CAD CAM EDM DRO - Yahoo Group Archive

ball screw on linear bearing stage, was 9x20 CNCing

Posted by Elliot Burke
on 2004-09-22 07:40:40 UTC
After lapping the cross slide on my 9x20, I'm still not happy with the
smoothness of the motion. Maybe a finer lapping compound would help, maybe
I'll try that today.

The backup position is to put a linear ball slide on. It has a 6" travel,
weighs about 10 lbs. Hope it's heavy enough for some light grinding. Will
check it out with indicators today to make sure it's tight.

It has no obvious provision for ball screws; there are no mounting holes on
the ends, no hollow in the middle. Am thinking the ball screws could either
be put along the side or on the end.

If on the end, the whole length of the ball screw (10"?) will stick out, and
a mount will be made for the ball nut to hold it far enough away from the
end of the stage. This would minimize abbe offset error.

If mounted on the side, it would probably be opposite the side where the
grinding is. This would be a more compact mounting, but I'm worried that
the abbe offset error might comprimise accuracy. Will measure the
straighness of travel using an interferometer to see how much of a problem
this will be.

Will post pictures of the interferometer if anyone is interested.

The object of this is to make a lens edging machine; lenses will be
accurately made round to diameters tolerances in the several micron range,
the lens axis will be collinear with the lens edge to similar tolerances.

Elliot
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Discussion Thread

Elliot Burke 2004-09-22 07:40:40 UTC ball screw on linear bearing stage, was 9x20 CNCing