# electric lead screw



## Kernbigo (Nov 25, 2017)

I made a electric lead screw drive for my 9" wide bed south bend lathe. The problem i ran into the motor ran out of torque at a real low speed, it was a 50 rpm and i need a 30 rpm. Has anyone have a good cheap source for gear reduction dc motors ?


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## T Bredehoft (Nov 25, 2017)

Try an automotive window drive motor, 12 volt.  I have one on my Mill, it peaks out at 8 inches a minute, direct drive, 10 pitch screw, 80 rpm.  I can slow it down to about 1 IPM, or 10 RPM. I bought 4 of them from a local junk yard, for $20.00 total.


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## Kernbigo (Nov 25, 2017)

Kernbigo said:


> I made a electric lead screw drive for my 9" wide bed south bend lathe. The problem i ran into the motor ran out of torque at a real low speed, it was a 50 rpm and i need a 30 rpm. Has anyone have a good cheap source for gear reduction dc motors ?


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## JimDawson (Nov 25, 2017)

Automotive windshield wiper motor?


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## RJSakowski (Nov 25, 2017)

Old drill/driver motors will work.  About ten years ago, our local DIY was selling 18 volt drill/drivers for less than $15. The batteries were crap but the motors are quite strong and you get a variable speed control in the bargain.  You can get one at HF for under $16.

Using pulse width modulation rather than a rheostat or variable voltage control will improve low end torque.


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## Dave Paine (Nov 25, 2017)

If the automotive suggestions do not work, try an internet search for "DC gear motor".   These units are common to drive augers.


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## Kernbigo (Nov 25, 2017)

that is what i used rpm to fast 55 rpm need about 30, i ran a pwm , ran out of torque at low speed taking a .03 cut on the lathe ( check out the picture)


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## f350ca (Nov 25, 2017)

The Hardinge HLV use a dc motor to drive the carriage. Its set up so that the fields get full voltage all the time and the voltage to the armature is varied, using just a variable transformer. Never seams to be lacking in power.

Greg


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## T Bredehoft (Nov 25, 2017)

JimDawson said:


> Automotive windshield wiper motor?



Yup, Jim, Ford Windstar wiper motor moving the head on my PM25 up and down. I use the hand feed on the quill for Z movement.


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