gantry getting real tight about mid table

[bigcreek]

Ive got a Sampson table and on either end of it the gantry moves freely and easily but at center and about 18" on either side of center it gets real tight, and I mean real tight. Tight enough that it is difficult to move it by pushing on it. It was always a little harder (but not too bad) in the center but it has just as of late gotten real hard to move. If I am cutting at real slow speeds it cant hold its position and goes off course. I will take it apart here pretty quick to try to fix it but does anyone have any thoughts on what could be causing that to happen?

Thanks,

Josh

[jmsrbrt]

I don't have a Sampson table, but I'll throw this out there for what it's worth...I did a little clean up on my machine recently, tightening everything, checking belts, etc., etc.. One thing I did was adjust the motor on the Y axis a little tighter to the gear rack (you could wiggle the torch left and right a little. After tightening, the wiggle went away.) Well, fired the equipment up and started my first cut. I usually move the torch on the X and Y axis first just to make sure everything is kosher. Well it wasn't. The torch was hanging at the same point on the Y axis every time I jogged it. Checked the usual culprits, and what I finally came up with was the gear rack may have been a little warped, causing my "tight" adjustment to bind at that spot. A little manipulation on the motor mount, and I was able to get rid of the binding, and still not have the wiggle. Just a thought.

[bigcreek]

Good thought it is as I was thinking about the same thing that it likely has something to do with the gear rack(s). Thanks for your input.
Josh