3D-Proto CoreXY 3Z Axis - more stable bed

thingiverse

The original bed mount of the 3D-Proto CoreXY causes the bed to bend excessively. Probing it with a precision piezo yields unstable results on the bed's corners. One side of the bed is now stabilized by utilizing two Z axes, resulting in three Z axes in total. This leads to an extremely stable bed. To achieve this modification, you will need to obtain certain parts: get one additional M8 rod & nut & coupler, acquire a Nema 17 stepper, and secure some additional 2020 profile pieces or other suitable components for mounting the Nema holder on the single motor side (blue parts in the screenshot). Additionally, print an extra Nema 17 holder from Thingiverse: 3183194. You will also need to print two copies of Bed-Z_10mm.stl (buy M5 screws with a length of at least 35mm and nuts) - there are two versions available for 12mm thick wooden panels and one for 10mm, so choose the correct version based on your panel thickness. Furthermore, print two each of Smooth-Z.stl and Smooth-Z_top.stl, as well as two copies of 20x20SockelM5.stl. Lastly, purchase additional sliding blocks and screws to secure everything to the frame. I printed all parts with a 70% infill density without support structures. For the single motor side, I utilized a spare 2020 aluminum piece from the spool holder, as I have already printed the "Filler" accessory from Thingiverse: 3020026. On the two Z motor sides, I rotated the 2020 aluminum profile by 90 degrees to mount the Nema holders. Each Bed-Z.stl component was securely attached to the bed with two screws and nuts. The two Z axes are driven by a dual Z connection on the controller board (Duet WiFi), while the one Z axis utilizes the E1 connection. In the future, I plan to implement a belt system that will enable me to use only one Z motor for all three Z axes, inspired by this design: 2651649. This will free up the E1 connection for a dual extruder setup.