Compound slide auto feed

[Christophe Mineau]

Hi again,

Still for the same project, I had to machine small cones with the compound slide.
I decided it was time to make this little gizmo I had in head to stop manually cranking endlessly this small double pin wheel my compound has.

I made this little tool out of scrap pieces, it's a little like a T allen wrench, the transverse bar is made out of square stock, with two holes that fit the two pins of the wheel. The shaft is made of an old Ikea like allen key, that unexpectedly found a real use here.

And the motorization is made with a very cheap 4V Lithium screw driver I found for less than 20€.

I would say this changes life !

[rossbotics]

Sure beats cranking the compound by hand, I have a small lathe like yours, so the next time I have to turn tapers I'll remember this little trick

Doug

[mklotz]

Good idea, Cristophe.

The same idea could easily be adapted to provide a power carriage traverse for a Unimat lathe. The handwheel normally used for this has only one handle but it would be simple to drill and Loctite in two pins for the device to engage.

Power screwdrivers provide an inexpensive source of high-torque, low-speed rotation in a compact package. There are all manner of tedious rotation jobs in the shop on which they can be used. As an example, I adapted mine to power the jaws of the lathe chucks out and in when cleaning the chucks.

[DIYer]

Thanks Christophe Mineau! We've added your Compound Slide Auto Feed to our Lathe Accessories category,
as well as to your builder page: Christophe Mineau's Homemade Tools. Your receipt:

Compound Slide Auto Feed by Christophe Mineau

tags: lathe, power feed

[Paul Jones]

Marv,

I like your suggestion for the Unimat. I bought a slow speed motor, variable speed power supply and cog wheel and drive belt for my old Unimat to convert to a longitudinal power feed but never did this. Using the method demonstrated by Christophe would be simpler and easier to install. I am also consider installing a clear machining shield on three sides of the Unimat but didn't know how to access the longitudinal feed and limit the machining shield opening. This should work.

Thanks,

Paul

[mklotz]

Marv,

I like your suggestion for the Unimat. I bought a slow speed motor, variable speed power supply and cog wheel and drive belt for my old Unimat to convert to a longitudinal power feed but never did this. Using the method demonstrated by Christophe would be simpler and easier to install. I am also consider installing a clear machining shield on three sides of the Unimat but didn't know how to access the longitudinal feed and limit the machining shield opening. This should work.

Thanks,

Paul

I'm picturing something like the following...

Two pin setup as per Chrisophe on the Unimat longitudinal feed. Shaft passes through a close-fitting hole in the chip shield. Outside of chip shield shaft has a knurled hand wheel that allows for manual operation of the feed. End of shaft has a machined 1/4" hex which fits the chuck on a power screwdriver for motorized feed operation.

Years ago, before power screwdrivers, I built a reversible DC motor rig to power the longitudinal feed. The interface to the Unimat hand wheel was a rubber friction roller pressed against the knurling on the hand wheel. It worked but lets just say it wasn't one of my finer design efforts. If I were to redo it today I would definitely use a power screwdriver.

[hemmjo]

I bet you also get a much better result as this eliminates 2 sources of surface finish imperfection. A more constant feed rate improves the result. Turning by hand introduces up/down and side to side forces on the slide that can deflect the tool path.

The hand wheel on my slide is held in place by a hex nut. I used a socket in my variable speed drill to do a similar thing, but I could not use it to back up as it loosened the nut.