Hi,

I have a Harbor Freight X2 that I converted to stepper motor CNC operation a year or so ago. I haven't used it much because of constantly losing steps and scrapping my projects. I finally turned my velocities and accelerations way down, but I am still unhappy with how the gibs move. I have to choose between tight and veeerrrryyyy slow or fast and loose.

Anyhow, I have been researching linear bearings and am curious whether anyone has used them on a milling machine in place of gibs. I was thinking round rails with continuous support mounted on an extruded aluminum T slot type frame. I see tolerances around .001" on the suppliers' websites, but I wonder how they would stand up to chatter and general milling forces.

My thought is to mount the table on the Y axis, then mount this all on the X axis, which would be on the bottom, mounted to the t-slot tubing. I think this would allow me to mount the Y axis with the motor in back, and allow me to mount the X so as to make use of the entire table. I would also like to extend the spindle head out a tad and increase my Y while I am at it. I would also mount the Z on linear bearings attached to rails on T-slot framing.

I am currently using 5/8" Thomsen ball screws and nuts, but am considering using an Ebay kit to replace all 3 axes' ballscrews, since I've lost several balls out of all 3 nuts while messing with them. Does anyone know if you can buy replacement ball bearings for them?