# Electric Motor Frame Designation ??



## JR49 (May 6, 2017)

Just wondering if the motor frame designations have changed in the past 50 years ?  More specifically, the frame # on the original 3 phase motor in my 1969 vintage Logan lathe is "E66".  I've read where a lot of guys use motors with 56 frame #'s for their lathes. Are these motors interchangeable?  I'm asking because I have a chance to get an almost new  56 frame motor at a really low price.  So, what say you experts??  Thanks,  JR49


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## Dave Paine (May 6, 2017)

The frame code/ID defines things like type of mount, e.g., foot vs face, mounting hole spacing and most important the shaft OD and keyway dimensions.

I do not know how many motor standards exist.  Frame 56 is a NEMA frame standard.  Many sites on the internet have charts stating various aspects of a frame size.

An example at Baldor for NEMA.

http://www.baldor.com/Shared/pdf/nema_chart_04.pdf
Another example from WEG.

http://ecatalog.weg.net/files/wegnet/WEG-weg-technical-poster-ustechposter-brochure-english.pdf

I am not familiar with an E66 frame code/ID.


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## Old junk (May 6, 2017)

Not interchangeable frame designation includes mounting points,shaft diameter and height ect.66 frame is old probably pre 1955.56 seems to be most widely used as replacement cause of cheaper cost but would have to modify mounts,pullers etc.hope this helps.baldor still makes 66 frame motors by the way.


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## Ulma Doctor (May 6, 2017)

the 56 frame is loosely considered a universal motor for many applications.
in my paying job, it is my goto frame when retrofitting old equipment with new motors


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## 4GSR (May 6, 2017)

Just about every machine tool I've had to replace a motor on in my past, I've had to make adjustments on the motor mount to accept the new motor.  The latest one is my 15" Sheldon lathe.  I don't recall the frame size it was, the newer one is a 184T frame.  Didn't even come close.  The old set of holes were on a larger spacing and the new frame size, there was not enough room for new holes.   So I cut a couple pieces of flat bar that would span the old mount and provide room for new tapped holes for the new motor mount.  

For conversion from a 66 frame to 56 frame, I'm sure you will have to do the same or something similar. As for the shaft size, it maybe the same and it may not.  Something tells me the shaft size may be the same, just the base dimensions are different.  May get lucky and the shaft height may be the same too.  Without more information, I couldn't tell you.  

BTW- you won't find a new motor with a 66 frame size today.  I suggest, making the adjustments for the 56 frame size motor so that way if someone after you gets the lathe and needs to change out the motor, they will thank you.

Ken


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## CluelessNewB (May 6, 2017)

I can tell you that Logan currently only sells 56 frame motors.   I believe the  frame size on the 3 phase motor is on m y Logan 820 was "P16" but it's a bit hard to read.  It's a Peerless 1/2 hp 1750 RPM 220-440V 2.4-1.2 Amp 3 phase 60 Hertz.


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## Wireaddict (May 9, 2017)

I agree with what everyone said here but I have one more comment.  To make sure you get the best match to your old motor measure all of its dimensions (shaft diam, height  & length, mounting hole pattern dims, etc.) then compare with online or other motor frame data chart.  BTW, another place you can find motor frame data is in the _Machinery's Handbook._


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## Linghunt (Aug 29, 2017)

26TH EDITION  2000, I post a copy.  2638 pages to dig thru

http://www.linghunt.com/101Spearfishing/Spearfishing101RefManuals.html#MACHHANDBOOK


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