magnetic filament measuring wheel

thingiverse

Here is a video of the clipping mechanism. https://www.youtube.com/watch?v=QH0irx4wX3k I grew tired of using calipers to measure the exact amount of filament extruded, which proved tricky on my printer due to the placement of the rolls. I decided to use some random parts I had on hand for a precision filament measuring device. It's a work in progress so it's not complete yet. The cheap 4096 position AS5600 rotary sensor, available for as little as $2 on eBay and AliExpress, was used. Make sure you get a matching magnet too. A microcontroller then reads the position and reports it over serial to my computer. Adding a cheap LCD screen and making it standalone would be straightforward. A main difference from other such mechanisms is that it can be 'clipped' over existing filament without having to rethread it through, so if you suspect an extruder is having issues you can clip it on the feed line and watch it without having it permanently installed. Or it can be used when measuring out filament by hand. It also uses a flexure instead of a spring to reduce vibration. The bearings are a plain 604 and a U204ZZ that has a U channel. This is not complete and has some issues, it needs more work to be usable. The magnet needs to be exactly parallel to the sensor and that's hard to get perfect with the existing cap design. This needs reworking or it's too fiddly at the moment. No public software yet as I'm using custom firmware and not Arduino, but a search for AS5600 Arduino will turn up lots of sample sketches on reading it. It should have stops to align it with and clamp onto a PTFE tube so you don't have to manually hold it in place.