500 3D Belt Main Drive Pulley Backlash

[rwharrisjr]

After about 100 flights I have about 5 to 10 degrees of backlash between the main rotor shaft and the large belt drive pulley. It appeaers that the slot in the pulley that engages the drive pin has worn a bit. Has anyone else encountered this before or know what an un-acceptable amount of backlash may be? Heli flies just like it always has.

Thanks,

Rick.

[LITHIUMSTATIC]

I've never heard of that before.... Just curious, how hard do you fly it? Have you taken it apart and looked at it?

[rwharrisjr]

I've never heard of that before.... Just curious, how hard do you fly it? Have you taken it apart and looked at it?

Sport flying, mild aerobatics. Pin is tight in the shaft but slot is slightly worn.

[helicraze]

I wouldn't worry, the belt teeth do not exactely match the pulley above the main gear, it can slip back and forth a MM

[dahld]

I'd hate to say "don't worry about it", and then have the slot that captures the pin tear out from the gear for some unexplainable reason. But I have a Logo 600 (same pin and gear) that has been flown pretty hard 3D for over 200 flights now, and so far so good. Yes, some play has developed (like you said, 5-10 degrees), but I've looked at it recently, and it didn't look bad at all. Not enough for me to worry about, so, I'll say "don't worry about it".

Take care, Dave Dahl.

[billyd]

The pulley is easily replaced, buy a new one with a new pin and replace them. There is no point in flying something with an issue. It's a few dollars and 5 minutes of work.

I am a perfectionist, that would drive me crazy just knowing it's there.

[t-rexn8]

Yeah if you are pushing the heli really hard you may want to replace it as cheap insurance. The new drive pullies have more material around the pin slot as well.

[rwharrisjr]

Thanks, everyone.
I am ordering a new pulley. I will continue flying on the old one but check it out after each flight!!
Rick

[OICU812]

Yes do order and install the newest style, the newest style have allot more material around the pin area indeed.

[helicraze]

Anyone got a pic of new and old?

[t-rexn8]

I will see what I can do.

[rwharrisjr]

Here is a picture of the old style main belt drive pulley and the new style. The old pulley could probably have gone many more flights, but having the new one is worth the peace of mind.