Interesting. A safety conscious model engineer who actually encloses the belt.

There seems to be a lot of weight (the motor) at a distance from the tool mount. Will it hold firm under vibration?

One of my first tool builds was of very similar design – I didn't even consider covering the belt drive, however! The spindle was a home-brewed ER25 affair running in cheap ball races. The toothed belt is tensioned by the ball race jockey wheel mounted in a slot for adjustment and the driving pulley and idler (bottom left in the picture) are interchangeable to give high and low speed ranges. It's (under) powered by a sewing machine motor but it revs to 10,000 rpm – it says on the box!  Vibration is a bit of a problem and I wouldn't trust it to do any accurate grinding but if fitted with a proper spindle it might pass muster. Still, like I said, it was one of my first projects. I've learnt a lot in the five years since then.

John

Edited (twice) for sloppy typing.

Edited By John Hinkley on 16/10/2019 20:06:15

Edited By John Hinkley on 16/10/2019 20:08:31

Since this is a low powered tool (motor power is the limiting factor) I was going to suggest using flat pulleys and using the back of the existing belt as a flat belt. Possibly though the teeth on the outer face might still impart some vibration effects that would effect grinding.

However rather than reverse a toothed belt, better would be a reversed polyvee because the full power transmission capabilities of the multi 'V's not really be required for this tool.

Ian P