With the newer generation of quick and reliable 3D printers, we find ourselves with the old collecting dust and cobwebs. You might pull it out for an emergency print, that is if it still works… In the scenario of an eternally resting printer (or ones not worth reviving), trying to give new life to the functional parts is a great idea. This is exactly what [MarkMakies] did with a simple RC rover design from an old Makerbot Replicator clone. 

Using a stepper motor to directly drive each wheel, this rover proves its ability to handle a variety of terrain types. Stepper motors are far from the most common way to drive an RC vehicle, but they can certainly give enough power. Controlling these motors is done from a custom protoboard, allowing the use of RC control. Securing all these parts together only requires a couple of 3D printed parts and the rods used to print them. Throw in a drill battery for power, and you can take it nearly anywhere! 

With the vehicle together [MarkMakies] tested to a rocketing 0.6 m/s fully loaded 4WD. Of course, less weight proves more exciting. While [Mark] recognizes some inherent issues with a stepper-driven all-terrain vehicle, we could see some clever uses for the drive system.

Broken down 3D printers are a dime a dozen, so you should try making something similar by checking out [Mark]’s design files! 3D printers are machines of fine-controlled movement so it’s no surprise to find reuse in these projects is fairly common. Just like this nifty DIY camera slider!

We all love combat robotics for its creative problem solving; trying to fit drivetrains and weapon systems in a small and light package is never as simple as it appears to be. When you get to the real lightweights… throw everything you know out the window! [Shoverobotics] saw this as a barrier for getting into the 150g weight class, so he created the combat robotics platform named Project SVRN.

You want 4-wheel drive? It’s got it! Wedge or a Grabber? Of course! Anything else you can imagine? Feel free to add and modify the platform to your heart’s content! Controlled by a Malenki Nano, a receiver and motor controller combo board, the SVRN platform allows anyone to get into fairyweight fights with almost no experience.

With 4 N10 motors giving quick control, the platform acts as an excellent platform for various bot designs. Though the electronics and structure are rather simple, the most important and impressive part of Project SVRN is the detailed documentation for every part of building the bot. You can find and follow the documentation yourself from [Shoverobotics]’s Printables page here!

If you already know every type of coil found in your old Grav-Synthesized Vex-Flux from your Whatsamacallit this might not be needed for you, but many people trying to get into making need a ramp to shoot for the stars. For those needing more technical know-how in combat robotics, check out Kitten Mittens, a bot that uses its weapon for locomotion!

For all the remarkable improvements we’ve seen in desktop 3D printers, metal printers have tended to stay out of reach for hackers, mostly because they usually rely on precise and expensive laser systems. This makes it all the more refreshing to see [Dan Gelbart]’s demonstration of Rapidia’s cast-to-sinter method, which goes from SLA prints to ceramic or metal models.

The process began by printing the model in resin, scaled up by 19% to account for shrinkage. [Dan] then used the resin print to make a mold out of silicone rubber, after first painting the model to keep chemicals from the resin from inhibiting the silicone’s polymerization. Once the silicone had set, he cut the original model out of the mold and prepared the mold for pouring. He made a slurry out of metal powder and a water-based binder and poured this into the mold, then froze the mold and its contents at -40 ℃. The resulting mixture of metal powder and ice forms a composite much stronger than pure ice, from which [Dan] was able to forcefully peel back the silicone mold without damaging the part. Next, the still-frozen part was freeze-dried for twenty hours, then finally treated in a vacuum sintering oven for twelve hours to make the final part. The video below the break shows the process.

A significant advantage of this method is that it can produce parts with much higher resolution and better surface finish than other methods. The silicone mold is precise enough that the final print’s quality is mostly determined by the fineness of the metal powder used, and it’s easy to reach micron-scale resolution. The most expensive part of the process is the vacuum sintering furnace, but [Dan] notes that if you only want ceramic and not metal parts, a much cheaper ceramic sintering oven will work better.

We’ve seen sintering-based metal printers a few times before, as well a few more esoteric methods. We’ve also covered a few of [Dan]’s previous videos on mechanical prototyping methods and building a precision CNC lathe.

