I have a Seig KX1 (LMS version) and all of a sudden it is behaving strangely cutting circles.   The top and bottom of the circle is flat rather than a smooth circle.  It is like at the top and bottom the y axis has stopped moving.  This is repeatable and is always a perfect horizontal flat.  I have adjusted the gib on the y axis but it is still the same.   Is there anything else that could cause this?

Thanks


David

David, that is a perfect description of Y-axis backlash. But since it happened all of a sudden, then that implies that something in the y-axis has suddenly come loose. Perhaps jogging the Y and watching/listening may help find it.
This assumes that you didn’t originally have backlash and were using backlash comp. That’s another story.
HTH Al

No backlash or backlash compensation.  I think it might have been the gib, as I removed it completely, cleaned it and re-inserted it and from a quick test cut it looks better.

I will test further tomorrow,

THanks

David

If by top and bottom of the circle you mean you have lines running parallel to the X axis then your Y gib isn't going to cause that.  The Y gib constrains motion of the Y axis.  If it is loose or misadjusted the Y may tilt, giving you strange results, but not a line parallel to X.  Unless it is REALLY loose, then the table could shift left or right, but I would think that much slop would be an obvious cause for concern.  A far more likely scenario is that something else came loose, either your mount of the screw to the base, your nut to the saddle, or possibly your bearings in the screw mount block.   

 Hii

I am also same problem. Did you solve problem in mach3 or mechanical adjustement

thanks

Saki