This mounts on top of the 20X20 extruded aluminum between the 2 motors (extruder1.stl) and between the 2 corner pulley mounts (extruder2.stl). I'm going to suspend the extruder motor about 1ft or so above the carriage assembly to shorten the distance to the hot end as much as possible.
Use 1/2" EMT (electric metallic tubing). I plan on epoxying the tubing in place after a test fit. All the sleeves have a 19mm inside diameter.
I'll add some pictures when I get it all printed and put together.
Added extruder7.stl. & extruder8.stl to mount the filament reel above the extruder.
Added extruderplate.stl, extruderplate2.stl & bowdentubemount.stl for remote reel location instead of overhead. The hole on the left hand side of the extruder plate is for the wires to the hot end, fans, etc... to go through.
Got it put together. The horizontal pipe is 19 3/8" long. I made the vertical pipes about 8" long. I don't see a need to glue it together and the extruder mount moves around a little (rotates on the tubing) when it prints as it needs to. I might glue the vertical pipes into the base to make it less shaky, but its unnecessary. I found using 1 wrap of 3M electrical tape (not the cheap stuff) on the ends of the pipes made a tight fit and eliminated the wobble.
I wound up leaving the filament where it was. It would be too top heavy, but I left the Tee part in case someone wants to use it. I'm impressed with the way it turned out and it allows me to get rid of the cable chain. I need to splice about 16" of wire to make them long enough, but I'm getting rid of that molex connector which has already given me problems with loose connections. So it's a pain but a plus. I used Chinese finger trap "Tech-flex" on the wires & bowden tube. You can leave the wiring as is and just move the E stepper motor wire if you don't want to tackle such a project.
After you get it put together pull back on the top of the extruder plate and drop in a little CA glue on the corners to keep it from flexing on retracts.
Extruderplate2.stl mounts on top of the carriage.
Bowdentubemount 3 & 3A is for the reel mounted in the open. 4 & 4A is for use with a dry box.