What's new
What's new

Vintage lathe hydraulic drive

Got a Logan

Nov 27, 2022
Good morning. Does anyone out there have any information about this hydraulic drive on my 11 inch Logan lathe? The rectangular box above the headstock has a tag saying SWANN MFG. CO. Lathe drive 3.jpgLathe drive 2.jpg It appears to be an ancient B 17 "Flying Fortress" machine gun turret rotator powered by a General Electric electric motor Model Number 5KC48UG708ET. I'm seeking this information because even one of my sons who is an electrical engineer is not finding any information on how to convert the motor from its present 120 volt configuration to 240 volts.

Thanks in advance for any help.

Ray W


  • Lathe drive 2.jpg
    Lathe drive 2.jpg
    929.4 KB · Views: 15
That's pretty neat! Probably not very practical, but neat!

To state the obvious, it's stupidly easy to get 120V from 240V single or 3 phase in a multitude of ways.
Bill, the motor is an AC motor that presently runs on 120 volt household current. There are no instructions on the motor itself on how to wire it for 240 volts. My son found lot of wires in a metal flexible conduit running from the motor to the on-off switch. Some of them are connected to the switch and some are connected to nothing. So we're looking for any information that would include a wiring diagram for this motor. Both of my sons are professional engineers, one electrical and the other mechanical, with good computer skills but they can't find anything by searching the motor Model Number. Maybe that's because it's a very old motor since it's connected to a WW II vintage hydraulic pump. That's why I'm hoping to find someone who actually may have some personal knowledge of this setup.

Garwood, the motor is presently wired to run on 120 volts and works OK. The goal here is to rewire it to run on 240 volts.

I would have much preferred a lathe with a conventional electric motor and V-belt drive. But after losing my home and home shop in a wildfire and finding this lathe locally I went for it. At age 78 I don't have forever to get a shop back together.
My guess is the terminated wires in the conduit going to the switch are leftover from when it was pulley drive with a single or 3ph motor and was wired for forward/reverse rotation. Since its been converted to hydraulic drive, there is no need to run motor in reverse, you would reverse flow of fluid instead.

Another guess would be that is a one of a kind conversion, looks well done.
What's that going to do for him? His motor is wired for 120V, He wants to run it on 240. He's GOT the 240, just needs to make the motor
What's that going to do for him? His motor is wired for 120V, He wants to run it on 240. He's GOT the 240, just needs to make the motor compatible.
Boost trans can run in reverse…..220 in 120 out.

Cheers Ross
The problem with being an electrical engineer is you might well have no background in motors. Much like being a doctor who works on feet might have no background in brain surgery.

That said, if an EE who knew his basics had any one of the million books on motor windings, he could pretty easily figure it out.

And, of course, none of that will do him any good if the motor leads necessary to re-connect the winding are not brought out to the terminal box. If they're not, all you could do is go into the winding and add leads...which is probably beyond the scope of practicality.
Due to the chain drive, weldment construction, surplus airplane parts, and tag made on a Roovers Tapewriter, I'm betting that the "Swann Manufacturing Company" consisted of one person named Swann making one-off doodads for themselves in their home shop.

Need to see the wires coming out of the motor to determine if it can be reconnected for 220 volts.
Thanks to all of you who have responded. Since the motor has a model number on it I'm hoping somebody will have some information on that motor or know how to get it. Information on the motor says it will run on 230 or 115 volts so this should be doable. I'm a geologist and it didn't take me long after finishing college in 1969 to forget most of what I'd learned except in the specialty I've been in for over 50 years, engineering geology. So I can't criticize my son for not being a motor expert anymore since he's been out of college for about 15 years. His specialty is robotics, although during his employment with Lockheed Martin Space Systems he did invent an antenna for military and aerospace applications that Lockheed patented.

Hopefully some motor or computer research genius will have a wiring diagram for my motor. My son told me all the wires are color coded and have numbers or letters on them so a wiring diagram will enable us to "get 'er done".

Ray W
I have found older motor model numbers to be of little use when it comes to figuring out their wiring.

It isn't clear whether you have removed the cover on the motor where the wires enter. That's where you will be reconnecting it for 220 volts, and where there is usually a wiring connection diagram. A photo of that area would be a lot more helpful than the model number.
1) OP does not want to use a 230/115 transformer operating in step-down mode. ( Quick, clean, nearly foolproof, and elegant in its own way. )
2) Motor plate shows it is designed for operation on either 115 or 230, so the proposed re-wiring *IS* do-able.

Here's where it gets interesting:

3) IF Post #17 means that the wires inside the electrical cover *ON THE MOTOR* are marked, then all you need is a practical electrician's book covering standard motors and an ohmmeter. ( I'm referring to the wires coming out of the interior of the motor. )

There are books, Audel's for example, for electricians and other tradespeople who are not engineers, but need simple, practical information about how to wire various standard motors.

The key is that are standard ways of lettering/numbering motor leads ! The ohmmeter will let you confirm which standard applies to this motor.

As an aside: Early in my career, an old-timer told me "All an engineering degree really is, is a life-long license to learn!" [ Might be improper grammar, but his meaning was clear and proved true IMHE. ]

John Ruth
BSEE Clarkson 1977
Since 'information' (?) on the motor says it can run on 230v, you are essentially home free.

I don't know how to do it, but it is a simple matter to use a Fluke meter (or other non-Chinese made multimeter) to determine which leads need to be connected to each other and which leads are connected to the line. I don't know how to do it because I've never needed to do it....but I am aware that it's very common for motors to lose their lead labels and no one gets too worried about it. I bet if you spent 10 minutes online looking up 'how to identify motor leads' you'd find the answer.