Lathe spindle motor problem

J

jcmullis2

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I have a 8.7x31 lathe with the factory 850watt brushless dc motor. It doesn’t have much torque and I want to get a different motor if it’ll fix that. The problem is I wanna keep it 110v.
I can go larger to 1.5kw motor like it has for about $350 but I don’t know if it’s torque will be enough.
The other thing my son suggested is a Nema 34 closed loop stepper motor with 12nm of torque. That will cost about $200. I don’t know if it’ll be enough to keep the motor spinning under the normal turning and parting operations either.
Lastly is the closed loop servo. I don’t know if it’s even available in 110v or if it will be able to handle the normal loads.
I can take lighter passes and adapt but I’m hoping to get a little more umph out of my lathe. If anyone has any experience with this please help me out. Thanks and Happy New Year!
 
Don't go stepper motor. The working torque is less than you think, and they have a curve where torque goes way down as RPMs go up (generally speaking).

I am surprised an 8.7X31 lathe only had an 850 watt motor. That is barely more than some of the higher tier 7X16 lathes.
 
There has to be something wrong with the motor or the control unit. A 850 watt ,motor is about over 1 hp. The 1.5 kw motor should be fine if you decide to go that route, but I would check out the original first. I have a 8" lathe and it came with a 3/4 AC motor. . I also have a mill that uses a 500watt brushless dc motor. Both have plenty of torque.
 
Yeah they use that Chinese math on the thing. This lathe is basically a 8x16 with a extended bed. They even call it a wm210v-L extended and it has a 1.5 inch spindle bore diameter.
The control board is probably the culprit from what I’ve heard others say. I don’t wanna buy a control board and it not improve things. There’s a 1100watt motor that’ll bolt right up so I might try it. I just wanna be able to part steel without any problems. Maybe someone will reply that’s changed out their motor for something stronger.
 
JC: It sounds like the controller is mis-adjusted. There is usually a torque compensation adjustment on the circuit board. It may not be labelled as such however. Has this machine always been like this or did the problem just start recently?
You might try checking Youtube for info on how to set it properly
Also check out this repair service for motor controllers:
-M
www.olduhfguy.com (Pete)
 
markba633csi said:
JC: It sounds like the controller is mis-adjusted. There is usually a torque compensation adjustment on the circuit board. It may not be labelled as such however. Has this machine always been like this or did the problem just start recently?
You might try checking Youtube for info on how to set it properly
Also check out this repair service for motor controllers:
-M
www.olduhfguy.com (Pete)
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It’s always been like this. I heard there’s pots to adjust the speed and torque but some of these lathes had different motors so I really don’t know if it does or not. I really don’t know anything about this stuff anyway and don’t wanna kill it. My son is coming over tomorrow and he knows enough to do it so I’m gonna have him try to dial it in if it has those adjustments. That would be too easy of a solution for my luck. Maybe my year will start off right. I’ll let you fellas know.
 
markba633csi said:
Just have him mark the adjustments with tape or a sharpie so you can go back and then try them one at a time. I bet you will be able to improve it
-Mark
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I was sweating it too much evidently. I called him up and was bugging him somewhat and he sent me some links to videos about trim pots and how they’re adjusted. He says it’s really basic dc motor stuff. I get off the phone and watch the videos and the videos broke it down in simple terms. I’m sure these adjustments will help. The motor is like the rest of the lathe. They slapped it together and didn’t spend any time tweaking or fine tuning things. I guess that’s somewhat understandable considering they bounce around the globe in a crate. However It would have been nice if they had included a decent manual. One that covered all the adjustments so the lathe could perform at its best if the owner set it up properly. If I can get this issue resolved I’ll have a darn good little lathe. I’ll know more in a few hours and I’m hoping for the best. Wish me luck guys. Happy New Year to everyone
 
It's possible the factory that puts these together doesn't even know how to adjust it or even try. They probably get the circuit boards from another division and just assemble and give a quick turn-on. If that. So yeah, quality control minimal, cost minimal, let the end user do the final tweeks
-Mark
ps can you imagine a US manufacturer doing that in the 50s, 60s or 70s? No way, their business would suffer greatly
 
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