Reduction gearing for mill head drive?

[daved20319b]

Found it... the Z axis uses a NEMA 34 Stepper (with the help of the pneumatic cylinder).

From the Syil manual:
"The Z Axis uses the NEMA 34 stepper. They have a holding torque of 460 ounces per inch. And consumes 3 amps per phase."

I'm also going to use a NEMA 34, but it sounds like mine is considerably larger than yours, about 1200 oz. in. and draws 6 amps per phase. I really wanted to direct drive mine, but I'd have had to fit a new longer lead screw to mount the motor at the top of the column. I'm really curious how yours is directly driven but they were still able to fit the motor inside the column. This is what I'm planning for mine:



Not my mill, this is s photo I snagged off another forum, but it's almost the only Z axis power feed I've found for this mill that wasn't driving the existing handwheel. I intend to do a much better job of pulley alignment and belt and pulley sizing, although I think this pic was taken while it was still a work in progress, and the undersized belt was just for testing. It should still fit inside the rear cover, although I'm sure I'll need to do some cutting. I'd really like to fit the driver in there, too, but I think there's just too much stuff in the way. Not a big deal, my power supply, driver, and controller for my table feed are in an enclosure on the wall next to the mill, and that works fine (mostly gratuitous showing off pic):



I still have some loose ends to tie up, but it's fully functional as is, and it sure is nice not having to crank that handwheel anymore, especially when I'm running a fly cutter. Anyway, thanks for the info, later.

Dave

 

[DAT510]

My mill was already converted when I purchased it used..... I did take it apart to clean it and replace the spindle bearings (over 0.010" runout). From what I remember, stepper hung below the ball screw. My guess, is because the ACME screw was replaced with the Ball screw, they were able to choose the screw length that allowed them to direct drive the screw from below.

Here's the parts diagram.

 

[daved20319b]

My mill was already converted when I purchased it used..... I did take it apart to clean it and replace the spindle bearings (over 0.010" runout). From what I remember, stepper hung below the ball screw. My guess, is because the ACME screw was replaced with the Ball screw, they were able to choose the screw length that allowed them to direct drive the screw from below.

Here's the parts diagram.

Yeah, that's a MUCH shorter motor than the one I got for mine, I'd have to cut a hole in the stand to do something like that. Hmm, not actually a terrible idea though, it wouldn't encroach on the space in my stand that much, and it sure would be nice to be able to dispense with gears and belts. And if I did do that, I could fit all the electronics in there, too. Definitely something else to consider, thanks! Later.

Dave