Mini Mill Tune Up And Power Feed

[bmac2]

Christmas and New years have past so I’m back to tuning/cleaning up my mini mill. I saw in the Princess Auto flyer (the Canadian version of Harbor Freight) they had white lithium grease on sale. Any time I go to Princess Auto I take a wander through the surplus section. Most times it’s like going to the dollar store but I have found some good stuff, brand name tools, heat shrink, zip ties and once Mitsubishi NEMA17 and NEMA24 stepper motors.
I’d seen these worm shaft motors in surplus for a while but with no nut, an unknown voltage and the absence of any other spec I wasn’t interested. But I’d been thinking of adding a power feed on the X axis so I looked up the part number on the internet and low and behold.

P/N: 5503740 D
Power Seat Tilt Motor for a Chevrolet Malibu
RPM: 190 RPM @ 12 Volt DC
1.5A No Load /17A Stall @ 12V.

I figured if it had got enough power to lift my 210lb butt in a car it should work as a power feed and the 190 RPM seems about right so I dropped the $9 Canadian and took one home. Messing around on the bench I couldn’t stall it with my hand at 5V so it’s got some torque and at 12V no way was I going to stop it.

So this is my rough plan. The frame will be 1/4” aluminum where I need rigidity and 3D printed where it just needs to keep the chips out. A few years ago when I first got into casting I was lucky enough to be gifted a lot of aluminum scrap from a local fabrication shop and a lot of it was 1/4” plate so I think I’ll mock up the frame just to get a better feel of how things are going to fit.

The motors are sold as right hand and that would put the motor above the bed. I don’t think I have ever had anything on this little mill sticking out to where this could become an issue but I don’t like the idea. It turns out that you can just undo the 4 screws and swap it around making it left hand and that will put the motor down below the bed.

 

[timo_gross]

Haha, probably would have bought one. On a Mill with 4 mm screw pitch this would go about 760 mm/min. Probably good enough, if you can slow down properly. Worst case it does not work as you hoped.

On my mini Mill the motors stick out to the side. You need to check if anything is in the way when you drive the y-axis full stroke.
Is your mill on a stand? Is vertical down any option? If possible, I would also try to keep everything below table top, just in case you will have a part that is longer than your table. The day you decide to mount something, you will need to drill a hole in the end of a table leg .
I would even try to move the clutch handle to the front, not up.

The next thing I wonder would that be suitable for a quill feed? Or can it raise and lower the head of the mill?

Success and keep posting how it is going.

Greetings Timo

 

[terry123]

Will definitely be following this one! I have pondered something similar but was unsure about how to power a DC motor.