N

N316RV

Well Known Member
I am mounting the spinner on my -9A. I have a new Hartzell CS prop. I checked the run out near the front of the spinner with a dial indicator before drilling any holes. It was .075". I started looking for the source of the error. The front of the prop hub is less than .005" TIR. The front spinner bulkhead has around .050" run out. The four bolts that secure the bulkhead to the prop hub are a snug fit. I called Van's and they seemed to think .075" run out near the front of the spinner was ok. That seems kind of high to me. What kind of guide lines have others used?
Thanks
Alan Jackson
Hartselle, AL
 
Personally I strive for less than 1/16" (.063) run-out.
However, I've seen fiberglass spinners with up to 1/4" run for years without problems.
 
Alan, try rotating your front bulkhead on the prop to 90, then 180 degrees from the current position, measuring each time. If it stays at 0.050" I'd ask for an exchange.

Also lightly sand the inside of the spinner to eliminate any lumps or high spots where the bulkhead might sit.
 
Thinking outside the box

Sometimes it just takes a suggestion from someone else (thanks Mel and Dan) to get you thinking outside the box. First the confession - the part number sticker was still on the back and it was between the prop hub and bulkhead. Also noticed that the disk was not flat. Flattened it out and put it back together. Front flange ran much trurer. Total run out at front of spinner went from .075" to .022". Good enough. Ready to drill.

Alan Jackson
Hartselle, AL
 
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