May 12, 2025
Description
This is a an attempt to build a simple dualstrusion mechanism, using a single motor and single hot end.
The idea was to provide with a simple upgrade possibility to many people who have a single extrusion setup. And keeping the cost low and fun high while at it!!
Right now i am designing for a direct-drive setup. But this can be easily modified for a Bowden type extrusion setup.
Also for the cooler, I am using an aluminium block with a heat-sink. (custom design) but if you wanted to use a E3D v6, simple modifications could be done.
Assumed limitations:
The setup being designed consists of:
Tips:
PROGRESS
UPDATE: upload of the cam and an updated Servo mount.
UPDATE: As i started print and assembly, i see small things to improve or errors.
just small updated part. Looks promising still.
UPDATE: first dry assembly done without much issues. A few changes done to the arms to allow space for the servo arm. Two small pegs address to the end of the arms to anchor the rubber bands or spring. From the length of the arm and basic calculations it seems this cab be done with a 9gms RC servo!!
To the community do write in... With thoughts to improve the design.
UPDATE: Firmware still an issue. Got Marlin to (sort of) work but the motor keeps going the wrong direction! For the mechanics, there seems to be a problem with creating a sharp enough temp difference in my design, leaving the retracted end of the filament either a blob jamming the mechanism OR a long melt-cone which the MK8 drive misses.Some PTFE tube is in shipping to help solve this!! NEXT OPTION: change the design to give each of the two filaments long enough tunnel so i can live with long melt cones and still work.
UPDATE: firmware -done!! Marlin with modifications.
Hardware- almost done. One filament is not extruding enough. I wonder if there mk8 drive is directional!!!??
UPDATE: a lot of changes. But I have still not given up on the initial idea of making it simple. Retraction during filament change is leaving a thin thread of filament inside the e3d causing it to jam when the next filament comes in. It would be great if someone could point me in the right direction. Wait before retraction? Very fast or slow acceleration values for the E axis?? High extrusion temp?
UPDATE: uploaded the new set of files. Now it would be possible for people to download and test all the parts. Firmware still needs fine tuning. The servo position and Extruder motor direction going out of sync randomly after 3-4mm build height.
License:
Creative Commons — Attribution — Noncommercial
7
bampi2k
