Geared Extruder

myminifactory

Geared Extruder I designed a new extruder for my printer that I converted to a "bowden setup." My goal was to create a simple, strong, and reliable design that would press the filament against the driver gear with immense force. The extruder features an adjustable guide to direct the filament. For now, I retained the gland nut but included parts that can be adjusted for regular Teflon tube holders. On my printer, which is featured in the pictures, the gland nut works exceptionally well. This setup has successfully printed a 20-hour test print. However, on another printer of mine, the gland nut does not perform as well due to its higher printing speeds (60mm/s and above). I discovered that applying Kapton tape to the tube greatly improves the gland nut's performance. I am still experimenting with other tube holder methods. The small filament driver, measuring 11mm in diameter, is mounted on an M8x50mm bolt that I had available. On my lathe, I machined the end of this M8 bolt down to 5mm to accommodate the driver. Please refer to the pictures for further details. The model is designed specifically for 1.75mm filament. For 2.85mm and 3mm filaments, you will need to drill out the holes to the correct size. The gear ratio consists of a small gear with 10 teeth and a larger gear with 43 teeth. If you have any questions or concerns, feel free to ask. Teflon Tube Holder Upgrade FEB-22-2018 This upgrade focuses on replacing the gland nut with tube holder clips. Please refer to the pictures for more information. During my experimentation with these clips, I realized that the diameter of the hole where the clip is placed plays a crucial role in its performance. Since not all Teflon tubes are identical in size, this hole can vary accordingly. My Teflon tubing measures between 3-4mm in diameter. Therefore, I recommend boring out the hole to 6.5mm for optimal results. If this proves too tight, try increasing the diameter to 6.5mm and adjust as needed. April 8, 2018 Spring Update Following my successful use of this extruder without a spring, I encountered issues with a specific filament that was not evenly rounded in its length. This resulted in extruder failures due to the filament bar's inability to flex with the filament. When it reached a section of the filament that was slightly thinner, the filament would slip off the driver gear. To rectify this issue, I incorporated a spring into the design. Although I know this should have been done initially, I opted for simplicity at the time. Now, I understand that a spring makes the extruder more reliable and less dependent on precise pressure adjustments. Please review the additional pictures for further information. * The new pressure bar holder is longer to accommodate the spring. * A new knob, M5 bolt, and 8mm x 20mm spring have been added (note: the old bolt was an M6, but it took up too much space). * The pressure bar has been modified to accommodate the spring.