This sensor (not my casing, that you can print from here!) is now available from Duet3D!
DISCLAIMER: COMPARATIVE TESTING WITH THE REFERENCE DESIGN FROM DUET3D DOES NOT SHOW ANY ADVANTAGE WITH THIS SENSOR HOUSING AND IT IS HARD TO INSERT FILAMENT TROUGH IT. I'll publish a new design soon but for now I do not recomend to print this one :D But it is cute.
First, this approach is a hypothesis! I am not sure about the aperture or if this will help to increase the sampling and speed sensibility!
Known Issues: THERE IS NO WAY TO SEE THE LED :D I would recommend to have the led to the back of the board!!!
I used the datasheet as reference, based at the 1,275 cpi at 1mm. I calculated the size of the pixel based on the 3.5mm of the chip (I know.... the sensor and laser are smaller, etc... but just to make things easier) and calculated the size of the footprint at 30mm. This rendered approximately 120 degrees of aperture.
Using as reference the 9mm distance from the filament and opening the area only to the length of the filament, and a little to the perpendicular, i think it can increase the sensibility and give a better response to fast movements than that very tiny small window of the reference housing. Avoiding scattering of the laser will be achieved by a light sanding of the internal surfaces.
Added 0,2mm for better fit of the board. The old one needed some scraping :D
3 Perimeters. Must be black.