Functioning Technic SLJ900 Bridge Builder

There is definitely a passion for detail and accuracy among LEGO builders who re-create recognizable real-world elements such as specific car models and famous buildings. However, Technic builders take it to a level the regular AFOLs cannot: Not only must their model look like the original, it has to function the same way. Case in point, [Wolf Zipp]’s version of a massive bridge-building rig. The Chinese-built SLJ900 rolls along the tops of bridges and adds ginormous concrete spans with the aplomb found only in sped-up YouTube videos. It is nevertheless a badass robot and a worthy target for Technicization.

[Wolf]’s model is 2 meters long and weighs 10.5kg, consisting of 13 LEGO motors and a pneumatic rig, all run by a handheld control box. The rig inserts LEGO connectors to a simulated bridge span, lifts it up, moves it over the next pier, then drops it down into place. The span weighs 2.5kg by itself — that ain’t no styrofoam! There are a lot of cool details in the project. For instance, the mechanism that turns the wheels for lateral movement consists of a LEGO-built pneumatic compressor that trips pneumatic actuators that lift the wheels off the ground and allows them to turn 90 degrees.

Sometimes it blows the mind what can be built with Technic. Check out this rope-braiding machine and this 7-segment display we’ve posted. Continue reading “Functioning Technic SLJ900 Bridge Builder”

Play A Claw Machine From Your Armchair

Have you ever been seduced by a claw machine in an arcade, only to have your hopes of a cuddly toy dashed as it fails to hang onto your choice? Then you’re in luck, because now you can play to your heart’s content online. [Ryan Walmsley] wants you to control his Raspberry Pi-driven claw machine.

Hardware-wise he’s replaced the original 8052 microcontroller and relay control with the Pi and a custom H-bridge PCB. We particularly light the warning: “Highish voltage”, and we feel it should appear more often. There is some code in his GitHub repository, but we suspect it doesn’t have everything.

We had a lot of fun digging into the documentation on this one. From his initial thoughts through some prototyping and a board failure, to the launch of the online version and finally a run-down of how it all works, he’s got it covered.

Sadly the machine itself isn’t online all the time, it seems to be only online when [Ryan] is at home, so if you live on the other side of the world from his British base you may be out of luck. Fortunately though his previous live streams are online, so you can see it in action on a past outing below the break.

Of course what kind of swag do you load up in a claw machine like this one? On his Twitter feed we’ve seen tests of the aliens from Toy Story (who start their existence in a claw machine so quite fitting). The majority of items show in is recorded games — now numbering over 2000 — have been our beloved companion cube.

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Mindstorms Forkliftbots Gonna Take Your Job

With every advance in robotics, we get closer to being able to order stuff from Amazon and have no human being participate in its delivery. Key step in this dream: warehouse robots, smart forklifts able to control and inventory and entire warehouse full of pallets, without the meat community getting involved. [Thomas Risager] designed just such a system as part of his Masters Thesis in Software Engineering. It consists of five LEGO Mindstorms robots working in concert (video embedded below), linked via WiFi to a central laptop. Mindstorms’ native OS doesn’t support WiFi (!!!) so he reflashed the EV3’s ARM9 chip with software developed using Java and running under LeJOS. On the laptop side [Thomas] wrote a C++ application that handles the coordination and routing of the forklifts. We can see a lot of weary forklift drivers ready to kick back and let a robot have the full-time job for a change.

The robots use WiFi to a central laptop. Mindstorms’ native OS doesn’t support WiFi (!!!) so [Thomas] reflashed the EV3’s ARM9 chip with software developed using Java and running under LeJOS. On the laptop side he wrote a C++ application that handles the coordination and routing of the forklifts. [Thomas] is sharing his forklift design.

Now to scale up — maybe with DIY forklifts like we published earlier? We can see a lot of weary forklift drivers ready to kick back and let a robot have the full-time job for a change.

Continue reading “Mindstorms Forkliftbots Gonna Take Your Job”

3D Printed Hovercraft Takes to the Air

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

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

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

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”