Cutting parts for the “Meticulous Z-Axis”

If you look on the Maslow CNC forums, you will see that one of the greatest challenges that Maslow users face is the mechanics of the z-axis. The height adjustment on the recommended router, the Ridgid 2200, was never meant to be used in the way that it is on the Maslow. It can be altered to be OK on cuts with a limited number of z-axis moves, like furniture. But if you want to do something with a lot more depth movement, like some kinds of artwork, such as my CNC Halftone experiments or logos, it can start to get dicey. My guess is that the main issue is the accumulation of errors due to slop in the router’s height adjustment mechanism that the Maslow uses for z-axis moves (not an original idea).

3D halftone image experiment
Serifs & Whiskey logo

I should state before going into the things I’ve tried, and the recommendations I have that I am not an engineer of any kind (although my last job title before becoming a full time maker was Desktop Support Engineer). Also, if you are a Maslow user, or thinking of becoming one, you should definitely go to the Maslow forums to get answers and advice from people who are far more experienced in this stuff than I am. My general approach to the Maslow is: I have technical skills and the Maslow is within the range of those skills, but I’m really more interested in the art I can make with it. Upgrading the machine was done out of necessity, and not because I wanted the engineering challenge. Making halftone images, for example, was something I had in mind to make from the beginning, and I did not know I’d be pushing the limits of what the Maslow can do.

There are a number of ways recommended on the forums to take the slop out of the z-axis mechanism on the Ridgid router:

  1. Add a some elastic over the top of the router and anchor it to the sled. In my opinion, this should not be an option. Everyone on the forums will remind you to not put too much tension on because that might cause the router spindle to slip out of the shallow slot that connects it to the z-axis mechanism (what I learned is called a “mechanical fuse”). I have found that it is not too difficult to achieve sufficient force to take out most of the z-axis slop without causing the mechanical fuse to trip.
  2. Another easy get is putting a thin washer under the screw that the z-axis mechanism rides up and down on. The entire screw can slide a good millimeter or so, and the washer pretty much eliminates this source of slop, and it’s easy to do.
  3. Attach a bushing to the z-axis clip to keep it perpendicular to the screw. This is something that didn’t work for me and caused the mechanical fuse to trip, I suspect because I used my own solution, but I’m not sure. I suggest that if you want to go this route that you carefully follow the instructions here:

The other solution to the z-axis problem is to discard the Rigid router mechanism entirely, and build a replacement one. That’ll be Part 2.