CNC Upgrade :: z-axis (part 2)

Once the fixed back plate (3/4″ aluminum) and the movable front plate (1″ aluminum) were machined it was assembly time. Here you can see the parts laid out and ready to go. In the upper-right you’ll see two white brackets to mount the stepper motor and tension the belt. These were 3-d printed with the mindset that I’ll mill aluminum ones when the machine is up and running. I found out about the option to put brass screw inserts in the 3-d print too late, but it looks like an awesome procedure and is something I’d do in the future.

Assembly was pretty straight forward. I did have a little binding on the lead screw and had to shim it out a little bit using some folded aluminum foil. Shim stock isn’t something I have on hand!

Minor shimming required where the ball screw attaches to the moveable plate.

And some additional photos of the assembly and mounting to the y-axis.

Once it was on the machine I could locate the z-axis homing switch. I used a fairly inexpensive magnetic sensor from amazon. I mounted the sensor in the back plate, and then drilled/tapped and threaded a hex-cap bolt in the movable front plate. This bolt triggers the magnetic sensor when the z-axis is in the full-up position.