This is the first prototype of an extruder made specifically for clay. A stepper motor will mount above the extruder and will couple with an auger. When turned, the auger will force clay, or other pastes, through a 1.5 mm nozzle. The boxy reservoir on the side has a spherical chamber and is threaded for a small plumbing fitting; this will accept a tube through which clay is forced. I can control the flow rate of the material, but I don't yet know if the auger's threads are aggressive enough or too aggressive to move clay effectively. Once I settle on an auger design, I will likely order a version printed in stainless steel.
While this is a custom design, it is inspired by Tom Lauerman's Bricoleur Clay Extruder: https://www.thingiverse.com/thing:1413969 . His extruder is clearly very effective and, truly, a little more straightforward than mine, but I couldn't help but try to start from scratch.