This hand switch was designed to work with an auto paste dispenser we found on Amazon. I would assume that any other model that uses a 1/8" jack as a switch would work as well, but no guarantees :)

It ships with a hand switch for a 150CC syringe, however, in the Adafruit shop we like to use smaller, 30CC syringes. That's where 3D printing comes in.

Remember, an air compressor is required for this tool and not included!!



  1. Tactile Switch
  2. 1/8" Headphone Jack
  3. 1/8" Audio Cable
  4. Two 4-40 nuts & screws (Approx. 1/4in, not sold from Adafruit)




Print the two sides using the STLs in the download link above. Also included is the Rhino .3dm file for any edits.


With this particular model (and I would assume any other that uses a 1/8" audio cable) the dispenser is activated when the ring and tip are shorted. 



Using as thin a wire you can find, solder the switch to the tip and ring of the 1/8" jack. Bend the leads underneath so that they fit within the enclosure, and screw the two sides together.


Tighten once around the syringe!

This guide was first published on May 08, 2015. It was last updated on May 08, 2015.