Sapphire Plus Z Belt Drive

thingiverse

Sapphire Plus belted Z drive conversion. Z screws got you banding? Frustrated because you are getting print artifacts? Sapphire Plus belted Z drive conversion. Z screws got you banding? Frustrated because you are getting print artifacts? This mod will address issues related to Z positioning. You will need: QTY:8 F608ZZ bearings QTY:2 8,, I,D, washers, 1mm thick - these go in between the 80T gear and bearing QTY:4 8mm diameter hardened shaft (Can cut old lead screw or order 8mm precision rod. Length total to make all 4: approx:190mm. Grind flats on shaft for set screws. QTY:4 GT2 timing pulley: 8mm bore, 20T, 10mm wide for GT2 10mm belt QTY:2 GT2 timing belt 200mm or 188mm. 188mm belt can only use 16T motor pulley. Use a quality belt! QTY:2 GT2 16T pulley, 6mm wide, 5mm bore. QTY:4 8mm bore locking collar to hold the shafts in place or use additional GT2 8mm bore pulleys or cut some motor couplers in half QTY:2 GT2 pulley 8mm bore, 6mm wide, 80 tooth QTY:16 3mm I.D. 1mm wide washers - these are for the lower geardrive mounts + the 4 motor bolts. QTY:6 3mm T nuts for the upper mount QTY:1 approx 1.8m GT2- 10mm wide belt - make sure to get a quality belt QTY:2 3mm threaded insert - this goes into the lower tension block. Once inserted, screw a bolt in and cut the head off. The tension bolt will press against it to move the block. QTY:2 3mm hex nut - this goes into the tension block housing. Tensioner QTY: 10 3mm 20mm long socket cap bolt QTY: 2 3mm 12mm long socket cap bolt Gearbox mount QTY: 8 3mm 16mm long socket cap bolt QTY: 4 3mm 10mm long socket cap bolt Upper mount: One side uses OEM 5mm bolt QTY: 2 3mm 12mm long socket cap bolt QTY: 4 3mm 9mm long socket cap bolt (I believe 8mm long will work) above QTY is for both sides. The bottom case of the sapphire plus is weak and will flex. So when installing the bottom gear drive you may need to shim the 80T pulley side to put a little tilt in the gearbox. When the belt is tight it will pull the gearbox pulley upwards and put a slight tilt in it. I used .015" feeler gauge under the base of the gearbox mount. Install feeler gauge, tighten, move bed up and down to see how the belt rides on the pulley. Adjust, check again so the belt rides in the center. If the belt runs up against the flange too much, it can damage the belt. Make sure the lower gearbox has a good amount of tension or the bed may free fall. Use just enough tension so the bed barely falls. The tensioner has not been tested, so try it and see what issues you may have and report in the comments. I will try it soon and if I change the design I will update the files. I have included the fixed position tensionsers I use now. I had made some tensioners awhile back for another project and ended up printing them in PETG as they seemed to hold better. .STL file included for gearbox template *Special note: The Z motors on the sapphire have short shafts. They will work, but it is preferred to use motors with a longer shaft. **Special note #2: It is advised to use 16T drive pulley on the motor. However, you can use 20T pulley instead. This will require a 200mmm drive belt. Changing to a 20T will make the reduction 4:1 instead of 5:1 and the bed may fall. I have a MIC-6 cast aluminum plate with magnetic 3M and spring steel w/PEI and silicone heater. My bed weighs a lot in total. Maybe with stock setup you can use 4:1. It would be better for the belt with a larger drive pulley. Try at your own risk! I will be changing the lower gearbox to allow 20T pulley with 188mm belt in the near future. The main hurdle in assembly will be the alignment of the lower gearbox. Use common sense! Use calipers to measure the belt distance to the upright of the Z rail 20x40 extrusion at the top and bottom. Take your time! Steps per MM will be 400 with a 5:1 ratio or 8 rotation distance in Klipper. ******UPDATE****** I made a longer tension housing so the belt length is not so critical when assembling. The quality of the 80T gear and GT2 10mm pulleys are very important! Get a good brand that is concentric! *******UPDATE #2***** The bottom frame is not very rigid and the motor plate will flex when the drive is running. I have added a bearing block to support the shaft of the drive. This seems to have eliminated the flex in the bottom plate. The shaft length is 130mm for the drive assembly (8mm O.D. shaft).