This video shows an inline Openbuilds VSlot 4040 with a Nema17 stepper motor. At the end, there's a pic of a Nema23 version. It uses much of the same hardware as the pulley version:
• How to Make a Linear A...
00:15 Start of motion / app control
00:45 Stroke length shortens
01:30 Pic of Nema23
The 3D STL files can be found:
www.thingiverse.com/thing:664...
The materials list for the pulley version is:
github.com/MikesMachines/VCyl...
The main point of the video is just to show the design. I'm using Blynk to control via app. While running, it allows changing the speed, stroke length, acceleration, deceleration, torque, and can create sequences of programmable motions. Also it can run remotely over the internet.
One thing steppers do very well is vibrate when the stroke lengths get very short, so I thought that was interesting to show. The lengths are in steps to show relativity. It works out something like 200 steps is 1" (25mm). I've been running the Igus screw for hours and it's developed a bit of wear on the nut. This allows the screw to turn a small amount at each direction change. It isn't critical for my work, but you wouldn't want to put this in a CNC machine.
After letting these machines run for a few hours, I've done some improvements with bearings that have made the motion much smoother. Hopefully I'll have a 'final' version available in a few weeks :)