# Wood lathe conversion to variable speed



## Letrman (Nov 29, 2020)

Hey everyone. This is the first discussion post that I’ve ever posted in my lifetime. I already messed up my New Member Introduction somehow, so I hope this goes better. I have an old Rockwell/Delta wood lathe and I’d like to do away with the motor and pulley system and replace it with a VS motor. Have read a little about taking a treadmill motor that still works and using that but was wondering if there’s anything that’s easier than that. Such as not having to buy and lug a big heavy piece of equipment into my basement(my back). Such as something so simple that even a woodworker could install it. I understand “take the two white wires and put a wire nut on them”. For some reason, most electronics talk goes over my head. So I’m looking for suggestions as to how to accomplish this or if it’s even worth trying.
Thanks for listening


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## JOAT (Apr 9, 2010)

I imagine it could be done, but why replace a working system, with variable speed? Old saying, if it ain't broke, don't fix it.


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## Letrman (Nov 29, 2020)

I wouldn't say it's exactly working, but it's what I got when I purchased it. A bunch of belts and pulleys in a box. The guy was just selling it. He knew nothing about it. I've made it work for the last couple years but it's not at all efficient for me. I never intended for this set-up to be permanent. I can't keep bending down to change pulleys and I have very little space for making a better pulley system. But I could use the space the pulleys and belts occupy to store more junk.


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## CharleyL (Feb 28, 2009)

You could replace the motor with one that can vary in speed. If you kept the stepped pulleys it would allow speed ranges.

A DC motor would need a DC power supply and for it to hold speed well, a sensor/tachometer would need to measure the shaft speed of the motor and feed this signal back to the special power supply to increase the motor current as the load increased, and reduce it as the load decreased. 

An AC induction motor varies it's speed when the frequency of the AC power going to it changes in frequency. There are single to 3 phase controllers that can now be used to provide 3 phase power to a 3 phase type induction motor, and these will allow you to change the speed of this kind of motor. Don't try to slow a single phase induction motor by reducing it's voltage. It will loose power as well as speed, and when slow enough, the centrifugal start switch will close and energize the motor start winding, which is not designed to be energized for more than a few seconds at a time, and this winding will burn up rather quickly. A three phase motor has no centrifugal switch or start winding, so does not have this problem at slower speeds, but can have the cooling problem due to reduced fan speed.

I caution that with either AC or DC motors, the motor fan is usually connected to the motor shaft, so slowing the speed of the motor significantly when under load will result in the motor overheating. Keeping the speed at 50% or above will usually prevent overheating. Having the step pulleys between the motor and load will allow you to run the lathe very slow and still be variable in speed within the slow pulley/belt position without slowing the motor to less than 50%. Large motors that need a wide speed range are built with an auxiliary fan that runs at a constant full speed that is mechanically attached to the larger motor and it drives a fan to provide full cooling of the larger motor at any operating speed or load. 

Charley (an EE in a former life)


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## tomp913 (Mar 7, 2014)

VS Conversion for Lathe Take a look at this. You would still have the belts, but variable speed within 3 speed ranges. You don't mention the lathe model, but the write-up says that it fits Delta Midi Lathe #DEL46-45 (and maybe others with a little work). Looking at this to add variable speed to my Excelsior - seems like a good deal for $170. Check YouTube, there are a couple of videos out there showing the procedure.


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## old55 (Aug 11, 2013)

Welcome to the forum.


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## marecat3 (Nov 30, 2010)

welcome to the forum


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## sreilly (May 22, 2018)

Welcome aboard Mark.


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## roxanne562001 (Feb 5, 2012)

Welcome to the forum. Surplus Center is a good source for DC motors and speed controllers. DC Motors | Electric Motors | www.surpluscenter.com


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## JOAT (Apr 9, 2010)

Amazing. In all the time I owned, and used, my wood lathe, I never once changed the speed. And it worked just fine. Made a whole slew of carving mallets, found out that was all I liked to make on it, so sold it.


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## Letrman (Nov 29, 2020)

CharleyL said:


> A DC motor would need a DC power supply and for it to hold speed well, a sensor/tachometer would need to measure the shaft speed of the motor and feed this signal back to the special power supply to increase the motor current as the load increased, and reduce it as the load decreased.


Charley, thanks for your feedback. I basically understand what you're saying and how it works and will keep your idea in mind. I'll have to do some more reading.


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## Letrman (Nov 29, 2020)

tomp913 said:


> VS Conversion for Lathe Take a look at this. You would still have the belts, but variable speed within 3 speed ranges. You don't mention the lathe model, but the write-up says that it fits Delta Midi Lathe #DEL46-45 (and maybe others with a little work). Looking at this to add variable speed to my Excelsior - seems like a good deal for $170. Check YouTube, there are a couple of videos out there showing the procedure.


Thanks Tom but this won't work on the lathe I have. I have a Rockwell/Delta model 46-111, maybe 1960's. Looks like a nice conversion unit though, that would fit an Excelsior lathe.


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## Letrman (Nov 29, 2020)

Thank everyone for all your Welcomes! This _is_ a nice site to visit....wouldn't want to leave here.
Mark


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## Letrman (Nov 29, 2020)

roxanne562001 said:


> Welcome to the forum. Surplus Center is a good source for DC motors and speed controllers. DC Motors | Electric Motors | www.surpluscenter.com


Roxanne I checked out this site and I think they would have what I need. If I only knew what that was.


