RE: [CAD_CAM_EDM_DRO] .0055 of play in the z-axis

.0055 slop on a new Chinese made knee mill is pretty good. My enco knee
mill came stock with .020 backlash on the Z axis, .010 on the X and .008
on the Y. Since your backlash is that much I would recommend trying one
of those gas springs to take the backlash out. Alternatively you can do
what I did which was to put a servo motor with a 4/1 ratio on the knee.
I have used this set up for about 4 years with no wear and it is easier
than trying to modify power head.
You didn't mention how much backlash was in your XY axis.
Dan

-----Original Message-----
From: jbordens [mailto:jake@...]


Basically, I've got about .0055" of play according to my indicator.
This number was obtained by using the fine feed crank to move the
spindle down mabye 1/2 of the way down. Then, I set the indicator on
a flat portion of the underside where the collet goes. Next, I press
firmly upwards from the same place... And the indicator shows a
little over .005 of movement.