View Full Version : Power the Z on my Grizzly X3

06-03-2010, 07:24 PM
I’ve been thinking about adding a motorized drive to the “Z” action of my Grizzly X-3 Milling machine. Has any one done that? I’ve counted the turns it takes to move the head up or down, say 6 “and it’s 120 or 20 turns per inch. And there is no reason why I shouldn’t power it. I have an X-Y table drive that I bought from LMS after I gave up building one. I had a couple hundred-dollar credit so I used it.
I have a motor that is capable of reversing and is geared down to about the right speed. The shaft turns 88 rpm. It’s from a hospital bed. The motor is rated 1 to 5 duty cycle. I don' think that should bother.
Another thing about the motor is the drive shaft coming out of the gear box and be switched to come out the end.
I have a nice heavy-duty switch to select UP OFF DOWN. And I plan to use a heavy-duty push button to activate the action. I have some limit switches but with the push to move button I shouldn’t need them.
I have a multi-groove belt, and have made pulleys to go on motor and backside of the hand wheel that drives the Z action.

The set up will have to be mounted on a angle because the Z drive comes out of the mill base on an angle.
I will make some sort of box to cover the drive unit and contain the controls.

One cool thing about this setup is I can still turn the handwheel by hand with out much more effort than with out the motor.
I guess what I would like from you gentlemen is any suggestions you may have the will aid me in this adventure.

dr pepper
06-03-2010, 07:40 PM
I'm thinking of doing this with my recent trident mill.
The motor you have resembles ones found in kids electric trikes/cars.
The motor I have is a parvalux, which means its a worm/wheel, so I'd not be able to turn the o/p shaft, so I'm gonna need a freewheel of somesort.
I dont think you need much advice on that, you've pretty much got it sorted, the only thing I'd say is make the motor cover a good fit to keep the chips out, the other thing is the pulley on the motor is a long way out, you might need a bearing block on the end if theres any appreciable force on the shaft, or move the motor assy nearer, but it doesnt look like its done yet.

06-03-2010, 09:55 PM
After posting the photos, I went back to the shop and turned the output shaft around to come out the other end. This allowed me to make a larger pulley for the motor and gain a little more speed.
Using the larger pulley also shortened up the distance between the motor and hand wheel allowing me to reposition the motor. By removing the top drawer in the bench I will place the motor there under the counter top. This will protect the whole system from chips and clear up the counter top.

06-03-2010, 10:36 PM

I did something similar with the knee on my Rockwell mill. The motor and gear reduction were liberated from a 1970's Rockwell circular saw to maintain the pedigree ;) With the hand crank working off the primary reduction, there is alot less resistance than there would be directly on the knee leadscrew. I replaced the handle with a conventional handwheel since this pic, as I forgot to remove it several times and found it could remove itself just fine under power :) I scrounged the controller out of an old treadmill--the whole thing really works just great.


Bob Ford
06-04-2010, 12:49 AM

If the push button is the type that you have to hold down to make it run I think you would be OK. A momentary switch normally off might save you or the mill from harm.


06-04-2010, 02:12 AM
Yes Bob, the button that I found is spring loaded and has to be held in for contact.
I don't think that I will have to purchase any thing for this project. I found it all in my stash.:)

06-04-2010, 11:08 AM
Guys, aren't you afraid that parts of your body (not necessarily your hands :)) can be pinched by the open belt or sticking out handle?

dr pepper
06-04-2010, 11:47 AM
That belt doesnt look new, and suspiciously looks like an alternator drive belt.
Are you thinking of a speed control, or just on off.
That motor is only rated at 1/10th HP, but for a 75 watt motor it looks meaty, if it'll lift dead bodies then it'll lift a mill table you'd think.

06-04-2010, 01:39 PM
dr pepper, the belt is not new, I salvaged it from a treadmill. The motor produces pleaty of touque as it is geared down from 1750 rpm to 88 rpm. I plan to make a belt guard as soon as I decide where the motor will be. After reversing the output shaft I think it will be located in the area now occupied by the top draw (see bottom photo).
Don't think I will need any speed control. Only plan to use it to make long moves of the mill head.
Thanks for your thoughts:)

06-09-2010, 03:22 PM
Done and it works great:)
9 " per min. travel time.


J. R. Williams
06-09-2010, 03:50 PM
I added a power drive to my mill using a gear head motor and run the unit with a dedicated VFD . I had a drive on the knee of my old mill to use when boring as the head drive did not function correctly. The mill had a sprocket on the knee drive shaft. The attached site has the details.



Bob Ford
06-09-2010, 08:48 PM
Except for no swarf guard it looks good to me. Nice problem solving.