Tooling around downtown on a personal electric vehicle is a lot of fun, but it is even better when you do like [James Dietz] and ride on your own 3D-printed electric scooter. As one of the entries for the Hackaday Prize, RepRaTS (Replicable Rapid prototyper Transportation System) has a goal of doing for scooters what the original RepRap project did for 3D printing: provide a user-friendly design base that you can extend, modify, and maintain. It doesn’t even require power tools to build, other than, of course, your 3D printer.
The design uses threaded rods and special plastic spacers made to hold a large load. The prototype is deliberately oversized with large hub motors, with the understanding that most builds will probably be smaller. As you can see in the video below, the scooter seems to go pretty fast and handles well.
Need a steel beam? You can 3D print PLA beams that are as strong as a steel beam of equivalent weight according to [RepRap]. The Python code for FreeCAD generates a repeating structure especially well suited for belt printers that can print a beam of any length. Keep in mind, of course, given two things that weigh the same, if one is made of steel and the other PLA, the steel one will be physically smaller.
The beams are repeating tetrahedrons which are quite strong with a lot of material on the outer faces to resist bending. Each beam end has a neat block with a wiring hole and a ring of small holes that allow you to mount the beams to things or each other with 30 degree increments of rotation.
3D printers are capable of creating complex geometries with a minimum of fuss, but one of the tradeoffs is the long period of time it takes to print a part. Often, printers are left to run for many hours with a minimum of supervision to complete their tasks. This can leave printers idling for long periods of time after their work is finished. Noting this, [TheGrim] put together the Advanced Printer Control.
The aim of the APC is to monitor 3D printers, and shut them off when their work is complete. The aim is to avoid leaving printers running for hours after their prints are finished, which causes needless wear on fans and screens which can have a limited life. This is achieved by putting an ESP8266 in charge of the printer’s AC power supply, via a triac. It measures the current drawn by the printer when idling and in use to set a baseline. Then, whenever the printer drops back to idle levels, a timer begins. When the timer runs out, the printer is switched off. There’s also an option to automatically trigger shutdown with an I/O pin, too.
Despite the impressive variety of thermoplastics that can be printed on consumer-level desktop 3D printers, the most commonly used filament is polylactic acid (PLA). That’s because it’s not only the cheapest material available, but also the easiest to work with. PLA can be extruded at temperatures as low as 180 °C, and it’s possible to get good results even without a heated bed. The downside is that objects printed in PLA tend to be somewhat brittle and have a low heat tolerance. It’s a fine plastic for prototyping and light duty projects, but it won’t take long for many users to outgrow its capabilities.
The next step up is usually polyethylene terephthalate glycol (PETG). This material isn’t much more difficult to work with than PLA, but is more durable, can handle higher temperatures, and in general is better suited for mechanical parts. If you need greater durability or higher heat tolerance than PETG offers, you could move on to something like acrylonitrile butadiene styrene (ABS), polycarbonate (PC), or nylon. But this is where things start to get tricky. Not only are the extrusion temperatures of these materials greater than 250 °C, but an enclosed print chamber is generally recommended for best results. That puts them on the upper end of what the hobbyist community is generally capable of working with.
Industrial 3D printers like the Apium P220 start at $30,000.
But high-end industrial 3D printers can use even stronger plastics such as polyetherimide (PEI) or members of the polyaryletherketone family (PAEK, PEEK, PEKK). Parts made from these materials are especially desirable for aerospace applications, as they can replace metal components while being substantially lighter.
These plastics must be extruded at temperatures approaching 400 °C, and a sealed build chamber kept at >100 °C for the duration of the print is an absolute necessity. The purchase price for a commercial printer with these capabilities is in the tens of thousands even on the low end, with some models priced well into the six figure range.
