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Adapt metric pulley to 5/8" shaft?

I'm going to replace the AC motor on my Lathemaster 8x14 lathe with a DC treadmill motor as I want varible speed. (I checked & can't find a

3-phase motor that small, otherwise I'd use a VFD).

Anyway, the original 1 HP motor has a 16mm keyway shaft (0.630") and the new DC motor has a 5/8" (0.625") keyway shaft.

How do I deal with the 0.005" difference? Is 0.005" within the normal tolerance range for pulley ID's and I can forget it? Or should I machine, split, and press fit a very thin bushing into the original pulley set? I want to use the original pulley set as it includes a timing gear.

Regards, Ed Ferguson

Reply to
Ed
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If you have some shim stock (feeler gage), it should be adequate for your HP and load requirements. Use Loctite between the shim and pulley, if you'd prefer to. I did this recently for a nearly identical application. The .005 runout would be problematic, in my opinion.

WB ................

Reply to
Wild Bill

I'd take the time to re-bore it and install a bushing (assuming there is enough meat in the casting.) It's more work to begin with but it'll probably make you happier in the long run.

Koz

Ed wrote:

Reply to
Koz

If you have a clamp type knurler then knurl the shaft on the new motor till it grows to the proper size. lg no neat sig line

Reply to
larry g

Oh man. I know I have seen your work before, Larry.

Reply to
Jon Grimm

Get some slivers of 0.0025 shim or wire to use as centreing wedges (or carefully carved matchsticks). and use Loctite 638.

The only problem is that you will need to heat the pulley if you want to get it off again.

Will you have to make a custom size key, or do the pulley and shaft have the same key widths?

HTH Mark Rand RTFM

Reply to
Mark Rand

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