Z Axis Power Feed for Precision Matthews PM-728VT Mill

@fursphere
Thanks for the posts. I really haven't gotten that far into it yet. Racking and stacking priorities. I would purchase the Priest Z axis power feed but I want a beefier motor and I don't think a beefier motor is on the horizon. I've seen several Blondihacks tube videos and I'm glad she did this one. I had thought about using an Align power table feed but I couldn't see how I could configure a way to connect it. The parts you list and the video is a great idea for future consideration.
 
I have a PM 940V. I made an adapter that replaces the hand crank. The adapter has a hex on the end. I use a drill and socket to drive the Z drive shaft. The position of the Z axis handle of the 940 is different from your 728. I do also have a Grizzly G0619. The Z axis handle was quite a pain to use. I fixed that by using an electric drill. I posted that solution on hobby-machinist. Maybe this will give you an idea for at least a stop gap approach: https://www.hobby-machinist.com/thr...z-axis-of-a-grizzly-g-0619.84157/#post-744037
 
The Align power feeds sold by PM are very good quality, the Z is $330.00 and 45 minutes assembly time including bolt-on, drill a hole and done!
 
@RodSME
The electric drill is a good idea. Never thought about it.

@Cletus
The Align power feeds sold by PM is what I was actually looking at. However, I didn't think it would fit on my PM-728VT. I don't want to spend the money just to find I can't get it to fit or work for that matter. Have you installed one with this version of mill? If you have, I would be interested in seeing a couple of photos if you would be willing to share.
 
No experience with the PM-727VT at all. Give PM tech support a call and have a chat with them on that application, they will surely know.
 
@Cletus
I actually gave PM a call about using an Align power feed after I initially posted my question and at least in their estimation, there is no way to use an Align power feed for the Z axis on my mill. If there is, I would like to know how.
 
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I have been toying with this. I like the idea of using a stepper motor a lot. If you ever go to CNC you have one axis done already. I have been considering alternative ways to attach a motor to the end of the Z lead screw. I decided on a coupler (lovejoy or some other) with the hub threaded to M12. I would then machine a slot in the hub and put a clamping screw on the side to lock it like a shaft clamp. I think that is better than the wave washer design and will not damage the threads. Heck, you could do that and a wave washer.
Like this:
1633994763073.png

Robert

Like this actually:
1634004097157.png

One end could be threaded m12.
R
 
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Ahhh, then, I stand corrected. A stepper motor may be a very logical and viable solution.
 
rwm said:
I have been toying with this. I like the idea of using a stepper motor a lot. If you ever go to CNC you have one axis done already.
Click to expand...

I think this is partially true. CNC conversations usually swap out the acme screw for a high quality ball screw (reduce / eliminate backlash). This may not even be needed on the Z axis, but all the kits come with a Z ball screw.

For a simple up / down power lift, the acme screw should be fine. And you'll have the stepper for a CNC conversion later, if desired. :)
 
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fursphere said:
I think this is partially true. CNC conversations usually swap out the acme screw for a high quality ball screw (reduce / eliminate backlash). This may not even be needed on the Z axis, but all the kits come with a Z ball screw.

For a simple up / down power lift, the acme screw should be fine. And you'll have the stepper for a CNC conversion later, if desired. :)
Click to expand...
This is a great point. You could still use the stepper but you would be making a new adaptor to connect to the new ball screw shaft.
Robert
 
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