Looking for ways to make a Filament feed sensor.

Delta printer being what they are, it would be a lot better if we could have a sensor, optical or mechanical, so that we could adjust the extrusion automatically.

Does anybody know of a reliable way to do this?

An Optical mouse sensor is the first thing that comes to mind but it might be too unreliable. there was small discussion here about it, but since the request as been closed we will continue here. Personnally, my own extruder makes marks on the filament, i thought that it might help so that was the reason i was still keeping this as an option...

When looking at the mechanical alternative, i think its a bit scary, the word slipping comes to mind, but ErikZalm says it work perfect, so... There is an example over here: [oaknsilicon.blogspot.ca]

anybody has other ideas?

Edited 1 time(s). Last edit at 06/22/2014 04:22PM by swe3tdave.

I had this idea for mendel extruders, dont´t know if deltabot extruders are any different, since i am lacking deltabot knowledge:

Usually you drive your filament between the hobbed bolt/wheel/whatever-drives-the-filament and a bearing.
The bearing only rotates when filament actually is transported. Bright marks on the bearing can easily be detected as moving with a photodiode/resistor.

sorry for not replying to you sooner, an optoresistor is a device that looks at the quantity of light that reaches it, what makes you think it would be better than an encoder? and did you even read what ErikZalm said? he said that the electronics he tried worked perfectly. so the encoder is the way to go, and he is looking at a good bearing or wheels combo i guess i could say, that correctly convert the linear movement of the filament into rotation the encoder can pick up. the software he said would also be an issue.