An Ongoing development of an inexpensive, custom desktop dual extrusion printer.
This is a passion project that had a great role in allowing me to push the possibilities of desktop 3D printing and showcase the capability that can be had in a low-cost 3D printer. This printer has been through many many different iterations and is a project that is never fully finished, rather a working platform to test advancements in low cost custom 3D printing.
THE BUILD
I started this build almost four years ago now, where I wanted to have a more capable machine that would be able to do a lot of different types of 3D printing housed in a budget frame. Therefore I started with the frame of the most popular budget printer, the Ender 3. From here came a plethora of upgrades to allow for dual extrusion printing.
Upgrades:
New Mainboard: SKR 1.4 Turbo
New Hotend: Triangle Lab’s Chimera Clone (2 in 2 out)
BLTouch (genuine)
New fan shroud
New mounts for extra extruder steppers
New Firmware
These parts built the first generation of my dual axis machine as seen below:
Notice how this printer doesn’t have a purge block or prime tower, two aspects of normal dual extrusion that make it very resource consuming, on both time and materials. The goal for this machine was for a setup that was so dialed in that neither of those things was needed.
Here I am using a Petsfang style mount for the hotend with a remixed fan mount to have enough cooling capacity to cover both extruders. Coupled with a long bowden tube that had the extruders mounted at the top of the frame, this setup worked pretty well: it was an all metal hotend so it could easily handle higher temp materials, and it had very few problems with oozing and retraction, even with the bowden setup.
However, I wanted to print flexibles, specifically, I wanted to print 85A TPE, something not possible with a bowden setup. Therefore a direct drive extrusion, where the stepper motor is as close to the hotend as possible, was necessary. Yet this created quite a large packaging problem – I had to fit two 5015 blower fans, two full size extruders, a BLTouch, and the hotend, all with the determination of not losing any buildspace. Furthermore, I came to a weight problem. All of this was heavy. From there, I realized that not only did I need to redesign the whole entire hotend, but also upgrade yet again with a dual z-axis setup that would be able to handle the weight. I looked to see if anyone had done this sort of setup online, and while I found some inspiration, I couldn’t find anything that perfectly fit my needs, so I set out designing it by myself. I came up with the design you see below. It is definitely very cramped, and admittedly a bit of a hassle to disassemble, but it worked surprisingly well. After reworking the code on the new 2.0.x branch of Marlin, I was off to the races again… until there was a third iteration.
While the dual direct drive extrusion was a fun journey, and honestly the version of this printer that I liked that best, it seemed that it was time for a practical change. I found, as the printer got older, that I wasn’t really using that extra temperature of the all-metal hotend as often as I thought I would, and having heat creep made it difficult to tune retraction sometimes. So, although this might sound a bit counterintuitive, for the sake of reliability, I changed it to a PTFE setup. even with PTFE, I find that I can still print PLA, PETG, TPU, and ASA very well, which is more than suitable for me, while I can let my printer that specializes in exotics handle the rest. I found that this made the printer much easier to tune as far as retraction and oozing went, and overall, surprisingly, a better machine to use.
If you are interested in building a custom dual extrusion 3D printer, feel free to reach out to me, I would love to talk to you about it!