Originally Posted by Deviant  Ok, so I got the dial indicator out.
I have 0.005 backlash on the y-axis. From either the anti-backlash nut, or the handle.
How much should I have. Is that good? It's spot on if I zero and don't change direction. On direction change I'm loosing .005".
Also, I haven't lapped the x-axis, but I'm getting about ~0.002" if I shove the table, and about ~0.002" if I tug on the table. For total table shift of ~0.004" When the table is centered within it's backlash range. I wanted to add, that I have snugged down the x-axis so that it can't move. That 0.004" play appears to be in the y-axis somewhere.
Is this good? I'm not sure how to adjust that out, if it's the backlash of the screw letting the table move back and forth. I have the gibs adjusted to where the table will move slowly with no real side to side play. I could tighten them more, but if the movement is in the screw, that wouldn't help much. Would it? I've snugged the anti-backlash nuts down, but I haven't really put any torque on them. Just good and snug. |
.005 is not bad at all. You might even be able to get a little less if you tighten the nut to preload the thrust bearings, mine was not really preloading when I got it. Do not crank down on it, this just makes life more difficult on you and the bearings.
When you say shove and tug, do you mean you are trying to rock the table around to test for play in the table itself? This can be solved my tightening the gibs. Don't crank down on them. Just tighten them until you just feel the resistance, then get the locknut.
Every manual (acme screw) machine will have backlash. If you are experienced, you will be able to compensate for the backlash while operating the machine and get excellent results. If you are not so confident, I suggest a DRO. If you plan to go CNC soon though, I would say it is not worth a DRO. If CNC is something you plan to do in the long term,you really might want one.