Rigidbot CoreXY v2

thingiverse

Rigidbot CoreXY v2. This is a conversion of the moving bed Rigidbot printer to a CoreXY machine using 10mm carbon rods and bushings for the X axis.  Version 1 is published here. Please read the instructions and parts list at https://www.thingiverse.com/thing:3468731. The differences between this version and Version 1 include the option to replace the X 8mm steel rod and bearings with a 10mm roll-wrapped carbon fiber rod and brass bushings. Brass Bushings: The bushings are quite cheap, copper-plated steel, but have a thin graphite lining, which provides a smooth gliding surface. The graphite will wear out over time, but doesn't damage or scar the carbon fiber rods. They've been working well for six months of use and I intend to periodically replace them (maybe after a year). Measured backlash in X axis is about 0.05 mm. Adding a drop of *Superlube Precision Oil with PTFE* helps reduce friction. Carbon Fiber Rods: The CF rods should be roll-wrapped and can be bought from eBay or Aliexpress. The rod's diameter usually varies over its length, so it needs to be carefully sanded down to precise fit. This is the most tedious part of the build. See a helpful video on YouTube that shows how to do this - youtube watch?v=0Pg-L1pQ6qU (but sand them wet; carbon dust is poisonous). Igus Bushings: I tried 10mm Igus bushings on the CF rods, but the backlash on X axis was more than 0.15 mm. Polymer bushings work when the machine is quite stiff and perfectly aligned. Idlers and Pulleys: Use only Gates. Minor eccentricity in cheap idlers adds up and shows as wobble in XY joiner and carriage. I found hardware bought at this store https://mellow.aliexpress.com/store/1531088 to be of good quality.