User:Tonyarm/Filament Sensing

Filament Tracking and Sensing

Problem Statement

This page is dedicated to the project of tracking filament to make the printers more "self-aware" in the case of a problem. In this case, the project is designed to make sure that the filament is moving. The occurrence that the filament is not moving is a symptom of possibly several issues and generally occur when the user is not looking at the printer. For this reason, it is beleived that the user should receive some version of a warning whether it is received via pop-up, noise, etc...

Approach

The first practical idea was to use an optical encoder to read whether the filament was moving or not. For those who don't now, an optical encoder is just a wheel with a certain infill pattern that allows some form of EMF (more generally in the form of light or infrared) to pass through or block it. As the wheel would spin the light would go through, then get blocked, then go through, etc... The more of these "spindles" and spaces there were on the wheel, the more precisee the optical encoder was. This setup was used in old analog mice back in the 1990's before they would use lasers (to all of the younger generations: there really was a time where mice did not have lasers and the were not connected via USB) to track the ball in the x and y axes. The spindle-like wheels would be in contact at a point normal to the surface of the ball and would spin in the same direction as the motion of the ball on that axis. This wheel would be in between an infrared light and corresponding sensor. The pattern on this wheel would be radial lines with specified a specified thickness that appeared to be a spindle on the wheel of a bicycle.