Showcase Showdown – CNC Machine Limit Switches
While the shakedown of my Nimitz-class super CNC machine continues, here’s a look at how I rigged the limit switches. As a side note, shakedown refers to finding a way to keep the shaking down while moving the gantry, but more on that later. I picked up plenty of microswitches with rollers from eBay, just the cheap Chinese variety. Then made more custom brackets from HDPE plastic I had lying around.
The Rockcliff controller board was easy enough to connect to the microswitches, but required .1 uF cap to ground for the three axises and E-stop to cut down the noise. Each axis shares two microswitches at each end; the software sorts out which one by the direction it was traveling, supposedly. For saftey’s sake, all the switches and E-stop are active high and use the normally closed side. This setup will prevent the machine from running if there is a wiring fault, like a wire break then crashing.
I used two conductor, stranded and shielded cable for any wiring that was stationary and threaded through easily accessible hollow places. A stretchy surplus keyboard cord was used for the section that moved, as described in the previous post.
So, yeah. Now it’s all about getting the settings for the Mach3Mill software right and then on to preparing for the first cut. I’m thinking of rigging up a pen for the initial trials…