Better Tensioner / Pulley / Idler Wheel for Geeetech (pics to prove it)!

thingiverse

[SEE BELOW FOR UPDATES] After chasing down the reason for Y/X layer issues on a Geeetech Pro B/C 3D printer, I realized Z wobble was only half the battle! The wrong/inappropriate idler wheel is another issue! Possibly more of contributing factor to x/y layer inconsistencies than Z wobble. Just picture that smooth wheel as the toothed belt comes across it... a tooth touches it... a tiny force is applied... next is a gap... it goes back down... then another tooth... back up... back down... back up... and so on... and so on... I'm not taking credit for the realization, I know see that many have figured this out before me! Including @TNS whose Anet solution to this problem is what I based mine on for the Geeetech printer. Since I never found a totally ideal solution; a toothed wheel that a) printed well, b) was just the right match for the stepper gear pulley (20 tooth, ~12mm wide at the teeth) and c) I wanted it to use bearings so it didn't fail after a few prints. So between the excellent gear customizer on here and some simple modeling in TinkerCAD, I came up with what I believe is a good solution. I have pics to show that it did indeed improve my print quality, and by quite a margin I must say! I hope the pics do it justice! It's not a perfect, and I tried to highlight the layer imperfection especially in the pics, so when it isn't lit that way intentionally the prints look amazing! So much more uniform, even and smooth, with far less surface 'noise'. An occasional slightly over/under extruded line still, but what an improvement! It also didn't effect my calibration at all, as you can see in the pics the printer still produces a fairly accurate 20mm cube! I don't know if it's 100% because of the teeth, or if the spacers help too (less play in the whole thing... but I'm amazed at how much better my prints look with this! I hope it helps some other people too! I've only tested on my own Geeetech Pro C, but it should work on some other printers (definitely the Pro B, maybe i3X...). Leave a comment if you use it on something else and I'll list it here as compatible! UPDATE: after a few days of printing I had one pulley wheel fail. The side support was warped from my cooler not really getting air to the back when I had printed it, so the flaw allowed the belt ride up. Really, I was too conservative with those side supports anyways, so I used customizer and made a new one (v2) with much beefier sides! I'm still using an original (v1) pulley wheel on Y just to see how it holds up. I have a feeling it's not a design flaw, but just a print flaw. The new one should print well even with inadequate cooling (i.e. a stock Geeetech setup)! It also fits in the holder a better too, since it's a little wider (2mm wider than v1), but it's still a bit (~0.5mm) thinner than the metal pulley wheel, so fit won't be an issue. I had originally wanted to keep it smaller so would be compatible with more holders and to allow space for it to center itself, but I think we need the added strength. If I hadn't been there to stop the print it might have ruined my GT-2 belt, and I don't want anyone's GT-2 belt on my conscience... ---- Customized version of http://www.thingiverse.com/thing:2138421 Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=2138421