Uconduit - Hot End Extruder Mount

thingiverse

This is another alternative of an extruder mount for the U-conduit printer which uses a Metal J-head hot end. When I designed the Uconduit H-bot printer, I encountered some problems with extruder nozzle wobble. By spacing the X-axis rods farther apart, and using two linear bearings on the top 8 mm polished rod, I was able to minimize the extruder nozzle side-to-side wobble. To cool the extruder hot end cooling fins, a fan was mounted on the back between the two X-axis rods. This air blows through the extruder hot end mounting bracket from the back to the front. There is a short offset duct to get the air down to those heat exchanger fins on the front side. The printed part cooling was accomplished by using a front-mounted fan pointing down towards the extruder nozzle tip. Nut slots were used extensively to create the thread for the bolts (6-32 nuts) and the tubing fitting (10 mm nut). For pictures of the complete Uconduit 3d printer remix, see the link: http://www.thingiverse.com/thing:2176514 Metal J-head V6 hot end link: https://www.amazon.com/RepRap-Champion-Printer-Filament-Extruder/dp/B01GD9054C/ref=sr_1_10?ie=UTF8&qid=1490305106&sr=8-10&keywords=jhead+v6 Print Settings: Printer: Migbot i3 Rafts: No Supports: Yes Resolution: 0.2 Infill: 50% Notes: Because the bearings stuck out on the back, and the extruder mounting surface on the front was not completely flat, the printing of the extruder mounting bracket required support material. This is the only part printed that required support material. I laid the mount on the back three bearing mounts and let the support material build up to the back of the mount and to the inside of the cooling fan duct. That left the very front of the extruder mount completely flat where the top and bottom covers bolt on. The top cover was laid on its back to print (H side up). The bottom cover was laid on its front to print. Post-Printing: Installing Linear Bearings, Checking Alignment, & Assembly After the main body was printed and support material was removed, I custom filed the three holes for the LM8UU bearings. This was done partly to make them a semi-friction fit, and also for the proper alignment of the two top bearings on the rod. Bearings were pushed in by hand and the 8 mm polished rod was inserted to check alignment. Assembly: 1). All 6-32 nuts were pushed into the nut slot and aligned with the appropriate hole. 2). The 10 mm nut was inserted into the top cover plate. 3). The PFTE tubing fitting was tightened into the 10 mm nut in that top cover plate. 4). The top cover was bolted onto the extruder mounting with (4) 6-32 machine screws. 5). The extruder was slid into the mounting bracket from the bottom. 6). The PFTE tubing was pushed through the tubing fitting on the top cover plate all the way down through the 4 mm hole in the top cover, and into the tapered section at the very top of the extruder hot end. Verify that the PFTE tubing is setting all the way into the bottom of the tapered section on the hot end. 7). The bottom cover plate was slid over the hot end top grooves, and bolted onto the extruder mounting plate with (4) 6-32 machine screws. 8). Extruder 40 mm fan was mounted on the back of the Extruder mounting plate with (4) 6-32 machine screws. 9). Front part cooling fan bracket was bolted to the sides of the extruder mounting plate with (2) 6-32 machine screws. 10). The front 40 mm part cooling fan mount and fan were bolted to the fan bracket. with 6-32 machine screws. 11). Entire Assembly was slid onto the 8 mm polished X-axis rods. 12). X-Axis rods were inserted into the new wide X-axis rod end mounts. 13). X-axis rod end mounts were installed on the Y-axis 8 mm rods. How I Designed This Concept I knew I wanted to make the X-axis rods farther apart to stiffen up the hot end mounting. My first design had fans hang off of both sides. I figured that if the rods were to be spaced father apart, then the hot end mount could also be the fan mount. This made the extruder design more compact. The rod spacing was determined by how much room was necessary on the back to directly mount the fan between those rods. Because the X-axis rod spacing was changed, the X-axis rod end mounts to the Y-axis rods also had to be modified.