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LeBlond servo shift power

Ekeller2

Plastic
Joined
Sep 5, 2021
Hi, I just purchased a 3 phase(5 hp) Leblond servo shift lathe. I only have single phase so how should I convert it? I see three options, replace the motor with a single phase, VFD or a rotary phase converter. The servo shift has me hung up on what to do. 1/2 of the shift (gears next to chuck) has been converted to manual. I’m not sure if the other side works or not. I understand the servo shift to be very expensive to repair. And that’s kind of why I was interested in a vfd to convert it. Thanks
 
Hi, I just purchased a 3 phase(5 hp) Leblond servo shift lathe. I only have single phase so how should I convert it? I see three options, replace the motor with a single phase, VFD or a rotary phase converter. The servo shift has me hung up on what to do. 1/2 of the shift (gears next to chuck) has been converted to manual. I’m not sure if the other side works or not. I understand the servo shift to be very expensive to repair. And that’s kind of why I was interested in a vfd to convert it. Thanks

Fix the servo shift and use a R P C to run it. The servo shift is a simple system and is very reliable. In about 15 years of daily use the only thing that has happened to mine is a wire to the brake magnet broke. it cost nothing to fix. It sounds like yours is a bit cobbled up. first thing to do is un do whatever the ignorant has done. It is not black magic no mater what all the experts who have never owned or worked on one say.
 
I bought a leblond servo shift that did not work...

Biggest issue was dirt, it was awful. The lathe must have lived in a shop that used oil on lathes or screw machines.

After that i found the shifting pressure was low - need 300 PSI. The relief valve is cheap - just a hole in an oil line fitting. Bought a new fitting and drill a smaller hole.

Now she works like new.


Just my experience. The design is really solid, not much serious can go wrong with it.


karl
 
OTOH, if you decide to go VFD. You need a small one to run the oil pump and a large one to run the spindle.

i could see where it would be real easy to drill a hole in the side of the head stock and add a lever to enable moving a row of gears by hand to give low and high ranges of speed.

From there, you'll need to gut the electrical and start over. All the servo shift electric will just conflict with the VFD
 
Thanks for the info, I will get a rfc ordered. Any advice on where to start with the servo shift troubleshooting? I would like to make it work again if I could. Thanks
 
Clean it up good. inside and out.

look for stupid broken wires, anything else you can see.

change head stock oil, replace filter.

check outlet oil pressure when its trying to shift. (rocking back and forth)

I have manuals, too big for here. send me your email if it can take larger files.
 
[email protected]. Thanks

On the phase converter, are you guys running a step up transformer as well? I have single phase 240 volts and the lathe is 440 volts 3 phase. Phase converter I’m looking at is only going to change phases not voltages. Thanks
 
I'd really suggest you set it up for 220 3 phase. Bit of motor rewire and then a transformer rewire and you are good to go.
 
Leblond at one point has a manual shift kit conversion or the servo. I've not seen other than referece to it's existance in older RK leblond literature. Personally I'd try to go back to the servo is you have all the parts,

That said the only trouble I ever had with one was wrong oil and a fail on the "rocking motor" assembly. Typical hydraulic servo. keep it clean and run the proper oil.
 
I have a LeBlond Servo Shift and I strongly recommend the rotary phase converter over the VFD. Be aware that the Servo will not shift if the incoming power leads are reversed. Simply reverse two of the incoming lines and test again.
After you have the unit powered, troubleshooting the Servo Shift will be easier. I spent some time learning how the Servo Shift works while repairing mine so check back here when you are ready to troubleshoot the Servo.
 
I am currently trying to get the servo shift working on my 24" regal. Currently the spindle will run, brake works, clutch works, lathe will shift if i select gear and manually close contacts for pump with brake engaged. Cant seem to find a zero speed switch on this one.
 
Clean it up good. inside and out.

look for stupid broken wires, anything else you can see.

change head stock oil, replace filter.

check outlet oil pressure when its trying to shift. (rocking back and forth)

I have manuals, too big for here. send me your email if it can take larger files.
Would you mind emailing me the manuals for Servo shift also? Please and thank you!
[email protected]
 








 
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