I have maintenance responsibilities for The Rong Fu mill which is about 15-20 years old. I am trained as a physicists not as a machinist. So please excuse my lack of understanding and misuse of terminology. This milling machine along with a small lathe are used in a junior/semior physics lab to give the students a taste of what metalworking machine can do.
There was a lot of backlash (0.020'- 0.030' on the hand wheels) in both the front to back feed and the right to left feed. I cut a small hole in the table below the mill and tightened up the partially split leadscrew nut. This reduced the front to back backlash to a few thou. At this point the tightening screw was getting hard to turn and the handwheel for the motion was pretty stiff, so I stopped.
On to the right to left backlash. This leadscrew seems held in tension from both ends, so I tried shimming one end out just a bit to eliminate any slop in the connection between the leadscrew and the table. Next, I tightened the adjusting screw on the leadscrew nut as much as I could and now am down to about 0.015" of backlash on the handwheels. Better but not great.
- Any good ideas as to how to further reduce the backlash in the left right feed?
- How does one tighten up the jibs on this beast? There is a single large screw running the in the same direction and the motion the moves the jib in that same direction.
Thanks Roger Haar