suggestions, are the same, I probably was unable to articulate what I meant.
If you have Acme screws (assuming you do since you didnt say otherwize).
On the X axis at the right hand side, use the backlash nuts and tighten it up, to take out what you can.
Here's the thing, what I was trying to tell you above is this:
lets say starting a x0.25 move your axis from there to X0 (or just move it about 0.25 inches. Now where ever you are after the commanded x move 0.25 zero your dro. Then STILL moving in the same direction (moving in a negative direction), command a move from x0 to x-1. Note what the dro reading is (it may be even more accurate to set up your Caliper to varify the accuracy of your dro as well). Now go from where you axis stopped at x-1 a little further lets say another -0.25. don't worry about where this is on the dro, this is a turn around point. NOW move your axis Back the other way, moving from - to + by about 0.25 (these little moves make sure that all the slop/slack is out of the axis). Now REZERO your dro, now moving in the same "Back the opposite way", direction, command the move from x0 to x1 then measure your dro... The two measurements that you get one moving positive and one moving negative will be the real results of your motor tuning, if they are off (with the backlash minimized since you have started axis motion in the direction you wish to measure prior to measuring it), then do your calculations to get it going a true 1" (again moving in the direction you plan to move further in, prior to moving in that direction).
Once you get true 1" THEN do the back and fourth moves, i.e. but do them like this: move in a premove direciton first a short bit to take out lash, then send the axis from 0 to x1, THEN move from x1 back to 0!!! Record the dro, the amount that you are off at this point will be your (change direction), backlash, on the X axis on acme's it is about 0.006-0.011 per foot. with Ball Screws it is about 0.004/foot.
NOTE: the back lash compensation only works with staight liner moves, and then not real well. It has NO effect on CV/3D stuff.
I would highly recommend Servo's and Ball screw/nuts, also take a real, real close look at your gibs and the squareness of your table. Beware that you will have to put some work into the machine to get what you want. I can get NO measurable backlash in objects under 6" cubic envolope. BUT, when you goto larger objects, then you get about 0.004-0.005 per foot or so.
if you STILL get stuck, or what I am saying doesn't make sense, then send me a email to:
poppabear@hughes.net and I will then send you my number and I can try to talk you through the issue.
Understand: the machine is NOT a bridge port, but given workpieces that fit into its working envolope the machine is not bad. I have never had a part (yet), that acually required less than 0.005" tolorance as of yet...
Poppa