# Heavy 10L Motor Upgrade



## MrWhoopee (Oct 29, 2018)

After the timing belt upgrade to my Heavy 10L, I discovered that it was quite possible to stall the 1 hp motor. This naturally suggested another upgrade.
I found this 2 hp motor on CL, paid $40.




It is physically larger than the 1 hp, but initial examination tells me it will fit (with modifications of course). 
The shaft is 1" dia., the original is 7/8", which means boring and broaching in order to use the original pulley. The motor came with a triple sheave which is about 1/2" smaller than the larger original drive pulley. The seller gave me a 4-step pulley with correct bore and keyway. I it trimmed down to a 2-step, the large step is 1/2" larger than the original (4" vs 3.5"). I'm inclined to use this one. I would like to get a little more speed and I don't think this would be too much for the spindle bearings.

Trying to get all my ducks in a row BEFORE I pull the 1 hp out. I won't have use of the lathe until the I get the new motor in.
Looking for opinions, experiences and suggestions.

Thanks


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## markba633csi (Oct 29, 2018)

A 2 horsepower squirrel!  
Should work fine if you can make it fit
M


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## pontiac428 (Oct 29, 2018)

Are you equipped to run a 3-ph. motor?  I'd assume so, but thought I'd ask...

I bet that will run great, maybe even help you find what the next weak link is.  I mean that lightly...  Murphy lives in my garage, and likes to make his showing at times like this.


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## MrWhoopee (Oct 29, 2018)

pontiac428 said:


> Are you equipped to run a 3-ph. motor?  I'd assume so, but thought I'd ask...
> 
> I bet that will run great, maybe even help you find what the next weak link is.  I mean that lightly...  Murphy lives in my garage, and likes to make his showing at times like this.



Yes, I have a 7.5 hp RPC. I understand the "next weak link" and was already trying to predict it. 

Just discovered I have wiring transfer problems (which I should have anticipated).


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## Norseman C.B. (Oct 29, 2018)

2hp. ?    That's one TOUGH squirrel !!!............................


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## markba633csi (Oct 30, 2018)

When the going gets tough, the squirrels get tougher!  lol


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## Cooter Brown (Oct 31, 2018)

You don't want to put anything bigger than a 1hp motor on a Heavy 10L......

http://vintagemachinery.org/pubs/1617/17770.pdf


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## MrWhoopee (Oct 31, 2018)

Cooter Brown said:


> You don't want to put anything bigger than a 1hp motor on a Heavy 10L......



That document suggests that South Bend considered 3/4 hp to be a minimum (required). The fact that it was not produced with a motor larger than 1hp may have been dictated by costs or the limitations of the the flat belt drive. I'd be interested in any mechanical limitations that might dictate a 1 hp maximum. Surely someone has done this before.


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## pontiac428 (Oct 31, 2018)

The size of the motor is one way of defining a maximum.  The size of the load is another way.  In other words, if your work never applies more than 1 hp worth of load, then what does motor size matter?  Startup torque won't cause your lathe to twist itself up like a stick of licorice on a 2 hp motor.


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## Cooter Brown (Oct 31, 2018)

I cant find anything that states the maximum motor size for any of south bend's lathes.... Only Atlas tells you the maximum motor HP for the 7b shaper.... I hope you dont wear out your spindle bearings prematurely with that 2HP motor...


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## MrWhoopee (Oct 31, 2018)

I'm not so concerned about the spindle bearings. Plain bearings can handle heavy loads, excessive speed would be the killer for them. Components such as gears and shear pins in the drive and feed trains might be another matter.

This may all be moot, the wiring compatibility issues may bring this to a halt unless I want to replace the drum switch and wiring.


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## Cooter Brown (Oct 31, 2018)

Do you have the newer style Heavy 10L with the bronze spindle bearings or the older style with the cast iron spindle bearings?


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## MrWhoopee (Oct 31, 2018)

Cooter Brown said:


> Do you have the newer style Heavy 10L with the bronze spindle bearings or the older style with the cast iron spindle bearings?



1963, bronze bearings


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## Cooter Brown (Oct 31, 2018)

Nice I wouldn't try it with the cast iron spindle bearings......


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## dlane (Oct 31, 2018)

I wouldn’t hesitate putting one on my 10L just be careful not to crash it, maybe Leave the belt a little looser.


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## old_dave (Oct 31, 2018)

Cooter Brown said:


> You don't want to put anything bigger than a 1hp motor on a Heavy 10L......
> 
> http://vintagemachinery.org/pubs/1617/17770.pdf
> View attachment 278761



I don't see a date code on this; it does show postal zone rather than zip code and the lathe has small dials on the compound and crossfeed. My 1966 SB catalogue shows them offering a choice of 1 H.P. motors in various voltages (or a two speed 1/2-1 H.P.) for the Heavy 10. A mid 1990's South Bend leaflet on the Heavy 10 also shows a choice of single or three phase 1 H.P. motors (or the two speed 1/2-1 H.P. motor).

David


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## Cooter Brown (Oct 31, 2018)

old_dave said:


> I don't see a date code on this; it does show postal zone rather than zip code and the lathe has small dials on the compound and crossfeed. My 1966 SB catalogue shows them offering a choice of 1 H.P. motors in various voltages (or a two speed 1/2-1 H.P.) for the Heavy 10. A mid 1990's South Bend leaflet on the Heavy 10 also shows a choice of single or three phase 1 H.P. motors (or the two speed 1/2-1 H.P. motor).
> 
> David


 it says 1951 copyright at the very bottom.....


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## old_dave (Oct 31, 2018)

Thank you, I see that now. I wonder what led South Bend to up the recommended horsepower. 

David


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## dlane (Oct 31, 2018)

There stout enough, and horse power isn’t what it used to be


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