Posix,
I had bearings in there for the lift problem, but then it creates a new problem, and that's why I was asking about lift. (In hindsight I should have made myself more clear.)
If the bearings lower bearings are in there the gantry supports want to run into the rail itself when they are moved forward and backward down the rail. So I took them out.
As for the first design that had the square tubing that option will no longer work because of the legs of the table in addition to the main supports are bent so I have to use rails in order to eliminate the error of the bends.
I thought of something that I am going to try today. I'm going to put the lower bearings back in and remove the set of bearings on the inside of the upper set.
Another issue I have is if the bearings are all tightened down to eliminate skewing of any sort then they are so tight that A) the gantry won't move and B) the bearings will not run true and come off the rail or grind into it.
-Matt |