Prusa MK3s External Filament Sensor

Modified version of the external sensor mount that Bondtech made for their BMG upgrade. This version fits the stock MK3S R4, in case you have some issue with the functionality of the sensor and don't want to take the extruder apart. It uses the stock IR sensor, and the spare ball / rare earth magnets from your spares bag. If you don't have these parts, they are all available on Amazon as a kit for around $12.

Printing Tips using PrusaSlicer: Turn on detect thin walls, and use one of the detail Prusa profiles. Put support angle at 5 degrees (so it only supports the ledge). Lastly, click on the pecker arm object, go to add settings -> Layers and Perimieters -> Detect Thin Walls. You want this turned OFF for the pecker arm, but you want it on for the other two objects.

Original: https://github.com/BondtechAB/Bondtech_Prusa_i3/tree/master/CAD-Files/MK3s%20Sensor%20Add-On

The STP file includes a version of the BMG version that is (mostly) unshelled.