Making A Treadmill Into A 3D Printer

May 31, 2025 by Lewin Day 7 Comments

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.

Continue reading “Making A Treadmill Into A 3D Printer” →

Gaze Upon This Omni-directional Treadmill’s Clever LEGO Construction

January 7, 2025 by Donald Papp 16 Comments

Want to see some wildly skillful LEGO construction? Check out [Banana Gear Studios]’ omni-directional treadmill which showcases not only how such a thing works, but demonstrates some pretty impressive problem solving in the process. Construction was far from straightforward!

A 9×9 grid of LEGO shafts all turning in unison is just one of the non-trivial design challenges.

In principle the treadmill works by placing an object on a bed of identical, rotating discs. By tilting the discs, one controls which edge is in contact with the object, which in turn controls the direction the object moves. While the concept is straightforward, the implementation is a wee bit more complex. LEGO pieces offer a rich variety of mechanical functions, but even so, making a 9×9 array of discs all rotate in unison turns out to be a nontrivial problem to solve. Gears alone are not the answer, because the shafts in such a dense array are a bit too close for LEGO gears to play nicely.

The solution? Break it down into 3×3 self-contained chunks, and build out vertically with gimbals to take up the slack for gearing. Use small elastic bands to transfer power between neighbors, then copy and paste the modular 3×3 design a few times to create the full 9×9 grid. After that it’s just a matter of providing a means of tilting the discs — which has its own challenges — and the build is complete.

Check out the video below to see the whole process, which is very nicely narrated and illustrates the design challenges beautifully. You may see some similarities to Disney’s own 360° treadmill, but as [Banana Gear Studios] points out, it is a technically different implementation and therefore not covered by Disney’s patent. In an ideal world no one would worry about getting sued by Disney over an educational LEGO project posted on YouTube, but perhaps one can’t be too careful.

Continue reading “Gaze Upon This Omni-directional Treadmill’s Clever LEGO Construction” →

Here’s How That Disney 360° Treadmill Works

May 3, 2024 by Donald Papp 19 Comments

One thing going slightly viral lately is footage of Disney’s “HoloTile” infinite floor, an experimental sort of 360° treadmill developed by [Lanny Smoot]. But how exactly does it work? Details about that are less common, but [Marques Brownlee] got first-hand experience with HoloTile and has a video all about the details.

HoloTile is a walking surface that looks like it’s made up of blueish bumps or knobs of some kind. When one walks upon the surface, it constantly works to move its occupant back to the center.

Whenever one moves, the surface works to move the user back to the center.

Each of these bumps is in fact a disk that has the ability spin one way or another, and pivot in different directions. Each disk therefore becomes a sort of tilted wheel whose edge is in contact with whatever is on its surface. By exerting fine control over each of these actuators, the control system is able to create a conveyor-belt like effect in any arbitrary direction. This can be leveraged in several different ways, including acting as a sort of infinite virtual floor.

[Marques] found the system highly responsive and capable of faster movement that many would find comfortable. When walking on it, there is a feeling of one’s body moving in an unexpected direction, but that was something he found himself getting used to. He also found that it wasn’t exactly quiet, but we suppose one can’t have everything.

How this device works has a rugged sort of elegant brute force vibe to it that we find appealing. It is also quite different in principle from other motorized approaches to simulate the feeling of walking while keeping the user in one place.

The whole video is embedded just below the page break, but if you’d like to jump directly to [Marques] explaining and showing exactly how the device works, you can skip to the 2:22 mark.

Continue reading “Here’s How That Disney 360° Treadmill Works” →

What Does It Take For A LEGO Car To Roll Downhill Forever?

July 31, 2023 by Donald Papp 11 Comments

Cars (including LEGO ones) will roll downhill. In theory if the hill were a treadmill, the car could roll forever. In practice, there are a lot of things waiting to go wrong to keep this from happening. If you’ve ever wondered what those problems would be and what a solution would look like, [Brick Technology] has a nine-minute video showing the whole journey.

The video showcases an iterative process of testing, surfacing a problem, redesigning to address that problem, and then back to testing. It starts off pretty innocently with increasing wheel friction and adding weight, but we’ll tell you right now it goes in some unexpected directions that show off [Brick Technology]’s skill and confidence when it comes to LEGO assemblies.