Of course there was a time, not quite so long ago, where the same could have been said of 3D printers in general. Machines that were once the sole domain of exceptionally well funded R&D labs now sit on the workbenches of hackers and makers all over the world. While it’s hard to say if we’ll see the same race to the bottom for high temperature 3D printers, the first steps towards democratizing the technology are already being made.
3D printed parts are generally no way near the strength of an equivalent injection moulded part and techniques such as a sustained heat treatment, though effective usually distort the part beyond use.
[CNC Kitchen] was investigating the results (video, embedded below) of a recent paper, that described a novel ABS filament reinforced by a “star” shaped Polycarbonate core, an arrangement the authors claim is resilient to deformation during the annealing process often necessary to increase part strength. While the researchers had access to specialised equipment needed to manufacture such a composite material, [CNC Kitchen’s] solution of simply using his dual extruder setup to directly print the required hybrid filament is something we feel, strongly resonates with the now old school, RepRap “print your printer” sentiment.
The printed filament seems to have reasonable dimensional accuracy and passing the printed spool through a heater block without the nozzle attached, ensured there would be no obvious clogs. The rest of the video focuses on a very thorough comparison of strength and deformation between the garden variety Polycarbonate, ABS and this new hybrid filament after the annealing process. Although he concludes with mixed results, just being able to combine and print your own hybrid filament is super cool and a success in its own right!
There was a time when the curious hardware hacker had to build their own 3D printer, because commercial models were so expensive as to be unaffordable except by well-funded institutions. We’re fortunate then to live in an era in which a good quality off-the-shelf machine can be had without breaking the bank, but that is not to say that home-made 3D printers are a thing of the past. Instead the community of rapid prototyping experimenters continue to push the boundaries of the art, and from that we all benefit. An example comes from [Morgan Lowe], whose 3DLS lead screw driven 3D printer joins the freely downloadable designs to be found on Thingiverse.
If at first sight you think it looks a little familiar, you are correct, as it takes its frame design from the popular AM8 metal frame upgrade for the Anet A8 off-the-shelf printer. It draws heavily from other A8 upgrades, and brings in some parts such as the extruder and bed from the Creality Ender3. This is the beauty of incremental open source, and the result is a belt-free printer that does a decent-looking Benchy on the bench, and as a party piece manages to print a slightly more hairy little plastic boat when suspended at 45 degrees by a rope from the ceiling.
When dipping a toe into the world of home made 3D printers it’s interesting to take a look into some of the earlier Hackaday RepRap posts, and see how far we’ve come.
MakerBot was poised to be one of the greatest success stories of the open source hardware movement. Founded on the shared knowledge of the RepRap community, they created the first practical desktop 3D printer aimed at consumers over a decade ago. But today, after being bought out by Stratasys and abandoning their open source roots, the company is all but completely absent in the market they helped to create. Cheaper and better printers, some of which built on that same RepRap lineage, have completely taken over in the consumer space; forcing MakerBot to refocus their efforts on professional and educational customers.
This fundamental restructuring of the company is perhaps nowhere more evident than in the recent unveiling of “SKETCH Classroom”: an $1,800 package that includes lesson plans, a teacher certification program, several rolls of filament, and two of the company’s new SKETCH printers. It even includes access to MakerBot Cloud, a new online service that aims to help teachers juggle student’s print jobs between multiple SKETCH printers.
Of course, the biggest takeaway from this announcement for the average Hackaday reader is that MakerBot is releasing new hardware. Their last printer was clearly not designed (or priced) for makers, and even a current-generation Replicator costs more than the entire SKETCH Classroom package. On the surface, it might seem like this is a return to a more reasonable pricing model for MakeBot’s products; something that could even help them regain some of the market share they’ve lost over the years.
There’s only one problem, MakerBot didn’t actually make the SKETCH. This once industry-leading company has now come full-circle, and is using a rebranded printer as the keystone of their push into the educational market. Whether they were unable to build a printer cheap enough to appeal to schools or simply didn’t want to, the message is clear: if you can’t beat them, join them.
