RF-30 motor pulley on 7/8" shaft?

[bulgie]

Hi, nothing new here folks, just another RF-30 sufferer upgrading the motor to 3-phase. OK, it's an Enco clone, not Rong Fu brand, is this still the right sub-forum?

The motor I got is a fairly awesome "Extreme Duty" Baldor, $50 locally, used but in good shape. I'm pleased except for how heavy it is. Does even the fan shroud have to be thick cast iron? Jeez. Seems like a great motor otherwise and it looks like the dimensions will match up well enough, except for the shaft diameter.

Anyway my question is, has anyone put the motor v-belt pulley (sheave?) on a 7/8" shaft? I don't even know what the original motor shaft diameter is, can't measure without taking it off and I'm not ready to be without a mill yet. I assume it's smaller though.

I have a lathe, so I can bore the pulley to .875", assuming there's enough "meat" there in the pulley, around the bore.

I'd also be OK with buying a new multi-step pulley, if that's something I'm likely to find. I don't need the four diameters to match exactly, a bit bigger or smaller would be OK even if it means getting a different belt length. The speed range on the VFD I'm using will more than cover any discrepancy in sizes, between the original and replacement pulleys. I actually like the idea of leaving the existing pulley on the original motor, so I can swap it back in if this new motor lets its smoke out. Even another RF-30 (or similar) pulley, that would need to be bored out, would be awesome. Anyone parting out a dead mill-drill?

Grateful for any advice from people who've made this kind of swap.

Thanks
Mark B in Seattle

 

[matthewsx]

You should be able to use a single sheave pulley since you have the VFD for speed changes. Just do a little math so you know what size to source.

John

 

[bulgie]

You should be able to use a single sheave pulley since you have the VFD for speed changes. Just do a little math so you know what size to source.

John

Thanks, yeah I thought of that, and I did that on my drill press, but I was hoping to use the VFD to increase the range from my slowest to fastest speeds. Lower low, higher high, I want it all! But your way is sensible and I may end up doing that.

 

[markba633csi]

You probably don't need a 4 step pulley- a 2 step would give a good range I think
Have you run the new motor on your VFD yet? Probably a good idea to run it beforehand
Used motors can have issues- find them early

 

[bulgie]

You probably don't need a 4 step pulley- a 2 step would give a good range I think
Have you run the new motor on your VFD yet? Probably a good idea to run it beforehand
Used motors can have issues- find them early

Hmm, 2-step would increase my chances of finding one, will investigate.

Yes I hooked it up to the drive immediately on getting home. It runs as smooth as... something really smooth. (Simile impaired)
I also googled and found this is a recent model, still for sale, typically $1200 to $2k plus shipping. Other than the excess weight I'll have to crank up and down, I can't believe my good luck. (Knocking on wood)

Bearings are smooth, shaft not bent. I can't put it under load yet but it spins up to 2x the rated rpm no problem.

Thanks!

 

[Makintrax73]

The shaft on my 2hp Enco clone (Buffalo) appears to be 7/8" unless there is some weird metric size in between 3/4" and 1" I'm not aware of.

Not sure if the motor style has changed but Grizzly is a good source of parts since they have exploded diagrams and easy online ordering. Might be worth a look if you want to stick with a step for jobs you need extra torque multiplication or high speed, etc.

 

[Shotgun]

A 7/8" shaft will be overkill if anything.

 

[bulgie]

The shaft on my 2hp Enco clone (Buffalo) appears to be 7/8" unless there is some weird metric size in between 3/4" and 1" I'm not aware of.

Not sure if the motor style has changed but Grizzly is a good source of parts since they have exploded diagrams and easy online ordering. Might be worth a look if you want to stick with a step for jobs you need extra torque multiplication or high speed, etc.

22 mm is somewhat common I hear. Not saying that's what the Enco motor has, but it could be.

If so, good news. 7/8" is 22.2, so an easy bore job, won't even have to re-cut the keyway, just shorten the key by 0.2 mm (~ .008")

Thanks for the reminder to check Griz, will do. Say, you don't happen to know what they called their RF-30 clone by any chance? It will make searching easier if I know that.

 

[RJSakowski]

7/8" appears to be correct for my RF30 clone, c.a. 1984. The OEM motor is 2 hp.

 

[bulgie]

7/8" appears to be correct for my RF30 clone, c.a. 1984. The OEM motor is 2 hp.

Thanks, great news.

Re: buying a Grizzly pulley: Looks like G1006 is the model name. They say the motor pulley is in stock, yay.
$90 though, hmm, just to save me from having to take the one off my existing motor? Maybe I'll re-think this. Chances of putting the old motor back on are slim. Especially if the existing bore is already 7/8", then I can switch the pulley back and forth, it's reversible & low risk.

Anyone have a coupon or promo code for Grizz, maybe that would sway me toward buying.

Oh also, how hard is it to get off? If the pulley is blank on top, nowhere for the gear puller to push, how do you get it off? Is heat all I need?

So many questions! Thanks.