[Tryan15]

I am new to the forum and suffering from information overload. I am planning on doing a CNC conversion of my Homier X2 Mini-Mill. But, I don't want to lose manual operation of the mill. X and Y seem easy enough with cranks on the output shaft of the dual end steppers, but Z is a problem. It seems that at the very least it should be upgraded to an ACME screw, but that appears to rule out retaining the three-spoke handle for manual drill operations. What is the best solution for upgrading the Z-axis without losing manual operation?

[Pxsi]

I have the green “Grizzly” version of your mill, and was contemplating the same then, then I got a Harbor Freight drill press and didn’t worry about it.

Pxsi

[S_J_H]

If you use a ballscrew you can still use the factory rack and pinion drive with the 3 spoke handle on the Z axis.
So you only need to mount it in a location that won't interfere with the factory mechanism.
I used the Fignoggle plans for my x2 which does just that.
Steve

[Bubba]

Back when I was going to convert my RF31, I read a lot about losing the handles (expecially when using ball screws) and I took the advice.

I have now adjusted very easily to doing all my "manual" machining via MDF in the cnc and don't even miss the handles. For instance today, I needed to drill a hole in a shaft to be threaded. Put the shaft in a V block, ran the quill over to the center of the shaft using the jog feature and drilled the hole. Done quickly and easily with the keyboard and don't miss the hand wheels one bit.

If I were to do it again, would do exactly the same thing.

[Tryan15]

If you use a ballscrew you can still use the factory rack and pinion drive with the 3 spoke handle on the Z axis.

Sorry for the newbness of the question, but how does this work? Does the ball nut disengage?

I have now adjusted very easily to doing all my "manual" machining via MDF in the cnc and don't even miss the handles.

That's encouraging. I will have to give this some consideration.

[philbur]

Forget the handwheels, believe me you won't need them. Also seriously consider cncing the z-axis column not the quill. Then lock the quill and forget about it.

Even if you only ever use you cnc machine manually just think what you've got. A machine with three axis DRO and power on all three axis linked to the DROs. This all coupled with the ability to easily tell the machine where to go and then have it go there. How long do you spend eyeballing the job to ensure you have set the cutting tool on your manual mill in the correct position. Bin the handwheels.

Regards
Phil

the

I am new to the forum and suffering from information overload. I am planning on doing a CNC conversion of my Homier X2 Mini-Mill. But, I don't want to lose manual operation of the mill. X and Y seem easy enough with cranks on the output shaft of the dual end steppers, but Z is a problem. It seems that at the very least it should be upgraded to an ACME screw, but that appears to rule out retaining the three-spoke handle for manual drill operations. What is the best solution for upgrading the Z-axis without losing manual operation?

[Bubba]

As for the working of a ballscrew, do a search as I seem to remember an excellent tutorial on this recently on the zone.

But to answer your question directly, NO; the ballscrew nut never (you hope or you will have little balls all over the place) disingage!

[S_J_H]

sorry for the newbness of the question, but how does this work? Does the ball nut disengage?

No, the ballscrew just spins as you move the head with the rack and pinion drive. You see a ball screw is not like normal acme thread. The ballscrew will back drive. For instance on my x3 mill which is all ballscrew I can push hard on the table and make it move.
The factory rack/pinion x2 z axis drive with an additional ball screw drive work fine together.
There are times when I'll use my x2 mill manually for super fast small milling jobs that might be finished by the time I booted up the pc, or for special things like indicating a bore as it is easier by hand since my X2 suffers from .003" backlash. But I would say don't worry to much about manual operation as the better you get with cnc the less you'll ever want to turn a handle. I use a cheap PC game pad with Mach3 for simple "manual" type control and then MDI for precise "manual" control.


Steve

[fatal-exception]

With a little enginuity, you can make a precision z-axis for your mill. I have the same chinese one, and just finished making a 'cnc z-axis' for it, yet leaving all the other manual features intact. (I still need to use it as a manual drill press for the time being...) I can engage and disengage the z-axis precision drive at will by locking onto, or releasing from the leadscrew. It's not a slpit nut design. I'm using an acme delrin nut, but you could probably use a ball nut in the same idea.

I will post some pics within the next day or so...

Paul