Starter shaft feels snug

[Taxus812]

How tight is your starter shaft on you X50?

Is it super easy to turn it when going clock wise ? Mine seems tight. I pulled it and its not bent, I tried a clutch and the bearings with no motor installed spun super clean.

I am troubleshooting a loud whine I herd when I was hovering. I cant figure out where it came from. Took off had got a bad wag I assumed it was vibs. Then I heard a loud squeal like a gear stripped. Quick land and did an inspection. I took the blades off and started it up. (No squeal but no load either)


This is all I can find the starter shaft feels a little tight to turn clockwise.

Stumped ?

[Don S]

Probably rubbing on the end of the crankshaft.

Or it's bent.

[Taxus812]

Was thinking the same but when I pulled the starter cup off and I can get some up down play.

I also rolled the shaft on a flat surface and cant see a bend at all.

I am wondering if the motor mount got tweaked a bit.
However I wanted to know how loose others are to see if im chasing my tail

[Don S]

Clutch bearing?

[Taxus812]

Replaced the clutch to make sure but I did discover that the one way bearing on the clutch is not a smooth easy turning bearing. I checked it against a new one and an old one. Both are the same. I think that is a major contributor.

Now I just need someone with an x50 to turn their starter shaft by hand clockwise and let me know if it is silky smooth free spinning or if there is some light friction

[Don S]

My bad. Mine spins with minimal friction. Not butter smooth, but pretty much effortless.

[Taxus812]

Thanks for the feedback. I think I have something slightly out of alignment. If I press on the front motor bearing I can turn the starter shaft almost effortlessly. If I release pressure it goes back to having some resistance. Im going to check the motor bolts If I remember I had a small amount of play before tightening them. Perhaps they got bumped.

[Taxus812]

The motor bust have gotten a bump and was tweaked out of alignment. I loosened the bolts on the engine and pushed the motor until the starter shaft was smooth and not binding. Then I retightened them. It is actually very smooth now (close to effortless)

I have to pull the them one at a time ,re-loctight and fix my governor sensor now but at least I know what needs to be done.

Hopefully that was the source of the squeal and the vibes

[skytrekin]

Make sure your starter shaft is not rubbing on the end of the crankshaft.
When I built mine, it was rubbing on the crankshaft. After taking off about 1/8 in off the end problem solved and no more rubbing or vibes.

Their are pictures in the X50F thread where I talk about this solution.

[Taxus812]

First thing I checked . If I loosen the starter cup I have up/down play in the shaft. So no rubbing.

My issue was the motor was slightly out of alignment (tweaked to the left ever so slightly) . I had rebuilt the motor recently, must have bumped it and didn't detect the misalignment

The starter shaft turns almost effortless now

[Don S]

I didn't think the engine mount allowed play? Is it time for a new mount?

[Taxus812]

Possibly.
This is what I observed. If someone is pulling their motor out soon let me know if you see the same.

The 4 bolt holes on the engine do allow for very small amount of movement due to the size of the holes vs. the bolt size (.25mm would be generous). If you twist the engine slightly on the mount, that translates to more at the front engine at the starter shaft. This is not enough to keep the engine from installing or even running, but enough to put some pressure on the one way bearing and starter shaft. (as well as misalign)

This was causing my starter shaft to feel "snug" when turned by hand. It is also the likely source of the squeal I heard.

What happened ?
I recently rebuilt my motor (new bearings, Fan, clutch, etc). I also installed a new governor sensor. This required me to pull the motor off the mount. When reinstalled It must have been slightly off. So when I was doing my test hover It got a vibe and squeal a few min into the flight. In the hunt for what the hell as was that . I discovered the starter shaft felt snug and was most likely spinning hard in flight.

(Note: The motor mount itself in the frame has no give BTW. )

[Vaeloron]

This happened to me once and it was actually because the clutch was coming loose. Looks like you figured it out though.