Dual extrusion systems for 3D printers have been around for quite a few years, but the additional cost, complexity, and hassle of printing with them have kept them off the workbenches of most hackers. [Jón Schone] from Proper Printing has now thrown his own hat in the ring, with a custom dual extrusion rocker system that can swap extruders without any additional actuators.
The two extruders are mounted on a spring-loaded rocker mechanism, which holds the inactive extruder up and away from the printing surface. Extruders are swapped by moving the carriage to either end of the x-axis, where the v-wheel rolls a ramp and pops the rocker over, putting the new extruder in the center line of the carriage. There are 3 wheels at the top of the carriage, but only two are in contact with the rail at any time. While this system is more complex than simply mounting two extruders side-by-side, it reduces the chances of the inactive nozzle oozing onto the parts or scraping across the surface. The height of each extruder can be adjusted with a screw, and any horizontal offset between the nozzles is checked with a calibration procedure and corrected in the firmware. See the full video after the break.
It takes the Ender 3 gantry and tilts it sideways on a pair of 3D printed supports, and replaces the stock Y azis with a belt on rollers driven by a larger motor through a timing belt drive. He has a variety of suggestions for sourcing a belt, and in his case he’s chosen one from PowerBelt3D. As well as the GitHub repository already linked, it can also be found on Thingiverse.
It’s clear that hacking apart a reliable printer in this way is not for the faint-hearted, and that a cautious hacker might prefer to wait a while for a cheaper off-the-shelf model. But we can see that the reliability of the Ender 3 will mean that its parts are still of decent quality in the new configuration, and that it looks as though the base printer can be reassembled should a belt-based build be a failure. Infinite bed printers will inevitably have a major presence in our community, and it is designs such as this one which will lead the way as they evolve into reliable machines.
Controlling most desktop 3D printers is as easy as sending them G-code commands over a serial connection. As you might expect, it takes a relatively quick machine to fire off the commands fast enough for a good-quality print. But what if you weren’t so picky? If speed isn’t a concern, what’s the practical limit on the type of computer you could use?
In an effort to answer that question, [Max Piantoni] set out to control his Ender 3 printer with an authentic Apple IIc. Things were made a bit easier by the fact that he really only wanted to use the printer as a 2D plotter, so he could ignore the third dimension in his code. All he needed to do was come up with a BASIC program that let him create some simple geometric artwork on the Apple and convert it into commands that could be sent out over the computer’s serial port.
Unfortunately, [Max] ran into something of a language barrier. While the Apple had no problem generating G-code the Ender’s controller would understand, both devices couldn’t agree on a data rate that worked for both of them. The 3D printer likes to zip along at 115,200 baud, while the Apple was plodding ahead at 300. Clearly, something would have to stand in as an interpreter.
The solution [Max] came up with certainly wouldn’t be our first choice, but there’s something to be said for working with what you know. He quickly whipped up a program in Unity on his Macbook that would accept incoming commands from the Apple II at 300 baud, build up a healthy buffer, and then send them off to the Ender 3. As you can see in the video after the break, this Mac-in-the-middle approach got these unlikely friends talking at last.
We’re reminded of a project from a few years back that aimed to build a fully functional 3D printer with 1980s technology. It was to be controlled by a Commodore PET from the 1980s, which also struggled to communicate quickly enough with the printer’s electronics. Bringing a modern laptop into the mix is probably cheating a bit, but at least it shows the concept is sound.
A single board computer on a desk is fine for quick demos but for taking it into the wild (or even the rest of the house) you’re going to want a little more safety from debris, ESD, and drops. As SBCs get more useful this becomes an increasingly relevant problem to solve, plus a slick enclosure can be the difference between a nice benchtop hack and something that looks ready to sell as a product. [Chris] (as ProjectSBC) has been working on a series of adaptable cases called the MagClick Case System for the LattePanda Alpha SBC which are definitely worth a look.
The LattePanda Alpha isn’t a run-of-the-mill SBC; it’s essentially the mainboard from a low power ultrabook and contains up to an Intel Core M series processor, 8GB RAM, and 64GB of eMMC. Not to mention an onboard Atmega32u4, WiFi, Gigabit Ethernet, and more. It has more than enough horsepower to be used as an everyday desktop computer or even a light gaming system if you break PCIe out of one the m.2 card slots. But [Chris] realized that such adaptability was becoming a pain as he had to move it from case-to-case as his use needs changed. Thus the MagClick Case System was born.