3D Printed Hovercraft Takes To The Air

November 6, 2017 by John Baichtal 15 Comments

Instructables user [John_Hagy] and some classmates built an RC hovercraft as their final project in the Robotics Education Lab at NC State University. It’s a foam slab with a Hovership H2204X 2300Kv brushless motor inflating a skirt made out of ripstop nylon. Nylon is great here because it has a low friction coefficient and is nonporous to keep the air in. A second motor propels the craft, with a servo turning the whole motor assembly to steer. The team designed and 3D-printed fan holders which also help channel the air to where it’s supposed to go. Control is via a typical radio-control transmitter and receiver combo.

The project writeup includes a lot of fun detail like previous versions of the hovercraft as well as the research they undertook to learn how to configure the craft — clearly it’s their final paper put on the internet, and well done guys.

Needless to say, we at Hackaday can’t get enough of this sort of thing, as evidenced by this cool-looking hovercraft, this hovercraft made on a budget and this solar-powered ‘craft.

Freakishly Agile Crawler Rocks All-LEGO Mechanum Wheels

November 4, 2017 by John Baichtal 9 Comments

Mechanum wheels are great, but you have to have them perfectly alined or they come across a little clunky, giving your robot a herky-jerky movement. Robotics educator and supreme LEGO builder [Yoshihito Isogawa] built a mechanum-wheeled rover that has the angles right: each wheel consists of 12 smaller rubber tires angled at 45 degrees. The key to the project is Part Number 85940, accurately if unsexily named “double Ø4.85 hole w/ Ø3.2 shaft”. It consists of a double technic hole with a shaft projecting in a 45-degree angle.

Unlike his omni-roller project with 3 large wheels and the mechanum tank treads he built for another project, this one features the gold standard of mechanum movement: creepy agility. He also did a version with 9 side rollers per wheel, and it was nearly as stable.

Hackaday loves [Yoshihito]’s great creations, which are as beautiful and elegant as they are functional. His all-LEGO centrifugal pump and his spirograph machine make expert use of parts to make the builds as simple as possible.

Continue reading “Freakishly Agile Crawler Rocks All-LEGO Mechanum Wheels” →

Mini Millennium Falcon Is Envy Of The Neighborhood

November 3, 2017 by Tom Nardi 19 Comments

Here’s a tip for any readers who may be expecting a child in the near future: there’s about a two year period where you can basically use your child as a Halloween prop. They’re too young to express any serious interest in what they want to dress up as, and as an added bonus, they generally spend most of their time being rolled around in a wheeled contraption anyway. As long as you can keep the little one warm and securely seated in the thing, you’ve essentially got free reign to put them into all sorts of elaborate vehicles.

Case in point, the awesome build that [shnatko] has dubbed the “Millennium Flyer”. Built atop his daughter’s plastic Radio Flyer wagon, the Millennium Flyer is constructed out of wood and foam board. By using the mounting holes in the wagon originally intended for an optional canopy, the ship itself can be removed to fly again next year.

[shnatko] notes that he possess no particular talent for the fine arts, so he decided to skin his build by printing out a high resolution image of the Millennium Falcon he found online. The amount of patience (not to mention printer ink) that this method took is considerable, but we think the final results speak for themselves.

To finish off his build [shnatko] found a blue cold cathode light from his PC modding days and rigged it up with a laptop battery he had laying around. Some foam ribs and wax paper to diffuse the light give it that iconic look from the “real” Falcon.

Between this build and the AT-AT rocking horse from a few weeks back, it seems we are in the golden age of childhood Star Wars conveyances. Though we wouldn’t mind seeing this get mounted to a racing Power Wheels either.

Mechanical Marvel Trades Courage For Chocolate

October 30, 2017 by Steven Dufresne 4 Comments

When we see what [Jason Allemann] does with LEGO, we wonder why more one-offs aren’t made this way. This time he’s made a Halloween mechanical marvel that will surely scare more kids than anything else they’ll encounter on their rounds — so much so that many may even decline the chocolate it dispenses. Who wouldn’t when to get it you have to reach over an animatronic skeleton hand that may grab you while a similarly mechanized spider may lunge onto your hand.

The chocolate dispensing, the hand and the spider are all animated using four motors, a LEGO Mindstorms EV3 brick to control them, and a touch sensor. When a kid presses a pumpkin attached to the touch sensor, the next chocolate candy is lowered by gravity onto a conveyor belt and carried forward to the awaiting child. That much is automatic. At the discretion of [Jason] and his partner [Kristal], using an infrared remote control and sensor, they can activate the skeleton hand and the lunging spider at just the right moment. We’re just not sure who they’ll choose to spare. It is Halloween after all, and being scared is part of the fun, so maybe spare no one? Check out the video below and tell us if you’d prefer just the treat, or both the trick and treat.

We do have to wonder if there’s any project that can’t benefit from LEGO products, even if only at the prototype stage or to help visualize an idea. As a small sample, [Jason]’s also made a remote-controlled monowheel and an actual working printer along with a Morse key telegraph machine to send it something to print.

Continue reading “Mechanical Marvel Trades Courage For Chocolate” →

Restoring A Tonka Truck With Science

October 26, 2017 by Tom Nardi 36 Comments

The yellow Tonka Truck. Instantly recognizable by any child of decades past, that big metal beast would always make you popular around the sandbox. There were no blinking lights to dazzle, no noises to be heard (unless you count the hard plastic wheels rolling on concrete), even the dumping action is completely manual. But back then, it was a possession to be treasured indeed.

