K8200/3DRAG CoreXY mod

thingiverse

This is not a project for the timid, it requires almost complete disassembly of the printer's base frame. A lot of swearing and frustration can be expected, but I'm very pleased with how it turned out. I've marked it as a work in progress since I plan to modify some things to better fit readily available hardware and come up with a bill of materials and proper assembly sequence eventually. If someone is brave enough to give it a try, here's the sources - go ahead and take a shot! Here it is printing its own endstop brackets: https://youtu.be/2o1mKZOJG_4 I'm intentionally only publishing the SCAD files because you really need to know what you're doing before tackling this. I've set up Marlin to be in CoreYX mode (notice the exact spelling) and unless you use a recent release from the GIT repository, it just won't home properly. When testing movement, leave the grub screws off the pinions until you're sure the motors are spinning in the right direction and the correct endstops are read. The pinions and idlers are from Anycubic, 16 teeth size which help improve both torque and resolution, and they fit over M3x30 bolts. I have some very tiny washers from my "PC bolts box" that allow them to spin freely, but it's probably possible to make something equivalent by thinly slicing 3mm inner diameter PTFE tubing. I'm using Marlin 1.1.6 from the GIT repository, here are the main changes in configuration.h related to this mod: `#define COREYX // (uncomment this, note, YX, not XY)` `#define DEFAULT_AXIS_STEPS_PER_UNIT { 100, 100, 2560, 640 } // (using the standard M8 allthread rod, and E steps should be tweaked)` `//(Note, I am using TMC2100 drivers, so the axes are ALL inverted compared to the stock drivers)` `#define INVERT_X_DIR true` `#define INVERT_Y_DIR true` `#define INVERT_Z_DIR true`