magnetic filament measuring wheel

thingiverse

Here is a video of the clipping mechanism https://www.youtube.com/watch?v=QH0irx4wX3k I was tired of using calipers to measure the exact amount of filament extruded which is tricky to do on my printer due to the placement of the rolls so decided to use some random parts I had around for a precision filament measuring device. It is a work in progress so is not complete as of yet. It uses the cheap 4096 positon as5600 rotary sensor that can be found for as little as $2 on ebay and aliexpress. (make sure you get a matching magnet too). A uC then reads the position and reports it over serial to my computer. (though, 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 the vitamin count. The bearings are a plain 604 and a u604zz 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 is hard to get perfect with the existing cap design. this needs reworking or it is too fiddly at the moment. - no public software yet as i am 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.