PrintrBot Plus 2.1 Dual Alu Extruder

youmagine

These parts provide a means of mounting two PrintrBot Alu direct drive extruders on a PrintrBot Plus version 2.1 (1311) printer, although they may work with older models. They will not function properly on any Plus with the X-Z upgrade; I plan to perform this upgrade in the future and then create a modified version of these parts for use with an upgraded printer. There are plenty of 40 mm fan mounting places available for cooling purposes: two to cool the motor at the back, two to cool the alu extruder components, two to cool the ubis extruder, and two to cool the print job. While you may not need most of these fans, the holes are there for your use. The design includes slots to hold M3 nuts for some fan mounts, making it easier for you to assemble the parts. I have chosen to use 40 mm fans instead of a single 80 mm fan to keep the weight down. The little raised slots around the edges are designed to hold zip-ties, which will help keep wires organized and tidy. Installing these parts on your PrintrBot Plus version 2.1 printer will reduce its X-axis movement by approximately 20 mm due to increased width. You must adjust your printer's max movement setting to around 180 mm for the X-axis. The extruder offset is 37 mm along the X-axis, meaning that one extruder is located 37 mm from the center of the other extruder. The distance between the extruders and the 'support wall' along the Y-axis is 17.45 mm. When I refer to the 'support wall', I am talking about the vertical wall behind the extruders where you mount the linear bearing sleeves. As a reference point, the center of the original wood-based extruder is located 15.76 mm from the same wall, and the center of the PrintrBot-designed single Alu extruder is 17.4 mm away. You may want to slow down your printer with all this installed due to increased weight and potential instability. I have been able to print at speeds of up to 75 mm/s without issue, but I do not see a need to go any faster. I always print my printer parts out of ABS because I don't have access to more exotic filaments like nylon. The infill is usually set around 50% or higher when printing with ABS. When using this system, PLA may not be suitable due to the high temperatures generated by the motors and hot end. To mount the ExtrudrBoard next to the PrintrBoard within the boxed area at the bottom of the printer, I used four M3 15mm nylon stand-offs. There should already be existing holes for this purpose, but I only used two of them as the other two would interfere with the y-axis belt system. The additional two stand-offs were used to maintain strength and facilitate plugging cables into the board. You may need to re-flash your Printrboard's firmware for it to function properly with this setup. My printer was initially flashed with firmware set for three extruders, which resulted in Min Temp errors when I plugged in the ExtrudrBoard. To resolve this issue, I reflashed the firmware to set it up for two extruders. I have included the pre-configured .hex file for the PrintrBoard firmware, which is set with a max X-Axis of 183 and configured for dual Extruders. The PID settings are also included and may need to be adjusted based on your specific setup. I use M8 threaded rods for my Z-Axis, so the Z-Axis steps may not be accurate for you. I have included the SketchUp file for anyone who wants to modify this design to suit their needs.