DD-MK7 – Prusa i3 Direct Drive Extruder

I’ve searched a lot for upgrading my old extruder to a direct drive one. I’ve found lots of nice designs on this website but I wanted to design my own with the following targets :

• Using only parts I had in my spare parts
• Fits Prusa i3 Rework style X-Carriages (M4 23x23mm mounting pattern)
• Idler with adjustable spring tension
• Compact design, quick to print, but still strong.
• Short filament path / As close from the drive gear as possible (Ability to print with flexible materials)
• Compatible with different Hotends (Tested with E3DV6 using a specific spacer, but Hotends with similar groove mount can be fitted easily)*

This project took a lot of time to design, there was a lot of try/fails and I’ve completely redesigned it 3 times. The actual design works really well (More than 150 hours of printing and no issues at all so far). Materials tested : ABS, PLA, PETG and TPU.

*Hotend mount of this extruder uses top and middle groove. Dimensions : 16mm diameter x 6mm (Top groove) / 12mm diameter x 5mm (Middle groove) If you’re planning to use a different Hotend than the E3DV6, you will need to make a custom spacer.