Prusa XL Flex / TPU Filament Upgrade

I was unhappy with the various flex/TPU printing options for the Prusa XL, so I made my own and have at least 200 hours printing TPU on this setup with no issues. This solution uses the following parts:

- Attachment Arm, 1 each (printed - model included) - Spool Holder, 1 each (printed - model included) - PTFE Tube, 2 ft (mcmaster.com part number 52335K32) - TPU_Clips.stl, 5 each, from @Bernd (https://www.printables.com/model/718498-prusa-xl-soft-tpu-cable-clip-to-extruder-prusa-xl/files) - PTFE_Extruder_Holder.stl, 1 each, from @Bernd (https://www.printables.com/model/718498-prusa-xl-soft-tpu-cable-clip-to-extruder-prusa-xl/files) - M3x12rT screw, 1 each (Prusa part from printer spares) - M3nEs nut, 1 each (Prusa part from printer spares) Printing and assembly notes:

- The Attachment Arm mounting hole will need slight hollowing out until the screw can fit through it; it was made intentionally narrow to avoid it being too loose. It is printed at 30% infill with supports everywhere with a 10mm brim - see file for specifics. - The arm is made to be able to be tightened with the M4 screwdriver included with the printer and the screw/nut listed in the part list. - The Spool Holder can be scaled larger or smaller as needed for a tight fit on the Attachment Arm, as this could change with filament and printing parameters, but I found the designed size to be optimal for ABS and PETG. Printed at 30% infill - see file for specifics - When attaching the Spool Holder to the Attachment Arm, gel Super Glue may be used if you have loose fitment issues. - The PTFE tube for flex filament is more accessible if the tube is only run from the beginning of the first clip to the end of the last clip as shown in the photos. Take care when cutting it not to crush the ends - The PTFE extruder holder is not needed, but I find it to be a nice spot to park the non-flex tube when I have it disconnected, so I think it's worth printing. - It's important to place the spool as shown, which is upside-down compared to normal, so the filament comes off the bottom. The filament should then be routed up to the right side of Extruder 1 to avoid interference with any other parts. It will very slightly rub on the Extruder 1 mount, but I don't see any issues with this. - The filament sensor must be disabled, or a roll of filament in the normal Extruder 2 position can be inserted to trick the sensor into being happy.