Stingrays have an elegant, undulating swimming motion that can be hypnotic. [Vimal Patel] re-created this harmony with his fantastic mechanical mechanical stingray using LEGO pieces and a LEGO Technics Power Functions motor. The motor is set in a clever arrangement that drives the motion remotely, so that it and electrical elements can stay dry.
The mechanical stingray sits at the end of a sort of rigid umbilical shaft. This shaft connects the moving parts to the electrical elements, which float safely on the surface. This leaves only the stingray itself with its complex linkages free to move in the water, while everything else stays above the waterline.
He started by attaching a ready made puppet to a classic Radio Flyer dual deck toddler tricycle using zip ties and split pipe insulation to give the limbs stiffness. [Donald] then put all the electronics, including the 12 V 50 RPM DC motor, 24 V 22.4 Ah Li-Ion battery pack, TB67H420FTG motor driver, and the Arduino Uno microcontroller under the back axle.
The motor transfers power to one of the back wheels via pulleys and timing belts with an additional ASMC-04B 24 V servo used to steer the tricycle via a steel pushrod. The RC communication is done with a FlySky FS-GT2 2.4 GHz 2-channel system. [Donald] gives a detailed list of parts that he uses in a Google doc for anyone wanting to know more.
[Donald] goes into great length about the limitations of the build, including the low clearance of the electronics underneath, the finicky nature of the timing belts and the “uncanny valley” that the size of the puppet induces to a casual observer. Regardless, the build is exceptional and paves the way for a variety of improvements for anyone wanting to extend the idea either further into the creepy or cute domain.
Retrofitting vehicles with motorized control are a crowd favorite, as seen with some projects like a stroller controller from Maker Faires of the past.
It might be surprising for some, but humans actually evolved to be long-distance runners. We aren’t very fast comparatively, but no other animal can run for as long or as far as a human can. Sitting at a desk, on the other hand, is definitely not something that we’re adapted to do, so it’s important to take some measures to avoid many of the problems that arise for those that sit at a desk or computer most of the day. This build takes it to the extreme, not only implementing a standing desk but also a ton of automation for that desk as well.
This project is an improvement on a prior build by [TJ Horner] called the WiFi Standing Desk Controller. This new version has a catchier name, and uses an ESP32 to run the show. The enclosure is 3D printed and the control board includes USB-C and a hardware UART to interface with the controller. The real perks of this device are the automation, though. The desk can automatically lift if the user has been sitting too long, and could also automatically lift if it detects no one is home (to help keep a cat off of the desk, for example). It also includes presets for different users, and can export data to other software to help analyze sitting and standing patterns.
The controller design is open source and could be adapted to work on a wide-array of powered desks. As we’ve seen in the past, with the addition of a motor, even hand-crank standing desks can be upgraded. If you haven’t gotten into the standing desk trend yet, we hope that you are at least occasionally going for a run.
While the core mechanism is largely the same, the powered unit uses a N20 geared motor and an 18650 cell. There’s no fancy motor controller here — just flip the switch and you’ve got 30 RPMs worth of stair-steppin’ action. When you’ve run the cell down, and you will, there’s an onboard TP4056 charging module to keep the good times rolling.
[AlexY] hasn’t had a chance to document the build process for the motorized version of the escalator, but as most of the parts are compatible with the manual version, you should be able to figure it out by referencing the earlier assembly guide.
Once you get tired of printing keychains and earbud holders with your 3D printer, you’ll want to design things a bit more sophisticated. How about things that rotate? [3DSage] has a good how-to about how to integrate a simple motor and controller into a few different size boxes. Combined with some 3D printed linkages, these boxes can turn your project — printed or otherwise — into something that spins.
To demonstrate, he created a few cat toys, played with an idea for a magic trick, and refit a selfie light into… something. We have no doubt you can find something to do with these little motor modules. The boxes vary mostly in how big the battery packs are. There are also several interesting side pieces like a 3D holder for rechargeable button cells and their charger.
In addition, he also demonstrates how to use the motor as a (rather poor) generator. Attaching a water wheel wasn’t a success until he used compressed air to run the wheel. You would have thought water would have done the trick.
The video stresses that you should solder connections, but you don’t have to. Honestly, we think if you are building moving stuff with a 3D printer, you should probably just go ahead and learn to solder. It isn’t that hard and there are plenty of reasons to learn.
They might not be the hoverboards we were promised in Back to the Future II, but the popular electric scooters that have commandeered the name are exciting pieces of tech in their own way. Not because we’re looking to make a fool of ourselves by actually riding one, but because they’re packed full of useful hardware that’s available for dirt cheap thanks to the economies of scale and the second-hand market.
The project starts by liberating the four wheel motors from the scooters and carefully cutting down the frame to preserve the mounting hardware. These mounts are ultimately welded to the frame of the rover, with a piece of diamond plate screwed down on top. On the bottom, [MakerMan] mounts the two control boards and a custom fabricated 36 V battery pack.
He doesn’t go into any detail on how he’s interfacing the RC hardware with the motor controllers, but as we’ve seen with past hacks, there’s open source firmware replacements for these boards that allow them to be controlled by external inputs. Presumably something similar is being used here, but we’d be interested to hear otherwise. Of course you could swap the RC hardware out for a microcontroller or Raspberry Pi if you were looking to make some kind of autonomous rover.
Many dream of tooling around in a high performance sports car, but the cost of owning, maintaining, and insuring one of them make it a difficult proposition. While this LEGO version of the Corvette ZR1 might not be exactly like the real thing, it’s 4-speed manual and electronic gauge cluster can give you a taste of the supercar lifestyle without having to taken out a second mortgage.
Built by [HyperBlue], this desktop speedster has more going on under the hood (or more accurately, the roof) than you might expect. While it looks pretty unassuming from the outside, once the top is lifted, you can see all the additional components that have been packed in to motorize it. The functional gearbox takes up almost the entire interior of the car, but it’s not like you were going to be able to fit in there anyway.
But the motorized car is really only half of the project. [HyperBlue] has built a chassis dynamometer for his plastic ride that not only allows you to “start” the engine with realistic sights and sounds (recorded from an actual GM LT1 V8 engine), but put the mini ‘Vette through its paces. With a virtual dashboard powered by the Raspberry Pi, you can see various stats about the vehicle such as throttle position, RPM, and calculated scale speed; providing a real-world demonstration of how the transmission operates.