Cromwell S800 lathe – NECO motor

[smfParticipant @smf]

[smfParticipant @smf]

I wonder if someone could help me with a lathe motor question. I have a Cromwell S800 which was fitted with a Ward Leonard motor control. The ac motor and dc generator and all of the original wiring are missing, but I have what I think is the original DC motor. If possible, I'd like to reinstate this in the lathe. The motor plate is attached. There are 5 wires going into the motor, whereas I would have expected only 4 – 2 for the armature and 2 for the field winding. Could someone suggest an appropriate controller and what the 5 wires might be please? Or is this not worth the time and effort? I currently have a 1/2hp 3 phase motor installed with a VFD, which is a little bit underpowered and doesn't provide the speed range of the original system.

Thanks

Stephen

[John HaineParticipant @johnhaine32865]

Frankly I think you'd be better off fitting a new bigger 3ph motor and vfd. If you got a 2 pole motor and ran it up to 60Hz you would have an even wider speed range.

[Ady1Participant @ady1]

If you're using the lathe a lot then I would say get a VFD with more grunt

[Dave WoottonParticipant @davewootton]

Hi Stephen

I did up a S800 some years ago ( its the light green one on the lathes website that now looks like it's in someones front room!) I fitted a 1hp motor and VFD , from memory it was a 4 pole motor that I ran up to 3000rpm and it worked fine. I did look into DC drives for the original motor but the expense was not much different to a VFD and motor, and bearing in mind the original motor must be well over 60 years old didn't think it worth it. Seem to remember the field voltage was not in the standard range for an easily obtainable DC drive, but it was about twenty years ago now so might have that wrong.

Cromwell are very good lathes but I couldn't ever get used to the controls in a different position, must not be very adaptable I suppose, good luck with it.

Dave

[smfParticipant @smf]

Thanks all. I think I'll change to a 1hp 3 phase motor, and likely go to direct drive (which was how the original motor was set up). I can always reinstall the countershaft that someone has put in if needed.

Dave – your restored lathe looked very smart, but I know what you mean about the controls! I've restored the base on mine but need to tackle the lathe itself next.

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