Introduction: Mostly 3D Printed Slider Switch

About: A retired software developer, living in Waterloo, Ontario, Canada, who appreciates having the time to make whatever the heck he damn well feels like!

I am currently making a vintage computer based on the book "How to Build a Working Digital Computer" by Edward Alcosser, James P. Phillips, and Allen M. Wolk. For more information on my project see WDC-1 a "Working Digital Computer".

For this project I require a 5 position panel mounted switch. Based on where the switch will be used I decided that a slider switch would be ideal. Employing some of the techniques learned making my Mostly 3D Printed Rotary Switch, I came up with the following 3D printable design that uses reed switches and magnets.


In addition to the printed parts you will need the following:

  • 5 Reed Switches - Digi-Key part number 2010-1087-ND
  • 7 Disk Magnets - 6 mm (diameter) x 3 mm (height)

Step 1: Print the Parts

I printed the parts with the following settings:

Print Resolution: .2 mm

Infill: 20%

Filament: AMZ3D PLA

Notes: No supports

To make the basic slider switch you need the following:

  • 1 Slider Switch (STL contains all three required parts)
  • 1 Slider Knob (optional)

Step 2: Assemble the Parts

This is pretty straight forward:

  1. Insert the reed switches and magnets into the Slider Base. Make sure that the magnets are all inserted with the same polarity.
  2. Place the Slider Gasket on top. I like to make sure that the smoother first layer side is facing up.
  3. Add the two magnets to the bottom of the Slider Knob. The magnets must the inserted with the opposite polarity of those in the Slider Base so that they will attract when in use. You may need a drop of glue to hold them in place.
  4. Drop the Slider Knob into the slider base.

You should now be able to slide the knob all the way to the top and bottom of the switch. You should feel the 5 "stops" as you do so. If this doesn't seem right, rotate the knob 180 degrees and try again. You'll know when the knob is properly oriented.

Step 3: Install the Slider Switch

The first picture above shows the slider switch installed onto my WDC-1 project panel with a couple of M3 bolts and nuts. The second picture shows the full panel with the optional "fancy" Slider Knob installed.

Step 4: Testing

Connect a multimeter to the leads of each reed switch. When the slider is above the connected reed switch the multimeter should indicate that the circuit is closed. Conversely if not pointed at the connected reed switch it should show an open circuit.

Step 5: Final Thoughts

Here is a video of the slider switch in action:

I'd be very surprised if anyone actually needed a slider switch exactly like the one I have described here. I do hope however that the ideas outlined here will be generally useful for anyone with a similar need.