On Dec 18, 3:11*pm, "Steve" wrote:
...
I've got one of these [RF-30] and it's very difficult to get any sort of accuracy in
"Z" without a digital scale. * Once you've added the scale then plot the
digital readout against the mechanical dial, *you get to understand three
problems - backlash, the quill sticking and non-linearity of something...

Steve

I felt it would be a decent hobby mill for the price with the
inaccuracies fixed. Someone here once described shimming the column
base to square up (tram) the Z axis. I wedged the locating key I made
for the vise tightly into the tee slot and milled shoulders in its top
edge, automatically parallel to the X travel, then slotted the
underside of the vise be to a press fit on it. The table itself
indicated substantially tighter than 0.001" over its full travel.

It wasn't mine so I didn't take it apart. Do you think a cleanup would
fix the quill feed and lock?

jsw