# electric lead screw



## Kernbigo (Dec 22, 2017)

Here is a picture of my electric lead screw on my south bend 9" wide bed. I have a total invested in it of $27, works good. Power supply off a lap top ,$5, $8 for the controller on ebay, and $14 for the dc motor and gear reducer. Running 19 volts to the motor, with about a 4-1 timing belt gear ratio.​


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## Dabbler (Dec 22, 2017)

Do you have ambitions to synchronize it with the spindle and make it suitable for cutting *any *threads?

... Very nice work BTW!!


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## Tim9 (Dec 22, 2017)

Are you using a PWM so you can vary the speed of the motor ?


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## Kernbigo (Dec 22, 2017)

No desire to cut threads, i can put the 1 gear that is disengaged back up to mesh and cut threads, also disconnect the dc motor drive belt. I'am using a pwm so i can very the speed and also it is reversible. I also have a treadmill motor on the headstock spindle, so i can very that speed also. A hole $27 dollar investment.


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## Dabbler (Dec 22, 2017)

Here's an idea:  set it up so during power feed, using a dpdt microswitch, you can set up an autoreverse or a stop when you are at a shoulder.  Saves having to disengage at the last second!

I find your project very exiting!


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## derf (Dec 23, 2017)

I'm in the process of building the same thing, can you give some more specifics about the motor and controller? Possibly links to a source?
 What is the rpm range?


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## benmychree (Dec 23, 2017)

I wonder what the purpose of this installation is???????


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## gzoerner (Dec 23, 2017)

This project eliminates the noise and wear of the gear train.

I'm working on a similar project.  My approach is somewhat different in that I'm using a stepper motor and a microprocessor (Arduino) controller.  The software is basically complete.  Now I just need to make a housing for the electronics and power supply.

My system measures the spindle RPM so the carriage motion will be calibrated in thousandths/turn.  The carriage travel speed will be continuously variable from .0005"/turn to .012"/turn.  It also has an optical limit switch which stops the carriage very quickly, then reverses for 1/2 turn to relieve the pressure on the engagement lever.


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## derf (Dec 23, 2017)

It not only eliminates the noise and wear on the gear train, it makes it very simple to change and fine tune a feed rate for older lathes that do not have a quick change gearbox. The gear train is only necessary to cut threads, keeping the spindle in sync with the lead screw. For general turning, it is a pain to have to manually change gears over to set a specific feed rate. By driving the screw electrically, one can control the speed from a pot.
 It is as simple as disconnecting the gear train by moving the banjo out of the drive line, moving the feed direction lever to neutral and then using the electric motor to turn the screw.


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## Kernbigo (Dec 23, 2017)

as the last member just wrote i could not said it better, i think i'am going to make 1 change in order to get a little more speed on the top end for roughing cuts. I'am going to run a 3-1 gear ratio instead of 4-1.


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## Kernbigo (Dec 23, 2017)

https://www.ebay.com/itm/Japan-TSUK...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2650

https://www.ebay.com/itm/Mean-Well-...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649
I also used a power supply off a laptop 19 volts to power the pwm, total out lay $27, i had the timing belt and pulleys, also had the cable tv old box.


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