Electric LEGO Longboard Now Complete with Epic Road Test

We recently posted about [James Bruton]’s most excellent oversized LEGO electric longboard. Well, now he has completed the project by tidying a few things and building oversized versions of classic light-up bricks to serve as headlamps and the tail light. Most importantly, he’s hitting the road with it!

He built a LEGO-looking enclosure for the battery as well, based on a 2×6 brick. The battery pack sits behind the motor with the tail light on top and holds the radio control receiver as well the twin LiPos. The head and tail lights pack 24-LED discs and are controlled by [James]’ FS-GT2B 3-channel RC transmitter. Its third channel is just a button, and he can trip that button to activate the lights with the help of a Turnigy receiver-controlled switch.

For an added touch he printed some LEGO flowers and a minifig, suitably oversized, and took the skateboard on the road. The thing has some zip! [James] kept his balance while holding the controller in one hand and a selfie stick with the other. The headlamp housings fell off, and a while later the minifig fell off. Fortunately [James] was able to snap them back into place, in proper LEGO fashion.

[James] runs XRobots and also served as a judge for the 2016 Hackaday Prize. We wrote up his Star Wars builds a while back, as well as his tutorial on mixed reality filming without a green screen.

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Monster Mindstorms Delta Bot Delicately Picks Candy

A group of embedded developers from Sioux Embedded Systems in Eindhoven, the Netherlands, wanted to get experience working on Microsoft .Net. To make it fun they made it their project to produce a LEGO train with visitors at LEGO World, the official LEGO convention in the Netherlands. The team developed an application in C# to fully automate the train, with Mindstorms NXT and EV3 bricks as well as LEGO Power Functions motors controlling everything.

The train project carries a simple premise: the visitor chooses one of four colors, and the train goes and picks up a piece of simulated candy with the matching color. Called Sioux.net on Track, the project has produced a new train every year since 2012 with improvement goals in place to add features with every version. Ironically, the least interesting part of the setup is the actual train and track. The team’s creativity comes to the fore in two areas of the project: the method by which the candy color is selected, and the assembly that dispenses the correct color into the train car.

Team member [Hans Odenthal] has built candy-grabbers for various years’ trains. He learned about the ABB FlexPicker and this year decided to build a delta robot for the layout. It consists of huge girders constructed from 5×9 and 5×11 Technic beam frames held together with more Technic beams and hundreds of connector pegs. The three arms each move on a pair of turntables which are geared down to provide as much torque as possible — the fake candy pieces are light, but the arms themselves weigh a lot. [Hans] ended up revamping the gearboxes to up the ratio from 1:5 to 1:25.

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Electric Skateboard Rocks the Giant LEGO

[James Bruton] built an electric skateboard out of oversized LEGO bricks he printed himself, and equipped the board with an excellent re-creation of a classic motor.

He began by downloading brick, gear, and pulley designs from Thingiverse and printing them up five times their normal size, taking 600 hours. The deck consists of 8M Technic bricks lengthwise and 4M bricks crosswise, with plates covering top. There’s even a monster 5×6 plate that’s clearly courtesy of a parametric brick design because you won’t find that configuration among LEGO’s official parts.

The coolest part of the project is probably [James]’ re-creation of an old school LEGO motor. He sized up a 6216M Technic motor originally rated for 4.5V swapping in a 1.5 kW, 24V motor controlled by a 120A ESC and powered pair of Turnigy 5000mAh LiPos wired in series.

[James] had to design his own casing in Blender because couldn’t find a file for the original LEGO part—pro tip for the future, LDraw has the 6216 design and it can be dropped into Blender.

Another nice touch are the wheels, with hubs based off upsized 40-tooth Technic gears with Ninjaflex tires that weigh half-a-kilo each and took 32 hours apiece to print.

We’ve published a lot of [James] ‘ work, including his BB-8 model and some of his other Star Wars models. Continue reading “Electric Skateboard Rocks the Giant LEGO”

Mindstorms Morse Key Writes to Drawbot

[Jason Allemann] built a Mindstorms Telegraph Machine that packs so many cool details that HaD is about to have a fit.

First off, It’s a drawbot able to write letters, a difficult feat given a lack of native stepper motors and the limited gear options for Mindstorms.  Trying to draw letters with servos typically makes for some ugly letters. And how does the drawbot know what to write? You code them in with Morse code. The second video after the break shows [Jason]’s setup. He has a Mindstorms touch sensor with a LEGO Morse key attached to it. He simply taps on the key and the EV3 Intelligent Brick interprets his dots and dashes and translates them into letters.

Next off, [Jason]’s printer is built using one EV3 set. It’s one thing to build a cool Mindstorms robot with whatever you have in your parts bin, but the gold standard is to make a project that can be built with only one EV3 set. That way, anyone with the set can build the project. Precious few really cool projects can be built with just one set–[David Gilday]’s MindCub3r Rubik’s cube solver comes to mind. Dude, this is another one.