You can watch the whole thing unfold in the video, embedded below. It’s fun to see how the different builds perform, and we can’t help but think that the icing on the cake would be LEGO bricks with OLED screens and working instrumentation built into them.

Continue reading “What Does It Take For A LEGO Car To Roll Downhill Forever?” →

Hackaday Prize 2022: Treadmill Becomes Human-Powered Generator

September 3, 2022 by Lewin Day 11 Comments

Running on a treadmill is a great way to workout, but what if the effort you put in could be put to use? This treadmill generator from [Amitabh Shrivastava] does just that.

The build starts with a regular old treadmill, which has a motor inside typically used to power the tread. Instead, the motor’s control electronics were removed, and it was repurposed to work as a generator. The output from the treadmill’s DC motor was fed directly to a DC-DC converter. This was then fed to an inverter that generates 120 V AC, which can power appliances that use up to 20-25W based on [tinkrmind’s] running performance.

It’s a fun way to generate power during a workout. If you don’t want your treadmill’s monitor to die in the middle of a Friends rerun, you’ll have to dig deep on those long runs. We’ve seen similar builds before too, with exercise bikes being a popular method of generating electricity. In fact, that’s [Amitabh]’s next project! Video after the break.

Continue reading “Hackaday Prize 2022: Treadmill Becomes Human-Powered Generator” →

Rats Learn To Play DOOM In This Automated VR Arena

December 29, 2021 by Dan Maloney 29 Comments

When we run an article with “DOOM” in the title, it’s typically another example of getting the venerable game running on some minimalist platform. This DOOM-based VR rig for rats, though, is less about hacking DOOM, and more about hacking the rats.

What started as a side project for [Viktor Tóth] has evolved into quite a complex apparatus. At the center of the rig is an omnidirectional treadmill comprised of a polystyrene ball about the size of a bowling ball. The ball is free to rotate, with sensors detecting rotation in two axes — it’s basically a big electromechanical mouse upside down. The rat rides at the top of the ball, wearing a harness to keep it from slipping off. A large curved monitor sits right in front of the rat to display the virtual environment, which is a custom DOOM map.

With the VR rig built, [Viktor] worked on automating the training. A treat dispenser provides the proper motivation, while powered drive wheels engage with the ball to nudge the rat if it gets stuck in the virtual world. [Viktor] says he has trained three rats — [Romero], [Carmack], and [Tom] — to walk down a straight hallway using this automated method. As for the meat of the game — shooting monsters — [Viktor] has that covered too, with a sensor that detects when a rat rears up on its hind legs to register a shot.

Total training time to get the rats to the point seen in the video was about six weeks, and [Viktor] reports the whole thing cost him about $2000. That’s a lot of time and money, but the results are pretty interesting. If you’re more interested in minimalist DOOM builds, we understand — check out DOOM on a lightbulb, or a thermostat, or even a GPS.

Continue reading “Rats Learn To Play DOOM In This Automated VR Arena” →

Turn Your New Years Resolution Into A Belt Grinder

February 12, 2017 by Eric Evenchick 17 Comments

We’re just over a month into the new year, and some people’s resolve on those exercise plans are already dwindling. There’s some good news though. That treadmill can be hacked into a nice belt grinder for your shop.

[Bob]’s treadmill belt grinder is based on a 2.5 horsepower motor he salvaged from a broken, donated treadmill. This motor needs 130 VDC to run, which is a bit of a challenge to generate. Fortunately, lots of treadmills seem to use the same MC-60 motor controller, which is compatible with this motor. Due to the widespread use of this controller, they can be found on eBay for about $30.

With the motor spinning, [Bob] built up a frame for the grinder, added rollers to hold the belt, and a spring based belt tensioner. The motor’s speed set point is controlled by a potentiometer, and the controller varies the power to keep a constant speed. Since the motor is capable of some serious RPM, a tachometer was added for feedback to prevent high-speed belt shredding.

The final result is a very professional looking tool for under $200. What would a grinder like this be used for? Knives of course! 2″ belt grinders are perfect for shaping and grinding knives and swords. In fact, you can see one in use in this sword hack.

Check out a video of the build after the break.

Continue reading “Turn Your New Years Resolution Into A Belt Grinder” →