Of the things that show up while I browse Thingiverse for something cool to print, peristaltic pumps keep coming up. It’s a pretty interesting concept, squeezing a tube to pump a liquid. One of its best features is that liquids only ever come into contact with the tubing so it’s really good for corrosive liquids. Seeing as I needed a pump to help me transport my super corrosive PCB etchant and also to bubble air through it to rejuvenate it, this was perfect.
My design philosophy focuses on aesthetics and functionality but, especially when it comes to prototypes, ease of manufacture matters too. I like to not cut screws down if I can because I either have to use my Dremel or rethread the ends. I also like to use up the existing parts I have at home because otherwise they’ll just sit there collecting dust. That meant that I couldn’t use any of the designs online, so I modeled my own.
As expected, the print and assembly process was straightforward. I was quite surprised with how well the pump worked, especially with how little torque it took to drive it. I used a stepper motor because I wasn’t sure what kind of torque the pump needed. Well, based on the design I was pretty sure it was low, but I wasn’t sure how low.
One of the things I needed to do was filter my etchant because I accidentally left a board in too long, like forgot about it and went to sleep long, and everything came off. Ever since then there have been quite a few toner particles in the etchant, but after a couple minutes pumping the etchant through an aquarium filter, it was perfectly clean.
Here’s a video of the pump in action.