So my friend really needed me to get that part that started this whole project done, so I made I push this week to get all of the get all of the lead screws connected, router mounted, and reconfigure LinuxCNC for the new machine. I wanted to get the hold down table and spoil board on and leveled but didn't have the time so with minimal testing I just put some Styrofoam under the 4x4 1/2 ABS and went for it. Cut 2 parts 1st one was a 30" disc that is used to stiffen the lid of a 36" round ABS barrel so a pump can be mounted on it, the other was a 35" grate that goes in the barrel to support filter media for industrial water treatment. The grate took about 2 hours 15 minutes to cut using 1/8" spiral bit @60 ipm with 1/8" passes, the bits I am using are really cheap ($1.50) and think it is pretty much spent. The only real issue I think have is that when the carriage is in the center of the X axis I can lift up at the router collet and get about an 1/16 to an 1/8 inch of movement which I think is the board of the X axis flexing/twisting, it is rock solid near the sides. I am going to try adding 5 to 7 pieces of aluminum angle or other material front to back to stiffen up the board and see if that helps (any suggestions are welcome), if not I guess I will redesign the gantry.
The bearings themselves worked well, when adjusted so that all bearings are touching and do not slip when held while trying to move them, they are a little tight but I can still move them with just a little pressure and can move the gantry about 1/2 the distance with a modest push, I have no reservations about using them in any orientation once they are locked in. Next steps will be to stiffen the gantry and put the hold down table and spoil board on.