Creality Sermoon D1 Z-Sync

This is a variation on “Creality Sermoon-D1 Z-Axis Floating Synchronizing Idler Pulley” by shadowf@x (Thank you shadowf@x for your original idea and inspiration!) that uses 3d printed pulleys instead of ordering metal ones. You should go to shadowf@x's page to download and print the idler according to the instructions there, as well as to give recognition and downlead points. I have printed the pulleys in the orientation shown as well as the other way ("upside down") and either way seems to work fine as long as supports are used and made to be easily removable. It's probably also a good idea to take a hobby knife or something and carefully remove any seams that appear in or on the pulley grooves so the belt runs smoothly. I set the wall loops high and infill to 100%, much like I always do for small round, load-bearing rotational parts, and parts with screw holes. It seems to be working fine so far, and there is no loss in overall build height because the basic drive geometry is not changed by using these. I tapped the clamps on the pulleys with a 3mm tap right into the raw plastic and used M3 x 10mm button heads, being careful not to over torque them. If they prove unreliable over time, I suppose I could use some heat-serts or something, but they seem tight enough as far as I can tell. I used McMaster-Carr #7947K763 for the belt, which is a Gates Powergrip Gt 848-2P-06 848mm long 3mm wide 2mm pitch belt, and being shorter than the one shadowf@x uses, combined with the larger pulley diameters, calls for a much smaller diameter idler pulley, with mine working out best at 90mm, but you may need to adjust this slightly to compensate for variations in printing dimensional accuracy. This potential need for adjusting is also mentioned on shadowf@x's page. Just change the x and y dimensions, leaving z at 12mm. I like the way the printed pulleys came out, but in the future I plan on designing a different idler that is fixed because the floating one still has a little bit of play, like enough to go off by one or to teeth on the z motors if pushed unless it's really tight and I don't like the belt being too tight because I fear that this would put a lot of excess side loading on the motor output shaft bearings which they aren't designed to accomodate, but for now, this setup is doing what it needs to, mainly keeping my z screws in sync whenever the motors are un-energized and I inadvertently bump one end of the build plate.