Barrel cooling duct for MendelMax 2 & JD Dually Belt Driven Extruder

I was having heat creep issues in my J-Head barrel during dual extrusion that wouldn't be a problem with single extrusion. It is recommended to cool the barrel anyway.

3D printer parts and enhancements

Creative Commons Attribution Share Alike

Commercial use is allowed, you must attribute the creator, you may remix this work and the remixed work should be made available under this license.

Learn more or download attribution tags


I designed this to fight the noted heat creep problem. I also wanted to prevent intake and exhaust turbulence from warping the part, thin profiles are particularly susceptible.

This is designed around the J-Head hot ends, it could work with other hot ends that have a 16mm diameter barrel.

I intended this for use with ABS and other materials where cooling the part would be unwanted. For PLA, you need another fan to cool the part after it is laid down.

Materials and methods

I designed this intending for 0.5mm line width. So a 0.4mm or smaller nozzle is recommended.

You will need to tap the MM2 carriage, I used M4, M5 and M6 taps for the various holes. You will also need some miscellaneous M3, M4, M5, and M6 hardware. I apologize for the eclectic mix of hardware needed, but that's what ended up working given the mount plate in question

All screws I chose are pan head screws, Phillips drive. Others will work.

- 2x M6 x 8mm (or 10mm, 12mm with flat washer) for the rear side mounts
- 1x M5 x 8 for the rear center mount
- 4x M4 x 8mm, 10mm or 12mm long pan head screws for the front side mounts plus to screw the front and rear sections together
-2x M3 x 6mm (or longer, 8 and 10mm will secure the top fan shroud)
-4x M3 x 18mm screws to mount the fan & intake to the rest of the ducts.



Issues are used to track todos, bugs or requests. To get started, you could create an issue.


3827b9da70d70822e973fa17252f92fe?default=blank&size=40JDM published this design ago