Small polyflex belts

The Gates guide give four reasons for premature failure:

1. Under designed drive
2. Belt rolled or pried onto sheave
3. Object falling onto drive
4. Severe shock load

If the belt is 20mm short, it's possible that the second applies?

The replacement belt was a genuine gates so at least I knew it wasn't a cheep copy. Cant be sure of the original on the lathe though.

I am concerned on how tight the belt is to change speeds with the tension leaver in the slack position I cant see any way to reduce the tension the idler gives to the belt.

I have been told the belt size has changed but that's ok. I am doubtful the layout of the position of the idler and pulleys have changed but who knows.

On my lathe it uses B section belts, I use Powertwist belts, these are link type belts with no metal parts, one end of the link has a slot, and the other end a barb. One of the belts is genuine Fenner, and the other is a Chinese copy, the copy needed about an hours running under load to break it in but after that all OK. The size goes down to a top width of 5/16".

Ian S C

Hi Mark,

Reading the posts again I think your problem is probably down to the new belts simply being too small. Don't discount the possibility of a mistake in the Manual or what you've been told by the supplier!

The possibility that you've been misinformed is supported by posts from Jason and John. They both confirm that there's a version of your lathe that uses the larger 5M730 belt.

If I were you I'd try a 5M730 belt.

Dave

Edited By SillyOldDuffer on 12/09/2017 11:45:21

Hi Dave

I think the 5M730 belt is the one to try it will be a lot less strain to change on my fingers and more importantly the belt !

The bearings will probably have less of a hard life as well.