New motor for old 12" Atlas/Craftsman lathe - HP? Source?

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Kimball McGinley
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New motor for old 12" Atlas/Craftsman lathe - HP? Source?

Post by Kimball McGinley »

I have decided to buy a new motor for the 1955 12" Atlas lathe that I bought recently. The motor wiring is all compromised, the plug had no ground, etc. Is 3/4 HP appropriate? That is what is has now. 115 VAC House power only. Is Open Drip Proof OK, or TEFC? McMaster-Carr wants a fortune ($350), any suggestions?

Same questions for the (reversing) switch ?

Didn't find this in FAQ.

No rush, thanks!
John Evans
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by John Evans »

1/2-3/4 is normal. Go visit HF about $140 for same. Be sure you get a 1725 motor.I've used several of thier motors with no issues,get a 20% coupon and go for it.
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redneckalbertan
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by redneckalbertan »

If you are changing motors, consider a 3 phase motor and a VFD.
spro
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by spro »

I think you want a motor with a 1/2" dia shaft to fit the small step pulley. Craigslist is a source of good used motors too. There is a good motor called Craftsman Power Tool Motor, 1/2 or 3/4 hp. It is capacitor start and double shaft ball bearing motor. These are older motors and very reliable. They have a reset button and are not too heavy. If you are turning and putting a load on the motor, you don't want it bogging down to where the start field is trying to engage. Since it is double shaft, it can be mounted either way and I don't see reason for reverse on the Atlas. You have control of traverse direction of the lead screw so can do left hand threads etc without reversing the motor.
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Harold_V
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by Harold_V »

spro wrote:I don't see reason for reverse on the Atlas. You have control of traverse direction of the lead screw so can do left hand threads etc without reversing the motor.
A lot depends on what you expect from the lathe in question. Personally, I wouldn't own a lathe that wouldn't run in reverse, but that's me, and may not reflect the feelings of others.

By having a reverse, you can extract taps and dies from extensive penetrations----as well as polish in reverse, which often is desirable, especially when a surface is interrupted. Many more reasons to have a reverse, especially once you've enjoyed the convenience.

One big issue is overcoming a threaded spindle. That can be a deal breaker.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
spro
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by spro »

There are a lot of Craftsman motors on ebay right now. Some have the obvious capacitor case and the heavier have it in the base. They Are electrically reversible and some are inexpensive. As JE said, make sure it is 1725 rpm not 3450. They look identical in either model.
spro
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by spro »

HV. Right of course. I'm trying to remember when I had a chuck back off a threaded spindle. It wasn't the Atlas 12 1/4" because it didn't have reverse.
earlgo
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by earlgo »

The Atlas Lathe Catalog (1958) that I have says that either the 1/2 HP SP (Cat No 2720), the 3/4 HP SP (Cat No 2790), the 1/2 HP 3P (Cat 2710) or the 3/4 HP 3P (Cat 2712) is appropriate. It also lists the 1 HP drum type reversing switch (Cat 6685).
The Atlas I use has a GE drum type reversing switch but the Dayton 2x440 from Grainger will work, too.

I occasionally thread small threads with the spindle reversed and the tool on the back side of the work and have not had a chuck come loose yet. But, the operative words are 'small threads' 16 TPI or greater. Do not try this with a 2-4TPI. (I do it this way so I don't have to stop the feed on a dime. Of course one has to start on a ha'penny, but for me that is easier.)

--earlgo
Before you do anything, you must do something else first. - Washington's principle.
spro
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by spro »

Thanks very much by me and others. We need to not bad mouth the Atlas. It is a tight package when assembled correctly. The "one I had", had an ON/OFF switch in the lower headstock. I never needed reverse and therefor didn't know the uses it could handle.
There was another reason and it becomes touchy. With a threaded 1 1/2" x8 spindle, The tendency is to lock the back gears and knock the chuck up tight for reverse. Over time, there were posts about how to lock the chuck without assuming it has cast iron gears, because they aren't. There were threads and info which some apparently understood. These gears don't suffer impact well. They are quiet and mate well. Right out of the box they have to mate well over time (what I saw). In one shop I have a piece of material on the floor. it is 1/2 of an Atlas bull gear and the index pin. I replaced that gear and the lathe went on to someone else and was stolen.
Because it was a 12" swing lathe and could be stolen easily.
spro
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by spro »

Leave with two impressions. Of course. That is why I must say more. The Atlas 12 1/4 has Timken roller bearings. When that is tightened up and level to a solid bench, it is good solid lathe. It was one of the last I know which had an indexed bull gear. There were attachments to utilize these things. Many great things were done with these lathes and they fold in time. Time is the future for many and having a lathe of that capacity is still alluring. Very good depending upon the skill of the operator.
Kimball McGinley
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Re: New motor for old 12" Atlas/Craftsman lathe - HP? Sourc

Post by Kimball McGinley »

Thanks to all!
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