The design is based on that ubiquitous Gear Bearing test print that you often see displayed at 3D printing shows, but a maker and blogger has converted it into a functional peristaltic pump that can be used for any sort of build where you need to precisely move liquid from one place to another automatically.
A peristaltic pump works by feeding a flexible tube into one end of the pump mechanism and out the other, as a centre wheel moves, small rollers pinch one side of the tube closed, trapping fluid in it. As the rollers turn they push whatever is in the tube forward in a relatively continuous flow. At a basic level, it works the same way as your intestinal track, hopefully just with less poop. Peristaltic pumps are mainly used for medical applications, however an industrious maker should be able to find plenty of useful applications. This one will most likely end up in a greenhouse to control water flow for an aquaponics set-up.
On his blog, Tim detailed how he was inspired to create his pump by a Planetary Gear Bearing design that can be found on Thingiverse. Like the gear, the peristaltic pump prints complete as a single piece – even the moving rollers – so there is no assembly necessary beyond inserting the flexible tubing.
The pump is driven by a standard ¼ inch hex nut, however you can easily customize the object to include the type of moving mechanism that you need for your build. You can see it connected to a drill in this video demonstrating the pump in action:
Tim designed the pump in OpenSCAD and you can find his OpenSCAD file here. He said that the pump is completely parametric, so you can adjust the diameter, height and the geometry of the tube channel if you need to.
