Formbot/Vivedino T-Rex 3.0 BMG and Dragon Hotend Upgrade

thingiverse

This is a straightforward upgrade package designed to seamlessly integrate with the Bondtech BMG and Dragon hotend. 1. Swap out the top two motor screws securing the PCB's with longer 35 mm M3 bolts for added stability, reusing the stock mount screws for the motor and fan mount in the process. Ensure that the fan mount holes are positioned at the bottom of the mount bar once bolted onto the motor mount. Include a 6mm spacer on the Dragon hotend. 2. Fabricate fan ducts using high-temperature filaments like PETG, PLA+, or NylonX, and incorporate supports during printing. When utilizing Cura, opt for tree supports. Use robust filament with 100% infill for the motor mount to guarantee strength. 3. Prior to initiating a print, ensure that you update the E steps by loading the included G code onto an SD card. The upgrade is instantaneous and can be easily implemented. To avoid complications, pair a right-hand (standard) BMG with the left extruder and a left-hand (mirrored) BMG with the right extruder. You may either reverse the motor directions in Marlin or rotate the connectors to achieve this; however, updating the firmware is recommended for simplicity. 4. When building the mesh for bed leveling, detach the extruder thumb screws to prevent the probing extruder from colliding with the right extruder. Maintain a distance of at least 40-50 mm between the extruders and adjust the print bed size by reducing it in the y-direction by approximately 10-15 mm and in the x-direction by about 40 mm to ensure a smooth operation. 5. After the upgrade, you might need to fine-tune your flow rate and other extrusion settings for optimal performance.