Robo3D R1 Direct Drive MOD 2019 DOTBIT and TITAN

thingiverse

This mod is designed for three types of extruders: DOTBIT, TITAN, and MK8 metal LEFT. It's a copycat version of the BONDTECH. The DOTBIT requires shaving off some plastic so its bottom is flat. Works with all three extruders. Each one was tested before posting. The files are named after what extruder they are designed for. DOTBIT and TITAN extruders need to have a Nut Holder printed and placed inside the extruder. A hole must be drilled in those extruders to allow the bolt to go through the nut. Everything else is self-explanatory. This mod has several benefits: it lowers the center of gravity, centers the belt and pulleys for less whiplash effect, reduces weight, and gains 10mm print space on X axis. The Post L model with offset was created to achieve this. You can attach any size motor you like, but I use a small 26mm motor from E3D. It works okay so far, but a larger motor will give more torque if needed. A bigger motor or the original 40mm motor can be reused. The extruder is mounted to the carriage using a special designed Nut Holder that fits inside the extruder. This part holds the nut which secures the entire extruder to the carriage with an M4 bolt coming from the bottom of the extruder. This mod uses IDC ribbon cable, 14 wires long. The wiring includes 2 for hotend fan, 2 for cooling fan, 2 for thermistor, 3 for heater (2 positive combined and 1 negative), and 4 for motor. However, you'll need to figure out how to wire the ribbon cable yourself. You can see some pictures of a similar mod I made earlier on Thingiverse: https://www.thingiverse.com/thing:550788. I used this mod for years and it worked great. To assemble this mod, you'll need 2 M4 screws and nuts that fit into the hot end clamp as well as into the extruder itself inside. The Cover or FanFront are used as clamps to hold the ribbon terminal attached to the carriage. If you don't want a fan on the front, just print the Cover to hold the ribbon terminals and print FanBack instead. You can reuse the original smooth rods, but I advise getting new ones along with bearings. April 2020 Rail mounts were updated to allow securing smooth rods inside with screws to prevent buckling as you move the carriage up and down. Move the carriage up and down by hand and observe the Z axis smooth rods. They should not move further or closer to each other. Holes will let you adjust smooth rods position inside the rail mount and secure it. This is not required if the smooth rods are in very tight or cut to size exactly as needed.