Indirect LASER Filament monitor using DUET sensor

thingiverse

Hi everyone! This is my concept design using an indirect laser filament sensor based on the LASER filament sensor from the Duet, taking inspiration from the laser filament monitor for the Duet boards but with an innovative twist - indirect reading. I scoured my Anet A8 for spare parts and incorporated them into this design. Direct reading has proven to be pretty useless when dealing with our typical filament range, as it consistently resulted in fake errors even after adjusting the detection range to 10-150%. In search of a better solution, I experimented with indirect reading concepts from Thingiverse and the Duet forum, utilizing bearings. However, these attempts were not always reliable due to the bearing surface's lack of grip on the filament. This remix of those concepts seems to be working effectively for me, providing constant extrusion readings between 99-131% regardless of which filament I use :). Here is my firmware configuration: M591 D0 P5 C3 R90:160 E5.0 S1 ; Duet3D laser sensor for extruder drive 0, connected to endstop input 3 (E0), tolerance 90 to 160%, 5mm comparison length, enabled Here's my Bill of Materials: - [Laser filament monitor](https://www.filastruder.com/products/duet-filament-sensor) or [clone](https://www.aliexpress.com/item/32958995732.html?spm=a2g0o.productlist.0.0.507a2ad9D08dLk&algo_pvid=bda03b49-ae83-4274-85a5-3d7947571b82&algo_expid=bda03b49-ae83-4274-85a5-3d7947571b82-7&btsid=0ab6d69515899598638465618e9c9a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_) - 5 mm diameter Carbon fiber rod (aluminum or other materials may also work; I haven't tested them yet) - [U604 U groove deep groove ball bearing 4x12x4mm](https://www.aliexpress.com/item/32593507702.html?spm=a2g0o.productlist.0.0.57d6528e7kPXTa&algo_pvid=891ab4ff-23fe-46da-9fd6-7192f18ca1a9&algo_expid=891ab4ff-23fe-46da-9fd6-7192f18ca1a9-5&btsid=0ab6fb8315899599550713742e73c3&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_) - 2 x [MR95ZZ bearing](https://www.aliexpress.com/item/32815201066.html?spm=a2g0o.productlist.0.0.423f3f86R7CXux&algo_pvid=e599ffa7-d854-4ef0-8640-a19ce0d67ccf&algo_expid=e599ffa7-d854-4ef0-8640-a19ce0d67ccf-1&btsid=0ab6fa7115899605660923815e2468&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_) - 2 x M3 L = 20mm screw - 2 x M3 insert brass nut - 2 x M2.5 L = 6mm screw for plastic - 10mm of 1.75mm transparent filament (to see the LED's status from outside)