PM 728 Mill- Issues and upgrades.

It's funny man, we both have the "same" avatar, we both have PM-72x's, we gotta have the same hand guns/rifles/knives....hay...what's your wife's name?.....:D
 
Great minds think alike!
R
 
Next plan:
Hand cranking the Z axis is a workout. I want to automate it. Rather than go with a geared DC motor, I would rather get part of the way to CNC and put a stepper or servo on the Z axis. Then I can build a primitive board to step it.
I have no idea how to attach the motor to the Z. I have no idea what size or type of motor. I have no idea how to build the control circuit. I definitely know that I will figure all this out with the expertise available here!
I would invite any comments or suggestions at this time as I plan this. I will also review the many threads here to see what others have done. This was discussed in a PM727 thread but I am not sure the Z axis looks the same.
Robert
 
Yeah, I posted similar questions. Always a bit surprised that there a X axis power drives but not Z except for bridgeports etc. Perhaps it's the weight, but my Z isn't that much harder to turn than X. A stepper would be nice as you could set simple increments. You thinking direct gear drive or belt?
 
I was thinking direct. Not sure how much torque that would take? The side handle is geared down about 4:1. When these machines are converted to ball screw they are typically direct drive and the ball screw has a greater pitch. Shooter I believe used a NEMA 34 on a PM 272 with ball screw?
Robert
 
Maybe for holding power that NEMA 34 would be a good choice. So, a spline to whatever size shaft is on the 34...7mm? Then a bracket to mount motor to column. I think a potentiometer would be cool to control it, but you're thinking moving towards a single axis CNC?
 
I have already got a lead from Jim Dawson on something like this:

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Yes I am headed toward Z axis automation with a plan to totally convert in the future.

Robert
 
I played with the idea, I think our gear drive versus belt drive for spindle was a bit of a roadblock. There is a guy on YT that did get past that. I'll see if I can find him.
 
I was going to take off the side handle and try to mount direct to the Z lead screw. I believe it is a keyed shaft. I could use a double ended stepper for so I could move the head (at least a little) if the system failed. I suppose you could mount the motor on the side and drive the horizontal shaft.
Robert
 
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