Many pneumatic stepper motors, rotary engines and other pneumatic devices were developed during my research. Several were published in research papers and/or 3-D model websites. This page lists nearly all of them, alongside with the most important properties and a link to the downloadable model (if available). If a motor design is not yet downloadable then you can send me a request for it.
Certain motors have extensive printing and assembly instructions and/or a video compilation. If you are interested in 3-D printing one of these motors then there should be plenty of information and designs to start with.
At the moment I subdivided the motors into five categories: linear, rotational, curved, rotary engine and dual. The motor name consists of a character (or two in case of dual-speed) plus a number and sometimes a postfix.
First character(s): T=linear, R=rotational, C=curved, D=dual. The following number indicates the major dimension (length or diameter) of the motor, in mm. The “B” postfix indicates a redesign of an existing model.
In theory it is possible to scale any design along (some combination of) its axes. This should work with some experimentation.
If you need help with a motor then you can post a comment on the associated Thingiverse or MyMiniFactory webpage, and I will look into it. You can also contact me directly at firstname.lastname@example.org. If you designed something cool based on these designs then I am always happy to see it!
Designs are for non-commercial use only. Contact me for IP related questions.