which axis should have the best bearings

[nicanor76]

If I'm slowly upgrading my homebuilt CNC (skate bearings, open table, moving gantry with 2 motors on the X) and slowly replace them with real industry linear bearings as budget permits, which ones should I upgrade 1st? I'm guessing in reverse alphabetical order, the Z should be 1st, then the Y, right?

I'm running 269oz motors on each axis BTW. Also I'm planning on getting 16mm fully supported rails w/open bearings. Table dimensions roughly 24"x24"x8".

Thanks!

[nicanor76]

anyone? I'm sourcing parts and because of my budget (and sources found) I'm going with:
2 axis of unsupported 3/4" precision rod w/closed bearings
2 axis of full supported 16mm linear rail w/open bearings

Which rails would be best for which two X axis? The 16mm supported rails for the X since it it will be holding the most weight (open table, moving gantry)?

[m1911bldr]

I woudl upgrade the bearings by weight and forces. X would be first since those bearings carry the full weight of the gantry and all the associated forces. Then Y, since it carries the weight of the Z carriage and its forces. Finally the Z, since it's weight is teh minimum carried and the forces are directly from the spindle/cutter.