Experimental spectra line drive (failed)

thingiverse

Testing of a drive method for 3D printer with spectra line. Grooves in drive pulley are parallel as is the idler roller grooves, the idea being that the angle of line going to the drive will never change no matter where how far it's "wound" up. Normally if just wrapping the pulley, it acts like a screw and causes the line to climb or lower on the pulley. I did not get any photos but I also tried crossing the wraps between the drive and idler roller to slightly boost the contact area on the drive pulley yet gained no reduction in the gradual error. This failed because no matter the number of turns or line tension, I still had a slow gradual loss of position during printing. However, I'm still posting this as it could still be useful for a camera slide or linear motion system where perfect repeatable position is not needed. STL files are mostly for reference; idler side had a bolt and a bearing on the top and bottom. Video of the motion: https://youtu.be/9TBoSpT2unQ How I Designed This Inspired by Rob Povey's blog at http://3dprinterhell.blogspot.com/2013/06/a-better-filament-drive.html Also a video by Rikard Hamrin, youtube.com/watch?v=pKerL-opsj4