I used this as a flexible coupler on a NEMA23 motor with 1/4" shaft to a 1/4" screw shaft. I had originally purchased some rigid shaft couplers but, they were transmitting way to much vibration that resulted in excessive noise. These couplers have considerably dampened the noise and appear to be strong enough. I haven't done extensive testing so I can't say what the longevity of these will be. I also had a design constraint of no longer than 25mm so the dimensions are 25mm long, 26mm width and height.I printed this from ABS and did not try PLA.I used a .35mm extruder nozzle. I sliced with slic3r 0.8.4 and have included the config.ini file I used for this print. I'm sure someone out there can come up with some better settings but, this should give you a good start. If you do find this useful and come up with any better settings please post it in the comments. I also included the exported .stp file which should be able to import into most 3D programs for modification. It wouldn't be that hard to modify this for different shaft sizes.Just need four M3 screws about 30mm in length and four nuts to go on the end.Also, I used the brim setting for the first layer on the part so you may have to clean up the bottom of the print a little or just set the brim to 0 before you print.July 8th, 2012 - I updated the part so that it should require less cleanup. It should now just be a print and use item now.