Cam Switches

[video width="272" height="480" m4v=""][/video] I decided to combine my Pcomp and Intro to Fab projects for this week.

I knew that I wanted to build something for ItF that would require me to make compound cuts on the miter saw (something I've never done before), but wasn't quite sure how to integrate that into a switch. I was reorganizing some climbing gear on Sunday when I suddenly had the idea to build a switch that would be connected by the lobes of a cam.


I drew up a design for an open frame with metal on the inside. When you insert a cam into the frame, the circuit is completed--lighting up an LED on the top of the frame:

I initially tried ripping a 2x4 on the bandsaw, which didn't work out well:

I ended up switching to some scrap 1" plywood I found and cutting 3" sections on the panel saw:

From there, I setup the miter saw to cut at a 45 degree angle and created a backstop to cut the sides:

Final miter saw cuts:

Pretty rough around the edges, I did a quick pass on the belt sander to smooth most out:

Next, I used the drill press to make holes for the LEDs on top:

All drilled:

I mounted the LEDs into the holes, bent the cathode to one side, and soldered a longer lead to the annode:

I then glued up the bottom 3/4 of the frames:

I used an extra side piece to form and cut the foil:

2 pieces of foil were placed on the inner sides of the frames before I glued the tops on:

At this point, I tested them using a AA battery holder:

[video width="272" height="480" m4v=""][/video]

I then glued the positive wires to the frames:


Added batteries in series, hot glued + taped:

It works, but the connection sucks:

[video width="272" height="480" m4v=""][/video]


  • Miter angle cuts are hard to get right, need to practice more with this
  • Don't expect to make straight cuts on the bandsaw
  • Taping batteries together sucks, never do this again--use battery holders
  • Need to give myself more time for these projects