Entry-FS-Case tapered path remix for XL

Update April 18, 2026: I found that the original remix cannot reliably hold the M6 fittings over a long period of time because the threads on the fittings are so short.  The new remix used Ruthex short M6 heat inserts to hold the M6 fittings.  This in turn required one more change --  a bushing should be used on the output side of the Entry-FS-Case to ensure the filament doesn't get stuck between the back of the heat insert and the fitting itself.  In the picture below,  heat inserts are shown in yellow,  and the bushing in orange. M6 pneumatic fittings are not shown. Filament enters on the left. 

The bushing is inserted with a T15 wrench. The torx drive doesn't print really well, but it's good enough.  With the bushing on your workbench, torx drive up, push/force the torx wrench into the slot, then drive into the heat insert like shown in the picture above. 

Original text: 

[The filament sensors in the photos are hanging at an angle because I've moved them up to the horizontal extrusion, but the wire isn't quite long enough for them to sit straight.  Moving them to the horizontal extrusions makes space for the filament dryers sitting on side tables:  https://www.printables.com/model/1585097-original-prusa-xl-side-tables]

I just finished a project to reduce the friction in the XL filament paths by swapping PTFE tubing to larger diameter, and moving from spring to magnetic side filament sensors.  tg73's remix of the side filament sensor was my inspiration, but I wanted a bit more.  My remix incorporates the following improvements:

• Filament paths through the filament sensor case are tapered to keep the filament centered.

• Magnets are inserted from the inside of the case.  The case is 2mm thicker so that the magnets are not visible from outside.

• The left side filament sensor case has the option of adding a M5 heat insert to more securely hold the calibration tool.

• Input and output sides have M6 threads to use with M6-PC4 or M6-PC5 pneumatic tubing connectors.  Regarding the M6-PC5 connectors, I suggest you drill them out to 3mm, to match the ID of the PTFE tubing.  

Here's the factory design (filament travels left-to-right), note the obstacle to filament loading easily:

Here's the tapered version I designed, you can also see where the 3mm magnets are inserted:

Assembly:  I used 3mm diameter magnets (sold as 6mm long, actually closer to 5mm).  Magnets are inserted from the top; be sure polarity attracts the steel balls.  The holes for the magnets are slightly undersized, so the magnets will stay in place.

On the left side filament sensor, you can insert a M5 heat insert to better retain the calibration tool.  I used the CNC kitchen tool https://cnckitchen.store/products/ts100-101-adapter-tips-set-m2-x-m3-m4-m5-m6-1-4-m8-100-lead-and-cadmium-free which easily fits through the hole in the bottom of the case.  Otherwise you can rely on gravity to hold the calibration tool like you've been doing all along.

No special printing notes.