Filament Guide/Sensor for Anet A8

thingiverse

**Update:** (29 Mar 18) I mounted the sensor shown in the photos this morning. It was a tight fit on the frame, but it worked fine. However, pulling filament through it when the extruder was at one end of the carriage or the other didn't go so smoothly. The sensor really needs filament to pass straight through, with no bends nearby. A redesigned frame that holds the sensor higher and a smaller filament guide underneath that constrains lateral movement near the sensor is likely in order. I started by modifying an existing sensor design and adding a small filament cleaner on the input side along with an attachment point for a brace to hold it to my printer. To figure out the size to make the attachment point after I had printed the frame, I knocked together a simple filament guide that also fits the frame; even at 0.1 mm, it prints in just a few minutes so that I could tweak the size and reprint until I got the fit I wanted from it. Even if you don't care about the low-filament sensor, the guide-and-frame combo is an improvement over existing designs I've run across in that it's bolted to the frame and doesn't slide around. The frame was printed at 0.2 mm with supports that need to be removed carefully. The other components are printed at 0.1 mm. If the frame is also printed at 0.1 mm, the filament-guide and sensor attachment points might be a bit oversized; the attachment point on the sensor has a hole for one of the setscrews left over from building the printer (will probably need to drill it out some more), or you could tweak sensor.scad to shrink the hole to match. A8-0011.stl is included from https://www.thingiverse.com/thing:2288314 for reference purposes, but I found that the upper display mounting holes on my printer were higher than indicated and had to change my design accordingly.