Just a little thing I whipped up because I wanted my filament spool mounted low (like this one or this one) but the filament feed path over the top bar because of feeding a direct drive extruder.

It would get in the way of wiring, spool didn't unwind nicely, etc, and it bothered me enough to spend half an hour on a design. Maybe you have a use for it too.

It was designed for the spool holder of the Ender3 series printers with a spool holder mount on the lower parts of the frame. Will probably fit other printers too if they have a 2020 extrusion top bar and a low mounted spool holder.

I included STL's for both parts as well as a combined one.

Needed materials:

• A bit of filament for printing, obviously. I used cheap recycled PLA, it's strong enough.
• 2 pcs PC4-M6 connectors (small bowdentube fittings, like the ones on most bowden exruders)
• A length of 4x2mm PTFE/Teflon/Capricorn tube (aka bowden tube)
• 2 sets: M4x8 bolt, M4 nut and (optionally) M4 washer
• 2 pcs M4 T-nuts
• 2 pcs M4x8 bolts

Instructions:

• Screw the PC4-M6 fittings into the two printed parts
• Attach long stick guide onto the spool holder with the M4x8 bolts/nuts
• Attach the small guide onto the top of the printer frame with T-nuts and M4x8 bolts
• Cut a piece of PTFE tube to length and attach to the PC4-M6 fittings on the two guide parts
• Thread filament through the PTFE tube to your Direct Drive extruder