Easy exchange filament extruder

myminifactory

For a new printer, I required an extruder setup. Because I print with ABS frequently, this one was designed specifically for that (though it also works well with other filaments). When printing with ABS, you want to prevent airflow from passing over the printed parts. Therefore, the air is drawn in from above, then passed through the Hot-end and back out at the top. The same airflow design is used for the motor as well, ensuring that the printed part never gets cooled by these two fans. For the dimensions of these snail house fans, please refer to the picture. I also wanted an extruder where changing filament would be easy. On most extruders, you can't see the filament wire, making it difficult to change filament. If you run out of filament during a print job, you're in big trouble. To address this, I designed this one so that you can always see the filament wire. Since I have 3 different sizes of Filament (1.75mm, 2.85mm & 3mm), this extruder can accommodate all of them. To achieve this, I created an exchangeable filament guide. For the 1.75 mm filament, I also need to install a Teflon tube because the Hot-end is designed for 3mm wire (I highly recommend using a Teflon tube as it makes the filament flow much smoother). The filament guide is also adjustable, allowing you to perfectly guide your filament. In the photos, you won't see this guide because it's still a prototype model; on that version, the 3mm guide is fixed to the body. Not very smart, as you can no longer adjust anything – and I broke it anyway! As a loose part, you can simply print it out again. The guide is mounted using a washer, M3 nut, and 10mm bolt. The small filament driver (11mm diameter) is attached to an M8x50mm bolt that I had lying around. On the lathe, I turned the end of this M8 bolt down to 5mm so the driver can be securely mounted on it; please see the pictures for more details. The Hot-end is a cheap Chinese model that I don't even know the name of, but it works very well. For the dimensions of this Hot-end, please refer to the pictures. The stepper motor is a Nema 17 x 47mm. If you plan to use 2.85 & 3mm filament wire, I recommend using a strong motor for this setup. In the picture, you see a 42BYGHW811, but I'm currently using an SL42S247A (which has a bit more torque). As a driver, I still use an A9844 with heavy cooling and a heat sink. For the main body, I had to add support material; please see the picture for information on removing the support material. All other parts can be printed without any additional support. I've printed all the parts in PET-G at 0.2mm resolution using a 0.4 nozzle. You'll also need: * 3x bearing 608z * 1x 11mm driver * 1X M8 x 50mm bolt or something similar * 1x hot-end * 2x snail house fan * 1X spring (optional, depending on the filament material) * 1X nema 17 stepper * 1x kapton tape * 12X M3 nut * 4X M3 x6mm bolt * 9X M3 x10 mm bolt * 3X M3 x20mm bolt * 9X M3 washer (optional) * 1X M3 big washer for filament guide * 8X M4 nut * 5X M4 x20mm bolt * 1X M4 x40mm bolt * 5X M4 washer (optional) After assembly, it's a good idea to apply kapton tape on the bottom to protect the plastic from all the heat. This way, the plastic will last longer.