Support for U20 filament detector

Context:

The support of the filament detector on my Alfawise U20 had been eroded by the filament to the point the filament was no more detected. This lead the printer to stop working. A quick fix was to use an old used detector (on which I made a shortcut so the filament always seem present to the printer), remove the detector with its support and use a iron wire to protect the extruder. All this permit to work a while but isn't satisfying.

The long term fix is to redo the detector's support with a trick to avoid erosion of the new support. The trick I find is to use an M2.5 nut as the entry to avoid plastic to plastic contact and so the erosion of the printed part.

Unmounting and remounting:

To work on the detector's support, you'll need to remove the moving part of the extruder's "wrench" (on which it's fixed) and detach it of the printer. For this there you have to unscrew only one screw !

Space problem:

The new piece is wider than the original. Without the filament inserted it touch the Z-axis's threaded rod but when the filament is inserted it doesn't touch any more this axis.

External hardware:

• 3 M2.5 nuts,
• 2 M2.5 screws (l=10mm max !) to fix the detector (cylindrical head recommended).

Enhancements:

The movement of the filament not only erode the detector's support but it erode even more the detector itself. A good thing would be to add a part between the filament and the detector. This should be possible as, vertically, the space is not as limited as it is horizontally due to the threaded rod of the Z-axis!

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