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## Letrman (Nov 29, 2020)

JOAT said:


> I never once changed the speed. And it worked just fine.


That's pretty much what I've been doing. I turned new handles for all of my lathe chisels. It was such a pain to change speeds that I didn't. You just learn to adapt. But now I want to change speeds quickly so that I actually do and learn why you do. I wanna make some misteaks. And then not. I really like the lathe I have and I don't think it's beyond me to be able to do this modification.


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## jw2170 (Jan 24, 2008)

G'day, and welcome to the forum.
I hope your issue is sorted out?


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## Letrman (Nov 29, 2020)

jw2170 said:


> G'day, and welcome to the forum.
> I hope your issue is sorted out?


G'day to you as well and thanks for such a great site.
My lathe issue is slowly starting to sort itself out. Now it needs to explain it to me.


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## roxanne562001 (Feb 5, 2012)

You might find this on youtube helpful 






yoniyon said:


> Hey everyone,
> 
> 
> Thanks Alot!
> Yon.





Letrman said:


> Roxanne I checked out this site and I think they would have what I need. If I only knew what that was.


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## gdonham1 (Oct 31, 2011)

Well you are opening a can of worms. I have a nova 16 inch you have to change pilly to change speed. I also have a jet 12 vs lathe. In 20 years the parts for the jet will be impossible to get. 40 year lathes with pillows will still be running. Figure out how to install motor and pillows, get running and sell it and get a vs speed lathe. Old lathes are good sellers. If you get it running you might like it. Changing speed is simple but you will find you don't need to change speed often.


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## gdonham1 (Oct 31, 2011)

gdonham1 said:


> Well you are opening a can of worms. I have a nova 16 inch you have to change pilly to change speed. I also have a jet 12 vs lathe. In 20 years the parts for the jet will be impossible to get. 40 year lathes with pillows will still be running. Figure out how to install motor and pillows, get running and sell it and get a vs speed lathe. Old lathes are good sellers. If you get it running you might like it. Changing speed is simple but you will find you don't need to change speed often.
> [/QQUO


Pullies not pillows. Autocorrect darn


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## mgmine (Jan 16, 2012)

An old lathe like this isn't really worth the effort or expense of trying to convert. Most people don't need anything langer than a mini or midi lathe. If you do need a longer bed then you can get a Harbor Freight VS one for about $300 with a coupon.


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## kp91 (Sep 10, 2004)

If you want to play with treadmill motors, here's the king of those conversions.

Home (jeremyfielding.com)


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## Coleve (Oct 31, 2012)

Letrman said:


> Hey everyone. This is the first discussion post that I’ve ever posted in my lifetime. I already messed up my New Member Introduction somehow, so I hope this goes better. I have an old Rockwell/Delta wood lathe and I’d like to do away with the motor and pulley system and replace it with a VS motor. Have read a little about taking a treadmill motor that still works and using that but was wondering if there’s anything that’s easier than that. Such as not having to buy and lug a big heavy piece of equipment into my basement(my back). Such as something so simple that even a woodworker could install it. I understand “take the two white wires and put a wire nut on them”. For some reason, most electronics talk goes over my head. So I’m looking for suggestions as to how to accomplish this or if it’s even worth trying.
> Thanks for listening
> Hi this is how I carried out my wood lathe and grinder to variable speed. It’s not just a matter of reducing the speed, because this also reduces the torque. I installed a frequency inverter and a separate speed controller. the inverter is expensive but I found it the best method. Hope this helps.


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## mark greenbaum (Sep 26, 2010)

Letrman said:


> Hey everyone. This is the first discussion post that I’ve ever posted in my lifetime. I already messed up my New Member Introduction somehow, so I hope this goes better. I have an old Rockwell/Delta wood lathe and I’d like to do away with the motor and pulley system and replace it with a VS motor. Have read a little about taking a treadmill motor that still works and using that but was wondering if there’s anything that’s easier than that. Such as not having to buy and lug a big heavy piece of equipment into my basement(my back). Such as something so simple that even a woodworker could install it. I understand “take the two white wires and put a wire nut on them”. For some reason, most electronics talk goes over my head. So I’m looking for suggestions as to how to accomplish this or if it’s even worth trying.
> Thanks for listening











Shopsmith Digital Motor Conversions | Facebook


This is a group for people who want to upgrade their Shopsmith tools with a digitally controlled motor.




www.facebook.com





Find a free electronic treadmill, and join this group. People are using the motors and electronics for converting Shopsmiths (I will do it soon), and I am sure you can figure out a way to convert your lathe too.


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## Rusty Nesmith (Feb 1, 2020)

An inverter duty motor and frequency drive would be easy enough.


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## Roland Johnson (Oct 27, 2015)

I have a Delta lathe from the early 50''s set up with 4 step pulleys using the weight of the motor also from the 50's to control the belt tension which works fine and gives multiple speed options by occasionally of setting the belt a notch. bought an ac inline speed controller and never used it. 
The pully system falls in with the Kiss line of thinking and is fine with me!


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