ACME 380 prop vibration at 3300-3500 rpm?

[Miljack]

I just installed an Acme 380 (13.5" x 17.5") prop on our ProAir, and I have picked up a vibration from 3300rpm-3500rpm.
I believe prop is installed correctly, nut torqued ok. The OJ that I had on there before worked ok, no vibratiion or noise, however the OJ was on soooo tight that I had a hard time getting the prop puller in between the strut and the prop. Could this have caused a problem? Do I need to take scoth brite to the shaft where the old prop was installed?

thanks,
Jack

[Mikeski]

RE: ACME 380 prop vibration at 3300-3500 rpm?

Make sure the square key is not too tall for the new prop, this is a common cause of new prop vibrations, it causes the prop to run out of round.

[Miljack]

Mike,
Very good point. I didn't do the prop on, mark shaft, and install again with key. The key does have the "retaining" pin, but I know that doesn't make it fit for all apps. I'll have to take it off, and try again.

thanks,
Jack