Thanks to [Eric R Mockler] for the tip!

Stripping and cutting wires can be a tedious and repetitive part of your project. To save time in this regard, [Red] built an automatic stripper and cutter to do the tiring work for him.

An ESP32 runs the show in this build. Via a set of A4988 stepper motor drivers, it controls two NEMA 17 stepper motors which control the motion of the cutting and stripping blades via threaded rods. A third stepper controls a 3D printer extruder to move wires through the device. There’s a rotary encoder with a button for controlling the device, with cutting and stripping settings shown on a small OLED display. It graphically represents the wire for stripping, so you can select the length of the wire and how much insulation you want stripped off each end. You merely need select the measurements on the display, press a button, and the machine strips and cuts the wire for you. The wires end up in a tidy little 3D-printed bin for collection.

The build should be a big time saver for [Red], who will no longer have to manually cut and strip wires for future builds. We’ve featured some other neat wire stripper builds before, too. Video after the break.

You can buy all sorts of RC cars off the shelf, but doing so won’t teach you a whole lot. Alternatively, you could follow [TRDB]’s example, and design your own from scratch.

The Lizard, as it is known, is a fun little RC car. It’s got a vaguely Formula 1-inspired aesthetic, and looks fetching with the aid of two-tone 3D printed parts. It’s designed for speed and handling, with a rear-wheel-drive layout and sprung suspension at all four corners to soak up the bumps. The majority of the vehicle is 3D printed in PETG, including the body and the gearbox and differential. However, some suspension components are made in TPU for greater flexibility and resistance to impact. [TRDB] specified commercial off-the-shelf wheels to provide good grip that couldn’t easily be achieved with 3D-printed tires. An ESP32 is responsible for receiving commands from [TRDB’s] custom RC controller running the same microcontroller. It sends commands to the speed controller that runs the Lizard’s brushed DC motor from a 3S lithium-polymer battery.

The final product looks sleek and handles well. It also achieved a GPS-verified top speed of 48 km/h as per [TRDB’s] testing. We’ve seen some other great DIY RC cars over the years, too, like this example that focuses on performance fundamentals. Video after the break.

A treadmill-style bed can be a great addition to a 3D printer. It allows prints to be shifted out of the build volume as printing continues, greatly increasing the size and flexibility of what you can print. But [Ivan Miranda] and [Jón Schone] had a question. Instead of making a treadmill to suit a 3D printer, what if you just built a 3D printer on top of a full-size treadmill?

The duo sourced a piece of real gym equipment for this build. They then set about building a large-scale 3D printer on top of this platform. The linear rails were first mounted on to the treadmill’s frame, followed by a gantry for the print head itself and mounts for the necessary stepper motors. The printer also gained a custom extra-large extruder to ensure a satisfactory print speed that was suitable for the scale of the machine. From there, it was largely a case of fitting modules and running cables to complete the printer.

Soon enough, the machine was printing hot plastic on the treadmill surface, thereby greatly expanding the usable print volume. It’s a little tricky to wrap your head around at first, but when you see it in action, it’s easy to see the utility of a build like this, particularly at large scale. [Ivan] demonstrated this by printing a massive girder over two meters long.

We started seeing attempts at building a belt-equipped “infinite build volume” printer back in 2017, and it took awhile before the concept matured enough to be practical. Even today, they remain fairly uncommon.

Typewriters aren’t really made anymore in any major quantity, since the computer kind of rained all over its inky parade. That’s not to say you can’t build one yourself though, as [Toast] did in a very creative fashion.

After being inspired by so many typewriters on YouTube, [Toast] decided they simply had to 3D print one of their own design. They decided to go in a unique direction, eschewing ink ribbons for carbon paper as the source of ink. To create a functional typewriter, they had to develop a typebar mechanism to imprint the paper, as well as a mechanism to move the paper along during typing. The weird thing is the letter selection—the typewriter doesn’t have a traditional keyboard at all. Instead, you select the letter of your choice from a rotary wheel, and then press the key vertically down into the paper. The reasoning isn’t obvious from the outset, but [Toast] explains why this came about after originally hitting a brick wall with a more traditional design.

