3 to Single Phase Motor Changeout

I've gotta Rockwell abrasive belt finishing machine (6x48 belt sander model 31-520) and I want to change a 3 phase motor out to a single phase. The original Rockwell (Baldor) motor that I pulled out does not have any info on the frame number. Anyone have one of these or knows what frame number I need? I know I can take it to a local motor shop but I'd like to shop it on the web to know what to expect to pay before I do that.
KC
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There are catalogs on the OWWM site.
http://owwm.com/MfgIndex/Publications.asp?ID 41
Later catalogs list the recommended motors and specs on later pages.
Light a man a fire and he will be warm all day. Light a man afire and he will be warm the rest of his life.
UA100
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I took a look on OWWN and they do list Rockwell/Delta part numbers, but no specs including frame number. I should have stated that I am looking for a replacement that is not necessarliy a Rockwell motor as I have seen they tend to be pretty expensive. That is why I'm looking for the general specs on the motor, which I've found all but frame info.
KC

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Kevin Conway wrote:

The link below is to a NEMA Quick Reference Guide for the various frame dimensions. It should help.
http://www.marathonelectric.com/motors/manuals/SB371/back.pdf
-- Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)
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Kevin Conway wrote:

That's understood but later Delta and Rockwell machines used the same NEMA standards as others.

What is the serial number of the machine?
UA100
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The serial number is DW3385.
KC

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Kevin Conway wrote:

Hmmm? 1968. A very good year for Delta machinery.
Let's look at the ancient text.
Ouch!
Looks like you have a semi-proprietary mounting pattern. The Delta catalog calls the motors out as being either a No. 6 or a No. 8 1/2 (Delta mounting patterns).
You have a couple of choices. Drill the cabinet (not too big a deal really) or make a pad to go between the motor and the cabinet base (an inbetweener) with some T-nuts facing one way to match the hole pattern in the new motor (any 1 horse 3450 rpm will do) and T-nuts going the opposite way to match the holes in the cabinet.
Sorry. Wishing it was easier. On the other hand, you do have one of the finest 6" X 48" belt finishers money could/can buy.
By the way, you Kevin Conway the actor?
UA100
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An inbetweener sounds the easiest at this point. The present motor is 1725RPM, I would imagine that is key to keep from buring the wood, not 3750RPM?
Sadly, no; no acting skills here.
KC

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Kevin Conway wrote:

The OEM motor is reputed to be 3750. Probably you have a different set of pulleys.

Too bad. The money comes in handy from time to time.
UA100
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The OEM motor I took out, which I still have says its 1725RPM...I assume it OEM, its a Rockwell (Baldor) motor, 3ph/220V.
KC

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By the way, how does the ancient text decipher the serial number DW3385 1968?
KC

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Kevin Conway wrote:

Delta started 1968 with serial number DS-9453. They started 1969 with serial number EG-100. DW3385 falls in between those numbers.
UA100
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Kevin,
I sent you an e-mail yesterday saying that I would check out my motor size. I didn't actually look at the frame number, It was in a difficult position to read. However, it appears to be the same size as my original band saw motor, which I believe to be a 66Y frame type. They are both double ended, with cover nipple on opposite end. It makes it easy to reverse the rotation. On three phase motors, swapping any two leads will acheive the same thing.
They are slightly larger than todays norm. It didn't cause any problem when swapping my band saw motor. I just boosted it up slightly higher to make up for the difference. As I have not pulled the pulley, I don't know the shaft size. My band saw was 3/4" and now is 5/8". They make bushings to adapt the larger pulley to the smaller shaft. I don't think it works quite as well in the opposite direction.
Anyway, my motors are Rockwell/Marathon, not Baldor. My point is that you probably don't need to be overly concerned with getting the exact size as long as you don't go bigger than your stand can handle. There is plenty of room to play with when you are using belt driven machinery. (To the best of my knowledge)
I hope that this helps.
Eric Tuck
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