Lathe motor upgrade, is this overkill?

[57buick]

So I have a 1954 model Rockwell 11" lathe that I have mostly restored. Nice setup with quick change and all that, I scrapped all the old crappy wiring and installed a VFD on the stock motor. The orignal cabinet is racked bad and I am going to be building a custom new frame bench for it.

I just happened to pick up two 7.5hp motors brand new never been wired for $75!!! score I know its overkill but Im thinking I can finally get rid of the crap Reeves drive which the bearings are squeaking in it anyway and replace motor with one of these 7.5hp ones I got for almost nothing.

Question...using the higher horsepower motor (same RPM rating as original motor) wont that just give me better torque when Im running it half speed like 30hz as long as the motor is getting sufficient cooling of course?

 

[matthewsx]

Yes, overkill. Maybe you can program the VFD but probably better to find a 2hp.

John

 

[57buick]

What would be the disadvantage?

 

[57buick]

The VFD is already programmed and running great, I have an adjustable knob to vary speed and the RPM of the new motor is the same

 

[ttabbal]

I imagine that the added torque could be more likely to damage something if bad things happen. It could also put more stress on the bearings etc.. It also means more expensive VFDs etc., but it sounds like you already have that handled.

A bit like putting a 3x bigger engine in a car without improving everything else.

Great deal on the motors.

 

[57buick]

My VFD is rated for 10hp just because it wasnt much difference in price and figured the extra rating would be good overhead for years to come especially if using the braking function which has to handle spiking

 

[57buick]

Here are some pics of my lathe, I got it for $500 and was working but really grimy so I disassembled everything and cleaned and repainted. The guy said it got dropped on the end moving it which is why the cabinet is racked so bad. So Im gonna be building a new frame for it out of 3x3 1/4 wall. That will be the perfect time to scrap the reeves drive in cabinet and upgrade the motor and just use my VFD

 

[Jim F]

Stubby like sucker, isn't it?

 

[57buick]

its a 11x24" model there was an extended 36" version but I think this is all I could ever need as a hobbyist lol

 

[57buick]

Im in the process of building the new control box for the variable speed and direction, ill post pics of that next week