If you’ve ever wanted to build a typewriter of your own, [Toast]’s example shows that you can have a lot of fun just by having a go and seeing where you end up. We’ve seen some other neat typewriter hacks over the years, too. Video after the break.

[Thanks to David Plass for the tip!]

When you start building lots of something, you’ll know the value of accurate fixturing. [Chris Borge] learned this the hard way on a recent mass-production project, and decided to solve the problem. How? With a custom fixturing tool! A 3D printed one, of course.

Chris’s build is simple enough. He created 3D-printed workplates covered in a grid of specially-shaped apertures, each of which can hold a single bolt. Plastic fixtures can then be slotted into the grid, and fastened in place with nuts that thread onto the bolts inserted in the base. [Chris] can 3D print all kinds of different plastic fixtures to mount on to the grid, so it’s an incredibly flexible system.

3D printing fixtures might not sound the stoutest way to go, but it’s perfectly cromulent for some tasks. Indeed, for [Chris]’s use case of laser cutting, the 3D printed fixtures are more than strong enough, since the forces involved are minimal. Furthermore, [Chris] aided the stability of the 3D-printed workplate by mounting it on a laser-cut wooden frame filled with concrete. How’s that for completeness?

We’ve seen some other great fixturing tools before, too. Video after the break.

RepRap was the origin of pushing hobby 3D printing boundaries, and here we see a RepRap scaled down to the smallest detail. [Vik Olliver] over at the RepRap blog has been working on getting a printer working printing down to the level of micron accuracy.

The printer is constructed using 3D printed flexures similar to the OpenFlexure microscope. Two flexures create the XYZ movement required for the tiny movements needed for micron level printing. While still in the stages of printing simple objects, the microscopic scale of printing is incredible.

[Vik] managed to print a triangular pattern in resin at a total size of 300 µm. For comparison SLA 3D printers struggle at many times that scale. Other interesting possibilities from this technology could be printing small scale circuits from conductive resins, though this might require some customization in the resin department.

In addition to printing with resin, µRepRap can be seen making designs in marker ink such as our own Jolly Wrencher! At only 1.5 mm the detail is impressive especially when considering the nature of scratching away ink.

If you want to make your own µRepRap head over to [Vik Olliver]’s GitHub. The µRepRap project has been a long going project. From the time it started the design has changed quite a bit. Check out an older version of the µRepRap project based around OpenFlexure!

Despite the best efforts of the RepRap community over the last twenty years, self-replicating 3D printers have remained a stubbornly elusive goal, largely due to the difficulty of printing electronics. [Brian Minnick]’s fully-printed 3D printer could eventually change that, and he’s already solved an impressive number of technical challenges in the process.

[Brian]’s first step was to make a 3D-printable motor. Instead of the more conventional stepper motors, he designed a fully 3D-printed 3-pole brushed motor. The motor coils are made from solder paste, which the printer applies using a custom syringe-based extruder. The paste is then sintered at a moderate temperature, resulting in traces with a resistivity as low as 0.001 Ω mm, low enough to make effective magnetic coils.

Brushed motors are less accurate than stepper motors, but they do have a particularly useful advantage here: their speed can be controlled simply by varying the voltage. This enables a purely electromechanical control system – no microcontroller on this printer! A 3D-printed data strip encodes instructions for the printer as holes in a plastic sheet, which open and close simple switches in the motor controller. These switches control the speed, direction, and duration of the motors’ movement, letting the data strip encode motion vectors.

Remarkably, the hotend on this printer is also 3D-printed. [Brian] took advantage of the fact that PEEK’s melting point increases by about 110 ℃ when it’s annealed, which should allow an annealed hotend to print itself. So far it’s only extruded PLA, but the idea seems sound.

The video below the break shows a single-axis proof of concept in action. We haven’t been able to find any documentation of a fully-functional 3D printer, but nevertheless, it’s an impressive demonstration. We’ve covered similar printers before, and if you make progress in this area, be sure to send us a tip.