Update 2024-10-12: Added new NEMA 23 mount that really beef up where it joins the 4040. The old mounts ran for a decent amount of time, but eventually came apart on the 4040 side.

The distance on the inside of the mount (the 23 to the 4040 face) is 53mm. This may or may not fit your motor depend on shaft and coupler size.

UPDATE 2024-07-24: I've added a little clip that covers the flange nut and removes the gap for a smoother transmission. After running for a few weeks, the flange developed some grooves from the force of changing direction inside the vslot.

*There must be a better way to design this to eliminate supports without adding too much more material and still keeping the access to the coupler.

These mounts allow for a stepper to be mounted to vslot 4040 to make a linear actuator. Inside the 4040 is an Igus 1/4" high helix lead screw, with their square flange nut. The nut fits inside an 18mm aluminum tube with an ID of 12mm.

The inline version is easier and cheaper to build than the pulley version, but obviously depends on a plastic motor mount. The nema17 mount has been run for a few hours, but the nema23 has only been assembled, not run yet.

The igus screw and nut runs around $35. Add about $15 for the vslot and bearings. The line video will be uploaded soon. Video of the pulley version:

https://youtu.be/fm0g7oYxJB0