Triple leadscrew belt driven bed for Hypercube

thingiverse

**Update 2: 22-12-18** I've been trying to fix the z-wobble issue by adding a 10mm linear shaft to each leadscrew, but it didn't work. I'm now going back to my previous attempt, a belt-driven bed. This design is for anyone who wants to experiment with this setup. **Update 1: A New Design** The current design has a weakness - the leadscrews are relied upon to keep the build platform steady in the xy plane, which they're not meant for. To address this, I'm incorporating three 10mm linear shafts into the new design. **The Goal** I wanted to completely eliminate z-banding/noise caused by stiction in the lineair bearings/bushings on the z-axis guides. I achieved this by improving rigidity in the z-direction with a belt-driven triple leadscrew build platform. **Results** The end result is an absolutely rock-solid build platform with no give whatsoever. You also get about 220mm of build height out of this configuration. **Costs** This conversion requires about $15 in parts, plus the printed parts. **How to Do This?** The frame needs to be modified to accommodate the new triple leadscrew setup because the leadscrews need to be secured at both ends. The distance between the top and bottom extrusions of the frame needs to be 30cm for this purpose. This leaves no room for the coreXY part of the printer, so that has to be moved above the top 2020 extrusions. If the CoreXY part remained in the same orientation as in the stock hypercube, the nozzle wouldn't be able to reach the print bed. So all the CoreXY parts (belt idlers, left/right motor brackets, and shaft clamps) have to be flipped upside down. The original hypercube was designed in such a way that if the CoreXY parts butted up against the top 2020 extrusion they would be aligned correctly. To achieve the correct alignment with the flipped CoreXY assembly, whilst still having enough room for the XY joiners to move along the shaft, there needs to be 17.9mm between the top 2020 extrusion and the CoreXY assembly. I've made a simple spacer for this purpose. To couple the three leadscrews, I've spliced my own looped belt by cutting away teeth from one side and material from the other and fusing them with CA superglue. You can buy a looped belt if you don't want to do this. The build platform is attached to the leadscrews via two parts: t8 adapter & bed to t8. These parts are separate to allow for precise alignment of the build platform to the leadscrews and frame before fusing both parts together with CA glue. **BOM** - Two additional t8x8mm leadscrews (or three t8x2 leadscrews for more accuracy) - One gt2 belt idler - One small looped belt to connect the z-stepper to a leadscrew. - Five 20-tooth gt2 pulleys - One 30cm 2020 extrusion (for the build platform) - A small scrap piece of 2020 extrusion to connect the belt tightener to (8cm in my case) - Six KFL08 bearings - A 100cm to 110cm looped belt or 130cm of belt to splice yourself **Please Share if You Make a Leadscrew Driven Platform Yourself!** Don't forget to reverse all motor directions in Marlin since all motors are upside down from the original configuration.