High vibes from main shaft/gear/head - Trex 800e DFC Pro w/ Spirit FBL

[torpicaltrail]

New to me Trex 800e DFC Pro super combo. I've gone over it in detail, and it should be in the air, BUT...

When I run the Spirit Spectrum Analyzer (vibe test) with all blades off, it shows a nasty vibe level spike on the Y-axis starting around 1300 RPM, so I know that as the Spirit manual says, "there is a problem with the main gear, main shaft, main shaft bearings or rotor head".

Here's what I have tried:
1) replaced main shaft - no help
2) checked spindle - perfectly straight
3) In case bearing blocks were not perfectly aligned with mainshaft, I rotated main gear to tightest point (least/zero lash), then loosened screws on all bearing blocks, re-applied Loctite and carefully re-tightened the screws. Tested a LITTLE better, but still way too high.

Seller said the heli had never been crashed, and I don't see any indication of trauma. Main bearings all *seemed* good when i had it apart. OWB seems good. Disassembled the head, greased thrust bearings and reassembled (one of the thrust bearings was installed in wrong order, but was undamaged and it's good now.) Swash has a very tiny amount of lateral slop.

Any suggestions would be much appreciated.

[darknight736]

i dont own spirit, if it was the case and found nasty vibe i would try head of after that swash off. eliminate maximum component. i know vibe can be amplified by other part. if no vibe record with only mainshaft and main gear. reinstall part one a the time. not on 800 but on 500 i found wear-out swash bearing causing random vibe.

[mb-1953]

Where is the spirit mounted? What mounting tape are you using?

[torpicaltrail]

Originally Posted by mb-1953

Where is the spirit mounted? What mounting tape are you using?

I used the 3M tape that came with the Spirit.

It's mounted where the Microbeast is mounted in this picture, with pins toward the back.



Thanks

[torpicaltrail]

Originally Posted by darknight736

i dont own spirit, if it was the case and found nasty vibe i would try head of after that swash off. eliminate maximum component. i know vibe can be amplified by other part. if no vibe record with only mainshaft and main gear. reinstall part one a the time. not on 800 but on 500 i found wear-out swash bearing causing random vibe.

I will try removing the head and swash and test. Also ordered main bearings. Will report back. Thank you.