Millhead alignment

[FloridaClay]

Hello all,

I'm in need of some help with the millhead on my Eldorado. First, let me say that I am very new to the mill business.

I need some help with the millhead. It appears as though the previous owner has lost a nut for the screw that attaches to the stepper gear (see pictures). The mill mount is down so far that a nut can not be put on the screw. Is there a way to easily reverse the screw (I tried by hand but didn't work) without hooking a computer to it and trying to run it down?

Also, the manual that the previous owner handed me is rather crude. Is there a better manual available?

Thanks for any help..

[dgapilot]

The screw should be fixed to the lower mount plate, which is attached to the spindle. The pulley is attached to the nut which turns on bearings in the upper mounting plate which is attached to the head. When you turn the nut, the screw moves up and down to move the spindle up and down. Hope this helps.

[FloridaClay]

Dgapilot,

Thanks so much for your reply. Is the screw attached by a nut or attached some other way? Upon further inspection, it looks like the mill column was allowed to go too far down without a stop. Does anyone have a picture of an "unmolested" head that I can see?

Thanks

[FloridaClay]

Okay, I get it now, the bolt is threaded into the bottom of the screw in a vertical manner.

Is there anyone in the North Florida area that has knowledge of Shoptask mills that would be willing to come help me get this mill setup (for pay, of course)?

[jrjr.]

FC,

A better attachment method is to add a machinable collar to the
drive screw. And an extension to the drive screw.

This allows the ability to center the driven screw better to the
attachment plate and also allows the release of the drive screw
for manual use.

Some of these weren't done very well on centering the CNC mechanism
and cause binding due to the misalignment of the upper mechanism
to the lower (driven) assembly.

The cnc drive screw was tapped and a 1/4-20 thread and shaft
added to the lower side to allow the machinable collar so that it
can be released when using the machine without CNC.

The z axis return spring must also be properly aligned to affect
a neutral setting for the proper spindle operation.

Watch out for the ball bearings in the driven part, they could fall
out if the mod is not carefully done. I was able to do this with the
outer race still attached to the shaft, in the lathe as one piece
with the race taped down so no bearing loss, and careful clamping
in the lathe with some cushioning (paper) on the clamp.

jack