Removing the Z backlash on my King PDM30 (RF 31 style) round column bench mill

[Canuck75]

Sorry, nope no adjustments on the springs.. Just cut to length I guess if thats an issue.

The quill shaft, the one with the pinion gear on it that runs the 'rack' on the quill does NOT come all of the way through the casting, since there is no coil spring attachment on the left side.

Here is the right hand side:

View attachment 72467

No power down feed and your normal 'fine feed' worm drive assembly. Also here you can see that the column clamping is in FRONT of the column. This casting is NOT split and squeezed together. There are two blocks on each side of the column that press in on the side and front of the column to lock it. I've no clue if this is better or worse that other designs. On my todo list is a complete tear down and clean up. I got it used from a factory and there is old dried gunk on the table ways and the column has gunk on it. I need to get the engine hoist - Cherry picker back from my buddy to lift the head and column off.

(Gray rectangles in that picture near the base are plywood that has spots on the other side for R8 shanked tools. Whoever built these "plugged" them into the 2 rear mounting holes and you can swing them in and out to make space around the mill when working.. )

Thanks for the extra information and the picture. I don't see the fixed length return springs as a problem either but just thought there might have been an adjustment mechanism available. Regards the column clamping arrangement I don't know which is better either. Mine has a split casting and is clamped from the rear. I do know from experience that this can, at times, torque the head a bit when tightening and I always had to reset my X after any head movement. Actually, that issue of keeping the X is what resulted in me pinning the rack to the column and bolting tight fitting guide blocks to the head to ride along the rack to keep the X. I don't worry about raising or lowering the head during operations now as this is no longer an issue for me.

With regard to removing the head, on mine I had unclamped it and tried lifting it up the column as a unit only to realize just how heavy it was. I didn't have a hoist either so my solution was to strip the head totally in situ since I was going to tear it apart anyways. After that it was quite easy to lift the bare head casting off by hand and afterwards, to reassemble it in reverse order - for what it is worth.

Anyways, nice machine.
Canuck75