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

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
.................

"Ed" wrote in message
om...
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

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:

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

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

"Ed" wrote in message
om...
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

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

"larry g" wrote in message
...
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

"Ed" wrote in message
om...
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

On 13 Apr 2004 10:33:57 -0700, (Ed) wrote:

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

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