CNC Router Build
I decided that I wanted a CNC router, and that I ought to build my own.
I designed the router in Fusion 360. I had a few specific design goal in mind, including:
First things first: I built this table ahead of time. I needed bench space for other projects, so it made sense to build the router on its own bench from the start.
There’s lots of good options to build your own linear motion rails and axis drives, but for simplicity and accuracy these relatively inexpensive ball screws and linear rails from China are wonderful. Using these parts saved a tremendous amount of time.
The X-axis rails are screwed to the bottom of the table. I screwed one in place, and then used a pair of match-cut MDF spacers to ensure the second rail was perfectly parallel to the first.
These spacers on the x-axis give some clearance to add stiffening members to the underside of the table.
The stiffeners were glued in place before the gantry carriage was mounted.
The gantry carriage in place. I was careful to mount it as square to the rails as I could, but there’s still opportunity for adjustment later.
After flipping the table right-side-up, I screwed the top to the stiffeners. Later I added a second layer of plywood to the top for additional rigidity.
The Y and Z axes were built the same way as the X-axis. Shown here are most of the remaining parts, including the gantry pillars.
Alignment is critical, and it was much easier to get it right the first time than to fiddle later on. I rigged up the gantry and secured it in place with clamps temporarily. Here I’m moving the y-axis back and forth with the drill, and using the dial indicator to check that the rails are parallel to the table.
To check that the X and Y axes are square, I drew lines on the table using the axes to move the pencil, and then checked the lines with a square. After I drew each line I readjusted the gantry and tried again. When I was satisfied with how square the axes were, I bolted the gantry to the pillars.
And lastly, had to make sure the Z rails were square to the table before mounting the Z-Axis bed.
I took some care with the control panel to ensure that the noisy power lines were kept away from the (unshielded) signal lines from the breakout board to the stepper drivers. I used Leadshine M542 drivers, which seem to work fine, in conjunction with a no-name Chinese breakout board.
After wiring in limit switches and other accouterments, it’s time to make some sawdust!