Cleaning fiddly bits and fighting snap rings

A project log for Rockwell Milling Machine Rebuild

Rebuilding a Rockwell 21-122 Horizontal/Vertical Milling Machine

polyfractalpolyfractal 12/15/2017 at 17:400 Comments

Part two is up!  This episode is mostly cleaning the quill fine-feed control, the head rotation mechanism, cleaning the bearings and wrestling with the pulleys.

One interesting thing I found was the worm wheel in the head rotation mechanism.  This mechanism allows you to tilt the head left/right, so that you can make angled cuts.  You adjust the tilt by turning a nut, which internally rotates a worm against a worm wheel.

What's interesting is that the worm wheel is made out of aluminum, while the worm gear itself is steel.  The worm wheel is the piece that takes any rotational forces induced by the cutting action (assuming the force is too large for the locking bolts).  So there is a chance of shearing or mangling the aluminum teeth if the head takes sufficient sideward load.

I'm unsure why Rockwell chose to make this gear aluminum... perhaps it's a sacrificial part?  If something goes wrong, you'd rather destroy the worm wheel and replace, rather than the worm gear?  Not sure.

In any case, I'm expecting one more video in this series; stoning the table, masking everything, priming/painting and then re-assembly.  There may be a followup video with things like installing DRO, etc.