So it’s perhaps no surprise that there is a certain following for these classic trucks today, though like with most other collectibles, a specimen in good condition can be prohibitively expensive. The truck that [PoppaFixIt] found in the trash was certainly not one of those specimens, but with some patience and knowledge of basic chemistry, he was able to bring this vintage toy back to the present.

The first step was to disassemble the truck. Before they switched over to Chinese mass production, these trucks were built with actual rivets. After drilling them out and unfolding the little metal tabs that toy makers loved back in the day, he was able to separate the metal body of the truck from the plastic detail bits. The plastic parts just needed a fresh coat of paint, but the rusted metal body would need a bit more attention.

Remembering a tip he read online, [PoppaFixIt] decided to attempt electrolytic rust removal to get the metal parts back into serviceable condition. A big plastic bin, some washing soda, and old steel window weights for his sacrificial anodes was all the equipment he needed for the electrolysis tank. To power the chemical reaction he used a standard 12 volt car battery and charger wired in parallel; this step is important, as he notes most newer chargers are smart enough not to work unless they see a real battery connected.

After running the setup overnight, the collected rust and junk on the window weights was proof enough the process worked. From there, it was just a fresh coat of yellow paint, a new sticker kit from eBay, and his Tonka truck was ready to face another 30+ years of service.

If you’re looking to restore things larger than a child’s toy, you may be interested in the much larger electrolytic setup we’ve covered previously. Of course if you’re really pressed for time, you could try blasting the rust away with a laser.

Imperial Rocker For Stopping Tiny Rebel Scum

October 25, 2017 by Tom Nardi 15 Comments

Some of the luckiest kids in the world have to be the ones with hackers and makers as parents. While normal kids are stuck playing with cookie cutter mass produced toys, these kids get one-off gadgets and creations that will be the envy of the playground. Frankly, some of the stuff ends up being so cool that it’ll get the adults wishing they could go back in time and play with it.

One such parent, and one such project, is the Imperial Rocker by [Matthew Regonini]. Hoping to instill an obsession with a galaxy far, far, away on his offspring, [Matthew] designed this AT-AT rocking horse piece by piece in Illustrator, and then cut it all out of birch using his XCarve CNC router. Each piece was then meticulously glued together to produce a final 3D effect from the individual cutouts.

With a liberal application of spring clamps to hold it all together while it dried, all that was left to do was painstakingly sand all the parts so the edges of the laminated construction would be smooth. Dowels were then added for the handlebars and foot pegs, and a few coats of polyurethane seal up the plywood while bringing out a natural look.

[Matthew] notes some issues here and there, notably quite a bit of blowout in some of the detail cuts and a couple miscalculated dimensions. But he reasons that the rocker is going to live a pretty hard life anyway, so best not to sweat the small stuff.

While the Imperial Rocker has that quaint old-school charm, we wonder how long it will be before [Matthew’s] little Stormtrooper starts yearning for the blinking lights and buttons that youngsters just can’t get enough of.

Continue reading “Imperial Rocker For Stopping Tiny Rebel Scum” →

Cheap RC Truck Mod Is Slightly Risky Fun

October 19, 2017 by Tom Nardi 32 Comments

The world of RC can be neatly split into two separate groups: models and toys. The RC models are generally big, complex, and as you’d imagine, more expensive. On the other hand, the RC toys are cheap and readily available. While not as powerful or capable as their more expensive siblings, they can often be a lot of fun; especially since the lower costs means a crash doesn’t put too big of a ding into to your wallet.

With his latest mod, [PoppaFixIt] has attempted to bridge the gap between toy and model by sticking a considerably overpowered battery into a $10 RC truck from Amazon. He reports greatly improved performance from his hacked together truck, but anyone looking to replicate his work should understand the risks before attempting to hack up their own version.

The principle is pretty simple; the truck is designed to run on two AA batteries, providing 3 volts. But by swapping the AAs out for a 3.7 volt 1S LiPo of the type that’s used in small airplanes and quadcopters, you can get an instant boost in power. As a happy side effect, the LiPo batteries are also rechargeable and fairly cheap, so you won’t have to keep burning through alkaline AAs.

The mod itself is a basic job that only requires a few bucks in parts, and for which [PoppaFixIt] has helpfully provided Amazon links. Essentially you just crack open the truck, solder a JST connector pigtail to the positive and negative traces on the PCB, and then pop a hole in the roof to run the new battery wires out.

Right about now the RC purists are probably screaming obscenities at their displays, and not without reason. As fun as these supercharged little trucks are to drive, there are a number of real issues here which need to be mentioned.

First, while the motor will probably be alright with a bit higher voltage running through them, the gears won’t be liking it one bit. In fact, [PoppaFixIt] even mentions they shredded a few gears when they tried to take one off-road. The second issue is that since these vehicles were not designed with LiPo batteries in mind, there’s no low voltage cutoff to prevent over discharge. If you aren’t careful, a setup like this will cook those cute little batteries in short order. But hey, at least it’s all cheap.

If you are more interested in control than power, you may want to check out the previous hacks we’ve featured. Seems like these little RC trucks are the platform of choice for hackers who want to get stuff moving on the cheap.