550U Build issues

[Rockarruda]

Hello All,

I am getting pretty frustrated trying to finish my 550U which is 90% done. Went together pretty well until I put the main gear assembly in found that it wobbles vertically enough to hit and run on the belt.

Called up Prostar and Adam sent me out a new main gear thinking that was warped. Get the new gear in and it still wobled, so then I looked at the autorotation hub, and that seemed to be the source of the wobble. I ordered a new hub with bearing and got that in yesterday. Low and behold, the wobble is now WORSE!! The one way bearing is the problem in the new hub and is causing the whole assembly to wobble badly. It seems the one way bearing is off center WTF!!

So my 550U has now sat on my table waiting to be finished for a little more than 2 weeks now. Has anyone had this problem with the 6HVU/550U main gear assembly? Now I am at my wits end and a bit frustrated as I am so close to finishing this build but have been stuck trying to remedy this wobble in the assembly...

[Lighty]

Sorry to hear your troubles. My main gear on the 6ULT was hitting the belt as I spun the gear after a rebuild.
I found that I did not have the hub fully pressed into the main gear. It had to click in. Maybe this is the cause, you might think its seated but it might not be..

[cyclo]

Originally Posted by Rockarruda

Hello All,

I am getting pretty frustrated trying to finish my 550U which is 90% done. Went together pretty well until I put the main gear assembly in found that it wobbles vertically enough to hit and run on the belt.

Called up Prostar and Adam sent me out a new main gear thinking that was warped. Get the new gear in and it still wobled, so then I looked at the autorotation hub, and that seemed to be the source of the wobble. I ordered a new hub with bearing and got that in yesterday. Low and behold, the wobble is now WORSE!! The one way bearing is the problem in the new hub and is causing the whole assembly to wobble badly. It seems the one way bearing is off center WTF!!

So my 550U has now sat on my table waiting to be finished for a little more than 2 weeks now. Has anyone had this problem with the 6HVU/550U main gear assembly? Now I am at my wits end and a bit frustrated as I am so close to finishing this build but have been stuck trying to remedy this wobble in the assembly... Another call and another week of waiting....

Talk me off the ledge....

Rockarruda check this post of mine in the 7HV forums: https://www.helifreak.com/showpost.p...&postcount=250

I noticed that the main gear was not mating flat against the belt pulley which was potentially causing the pulley to wobble. Also there were reports of the pulley cracking and I suspect it was because it was not fully flat to the main gear.

The mod I did fixed the wobble. I am now fixing an issue with my tail hub on the 7HV which I suspect is contributing to tail vibes I am having at high FFF. IMHO Compass needs to improve the QA on their parts or those who are not as OCD/meticulous on their builds might end up frustrated.