears

[bbagle1]

I received my 550 today from flying hobby. Got the CF version with a metal head. It came assembled with the plastic head on it and when I spin the head I feel a rough spot in the gears. I looked and could not see anything obvious but at the same spot on each revolution there is a noticeable amount of resistance.

I thought I read about someone else with this problem but I can't seem to find it. Any ideas on what might be the problem and how to fix it? I am very new to heli's so talk please explain it like you would to a child:oops:

[Phoinix]

Before flying any RTF helicopter, you should take it apart for getting to know your helicopter and to check for such kind of problems.

What you described can be anything from bent main shaft to bearings.

[mjdee14]

You will need to try and isolate which two gears are causing the problem....if it's not obvious then loosen the bearing blocks and for each shaft and rotate, sometimes there is enough give in the holes to repostion the gears and maybe get rid of the resistance.

Make sure it's not the motor pinion....move the motor back.

I think somewhere in the instructions it says to adjust to the high point, and as long as you have good contact on the rest of the circumference you should be ok....

[Mikej]

One other thing that might be worth checking - is the swash parpendicular to the mainshaft, if not and the head is tight you will feel extra "tightness" as the shaft turns - your best bet would be remove motor and head (but leave shaft in first gear) and then add bits and pieces until the problem appears.

Good luck,
Mike.

[bbagle1]

I haven't been able to take it apart yet but it looks as though the problem is the gear mesh between the main gear and the tail drive gear. There is a very small gap between the two gears throughout the revolution then the gears completely mesh on the rough spot. Is it possible that the main gear was not machined true or that it is not perfectly centered on the main shaft? The problem has to be with the main gear as it happens at the same spot each time but I would like some help as to what may be the problem. Thanks to everyone for the help you have already given me and I'm sure will give me in the future.