Ballscrew mill table removal?

Hi,

I'm getting a new Prototrak mill and to get it into my shop I need to remove the table. I have had several knee mills totally apart, but I understand the ball screw should never be separated from the nut.

I need a sanity check...if I remove the right hand bracket with the handwheel and the other end with the servo and also the gib I should be able to slide the table off leaving the screw in the nut attached to the machine. Is this correct?


I found this old post saying that but I want to make sure of it. I will be doing this in a dimly lit warehouse so I want everything to go right.


Posted by J Henricksen in 2008

"Removing the table is the same as with regular screws, remove the end bearing supports, pull the gib, and slide the trable off the saddle leaving the screw in the nut on the saddle. Take the nut and screw out after the table is off. To take the nut off the screw, Rockford Ball screw uses cardboard sleeves that keep the balls in their channels in the nut. I've used alu tubing wrapped with vinyl electrical tape too. If you are going to do a screw rebuild, you can remove the nut from the screw and catch all the balls in a pan. Count the balls, and put half in one channel, the other half in the other."

Can't imagine wanting to take the ball screw and nut apart!

Loosen the gib, remove the end bearing caps, servo mounts, etc
Slide the table off, Then remove the nut with the screw still in it.

Leaving the ballscrew in place won't gain you any more clearance with the table removed.

You should be able to crank the table far to one end, enough so that you can remove the bolts retaining the ballscrew nut. Then pull out the ballscrew with the nut still on it.

Beware that the nut will freewheel and come off the screw on its own if you tilt it too much. Wrap some tape around the screw on either side of the nut to stop this from happening.

If you need to remove the screw, then just take the bolts that hold the nut into the yoke and remove both.

Jon