# Powered Compound



## Cholmes (Nov 30, 2013)

Is there a way to drive the small screw on a lathe compound? I'm talking about the one that the tool holder mounts to. I need to make several parts that are tapered and to have a power drive in the small compound would be very helpful. It only has about 4" of travel, an variable speed and reverse would be great. Any ideas would be appreciated.


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## Chucketn (Nov 30, 2013)

If your lathe cross slide handles are held on with socket head cap screws as mine are, you can use a battery powered screw driver or drill with an allen bit in it that fits the screw head. That's what I do.

Chuck


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## Cholmes (Nov 30, 2013)

chucketn said:


> If your lathe cross slide handles are held on with socket head cap screws as mine are, you can use a battery powered screw driver or drill with an allen bit in it that fits the screw head. That's what I do.
> 
> Chuck



Thanks Chuck, I hadn't thought of that! I will try that until I find a more permanent set up.


Chuck Holmes


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## Rbeckett (Nov 30, 2013)

You could engineer a small stepper motor to turn at a variable speed and both directions and fab up a bracket and clutch to make it work quite nicely.  I keep thinking I would cut a fairly large gear for the feed screw and a fairly small gear for the motor and that would give me a mechanical advantage over friction and stiction so that I could power it in tandem with the apron being engaged also.  That would give me a taper capability that would be quite nice fi I can slow the motor enough to not overload the cutter.  A NEMA 23 motor would or should be powerfull enough to turn the feed screw through the gears with no problem at all too.  Just a thought from someone considering the same thing as yourself.

Bob


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## fretsman (Dec 1, 2013)

Rbeckett said:


> You could engineer a small stepper motor to turn at a variable speed and both directions and fab up a bracket and clutch to make it work quite nicely.  I keep thinking I would cut a fairly large gear for the feed screw and a fairly small gear for the motor and that would give me a mechanical advantage over friction and stiction so that I could power it in tandem with the apron being engaged also.  That would give me a taper capability that would be quite nice fi I can slow the motor enough to not overload the cutter.  A NEMA 23 motor would or should be powerfull enough to turn the feed screw through the gears with no problem at all too.  Just a thought from someone considering the same thing as yourself.
> 
> Bob



Hi, Bob,

May I ask exactly what would be needed to run a stand alone stepper?

Thanks,
Dave


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## george wilson (Dec 1, 2013)

I happen to have a NOS motor off of a Suburban cylindrical grinding attachment for grinding punches. These motors cost about $850.00!! They have a built in variable speed unit enclosed inside the rear of the motor housing.

I have been thinking of mounting it with some rare earth magnets above the compound of my 16" lathe. The compound is large enough to mount the motor on. I could put a small pulley on the motor,and just use a vacuum cleaner round belt to go around the dial of the compound,which I'd lock so it couldn't roll freely. The first thing I have done with some new lathes,was take out the spring inside the graduated ring. They never turn freely enough to allow delicate adjustments. I drill and tap a hole,and make a little knurled knob to lock the dial with. When loosened,the dial is perfectly free to be adjusted.

Old time lathes,even into the 20th. C.,used "overhead drives". Hardinge WWI era lathes had this. You had belts hanging down that could be used to power the compound. Toolpost grinders could also me powered this way,as well as early milling attachments,etc.. The main overhead shaft was powered from the lathe itself. Angle irons could be used to make one for a lathe. Be careful to not make it so a belt could get tangled in the work,though!! That might bend the angle irons and bring the whole shebang down against the lathe. Perhaps WEAK belts would be in order,so they'd easily break if caught.

Those early methods were not OSHA approved!! Back then,you were expected to have sense enough to not get caught in gears,belts,etc.. That didn't always work out.


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