What do you do to get a back plate to fit. Can you grind down the collet to make it flush.

Thanks Steve

Um, engine back plate?

Or the drive washer that sits behind the prop?

I suspect its the drive washer that you are referring to here and it is not sitting back far enough onto the collet? The best way is to turn down both the taper of the split collet and the engaging inner diameter of the drive washer without changing the angle on your tool post to achieve parallel surfaces.

I have seen it done that way on a lathe and it allows the collet to sit further into the drive washer giving greater surface contact and alignment, providing of course that the collet does not show through the front.

I assume the cause is a too shallow a cut into the drive washers back?

Cheers.

Before I went and whacked metal off of a motor like that, I'd find about 100 ways to ask myself "is this problem due to the design and workmanship of the engine, or is it me?"

Just sayin' -- even with cheap Chinese crap I've gone and "fixed" nonexistent problems, to my ultimate dismay.

I have also used a large plastic washer with the 3/8" hole to be a spacer behind the spinner backplate.  Don't use rubber or wood.

Dave

Sorry, it is the spinner back plate . I have never seen this before. The collet comes out past the thrust washer. It makes it hard to face the nose ring.

Brett do you then step the hole in the prop.

   No. It only sticks out about 1/16" above the face the thrust washer, so once you get the spinner backplate on, the prop can have a conventional 1/4" hole. The part that sticks out is a perfect fit for the Tru-Turn. Many spinners come with a 3/8 hole and sleeves to make it fit 5/16 or 1/4 shafts, in this case, you just don't need the sleeves.

    This may seem like a silly arrangement, but once you nose it into the blacktop and only have to replace the prop stud instead of the entire crankshaft, you will see the beauty.

    Brett

If the collet sticks "proud" of the prop driver and interferes with the spinner backplate, I'd slip it onto a dowel of some sort and sand a small amount off the small end of the collet on a belt or disc sander, until it isn't a problem. This would keep the end "pretty square", and won't cause runout of the propdriver or spinner. Deburr both inside and out, of course. You might put a dab of flower clay on the area when you trial fit the assembly to make sure there's a little clearance.    Steve

  It's not the collet, it's the end of the crankshaft. The RO-Jett has a stub crankshaft that is not threaded on the outside. It has a 1/4" stud that threads into the crankshaft. For whatever reason, the very end of the crankshaft sticks out proud of the thrust washer.

   Brett

Because it is the end of the crankshaft, not the collet!

Because it is the end of the crankshaft, not the collet!

Yeah, that's what Brett said. You didn't say that until just now.  Steve