Originally Posted by
Adobe Machine
Even using double ball nuts, I still stuff the front ( fixed, the one with the flange ) baLL nut with oversize balls ( chrome steel, 52100, grade 25), and just use the factory balls in the tension nut ( the tension nut does not drive, it only puts tension on the ball nut and the shaft )
In the pictures below, you can see how I set up to reload ball nuts.
1st I set the shaft in the lathe, and clean the shaft. Next I empty the factory balls in one container. I measure at least 30% of the balls, to determine if they loaded with oversize or staggered. They did not, all factory balls measured .1248 to .1249..close enough. I then prepped 2 dishes for oversize balls (.1252 and .1253) and marked my table that I use under the shaft for tools and to have a "catcher" plastic dish in case one gets dropped ( only 2 today). Then I load the empty ball nuts and hardware on the shaft and remount on the lathe...I shift the lathe in neutral and turn off the electrical to the lathe OFF as a saftey item. I begin loading, one ball in each, turn the chuck while holding the nuts and watch the balls disappear, keep loading and turning the same direction. I do keep the nut wet with oil, putting a little in every 3-4 balls.Pretty soon you can see balls appearing in the other side of the circut, do not let them go past where the tubes go in, they will forever be in no mans land and not recirculate !Next, use vasoline ( if a cool day, grease if a hot day) and fill 1/2 of the split recirculating tube with balls, then press the 2 sides together and install on the nut.I do install fastners at this time. It is important to turn the ball nut through the entire range, see if binds or jumps, or is loose. This was not any of the above, no the next step is installation of the shaft on the machine.
Picture 1 : My way of settting up and organising to stuff balls.
Picture 2 & 3 : Unloaded nuts and hardware on the shaft.
Picture 4 : Containers and tools
Picture 5 : Almost done
Picture 6 : Done
Picture 7: After running up and down the shaft, now ready for install.
Next : Installation of the ballshaft, testing for backlash, torquing fastners,and running the Z axis through the full 33" inches.
Adobe (old as dirt)