Last off, [Jason] breaks down how to build it, providing full LDraw building steps and EV3 code on his site. Even better, he shows how to supersize the project by adding a second EV3 brick, which can connect to the drawbot’s EV3 brick via bluetooth and serve as a standalone CW key. He shows off this part in the second video.

Icing on the cake, [Jason] even built a Morse reference book, done appropriately in 100% LEGO.

Hackaday loves innovative LEGO projects, like this game-playing robot and this LEGO exoskeleton.

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We Dig This LEGO Excavator Conversion

[Frank] was lucky enough to score a bucket wheel excavator LEGO set as a birthday present, and we won’t lie – we’re jealous. However, out of the box, the kit is somewhat limited; there is only one motor to animate the entire machine and it can’t be fully remote controlled. But don’t worry — [Frank] set out to change that (Google Translation).

The first part of the build was to add motors to control the different functions of the excavator. One motor was added for each of the two tracks to allow the machine to drive forwards, backwards, and turn. Two more motors were added to raise and lower the digging buckets, and spin the tower. Finally, the original motor was left in place to turn the conveyor.

With that done, [Frank] then used a Raspberry Pi 3 to control all the hardware, being sure to house the new electronics in LEGO for an original look. The Raspberry Pi might be a lot of muscle to simply control a few motors, but it made it quick and easy for [Frank] to implement a Wiimote as a controller over Bluetooth. You can check out a couple demo videos in his most recent update.

It’s a great project, and we’d love to see the Raspberry Pi put to good use by allowing control over the Internet so we can dig in the sand over lunch breaks. We’ve seen some great LEGO hacks before, like this method of modifying cheap gear motors to work with LEGO parts.

Making Spirographs with LEGO and Math

Master LEGO builder [Yoshihito Isogawa] has been on a roll lately, cranking out a number of robots that make drawings reminiscent of the classic Spirograph toy. For instance, he built an elegant drawbot out of LEGO elements, seen above. At first glance the monicker “spirograph” seems wrong, because where are the gears? However, [Yoshihito] has them stashed underneath the sheet of paper, with magnets controlling the pens.

His drawbot consists of a platform (cleverly, an inverted LEGO plate) upon which a sheet of paper is laid. One or two pen holders, each with a pair of magnets underneath, rest on the sheet of paper. Beneath the plate, two pairs of spinning magnets rotate around a double layer of 11×11 curved racks, which then play the role of the classic spirograph rings. An EV3-controlled motor powers the whole thing.

He also makes use of an obscure part–the 14-tooth bevel gear, last manufactured by LEGO in 2002 and even then it was mostly sold in part assortments intended for the education market. It’s so obscure LEGO doesn’t even provide the gear in their online building program LEGO Digital Designer, though (of course) the LDraw folks re-created it — it’s brick 4143 in the library, seen below.

Spirograph Gear Math

This gear becomes important in spirograph-style projects because tooth count is everything. There really aren’t that many spirograph designs that can be made with LEGO, because there are a limited number of gears and they mostly have the same tooth counts–the smaller ones sport 8, 12, or 16 teeth, medium-sized ones 20 or 24 teeth, and larger ones 36 or 40 — see a pattern? Such predictability may be great for a building set, but it doesn’t engender a lot of spirograph diversity.

When you compute the number of vertices in a spirograph shape, you take the least common multiple of the two gears (or sets of gears) and divide by the small gear. So a 60-tooth turntable turning a pair of 14-tooth gears has an LCM of 420, and you divide by 28 to get the number of vertices: 15. Remove one of those smaller gears and the vertices increase to 30. The challenge in creating new shapes with a LEGO spirograph lays in swapping in new gears, just like the original toy, and having more ways to come up with unusual gear ratios makes for more interesting drawings.

Another that makes the 14-tooth gear so alluring to [Yoshihito] is that it’s one of the few LEGO gears with a number of teeth not divisible by 4. Among other things this means the gear meshes with an identical gear at 90 degrees. Usually the gears have the same number for each quarter of the circumference and meshing becomes a matter of jogging one gear a scosh. This can be a problem because LEGO axles have a “plus” shaped profile, and you may not want everything on that axle tilted as well — having a 90-degree solution makes a lot of sense.

[Yoshihito] designs LEGO robots out of Isogawa Studio and has written several books on advanced LEGO techniques, published by No Starch. He specializes in small and elegant mechanisms — finding the perfect set of elements that work together effortlessly. You can see an example in the gear assembly to the right — a pair of the aforementioned 14-tooth bevel gears, turned into a normal gear with the help of that golden spacer, none other than a One Ring from LEGO’s Lord of the Rings product line. You can find videos of his projects on YouTube.

[Yoshihito] has released a number of variants of the spirographing drawbot. What’s next? Maybe a harmonograph?

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EV3DEV Lego Linux Updated

The ev3dev Linux distribution got an update this month. The distribution targets the Lego EV3 which is a CPU Lego provides to drive their Mindstorm robots. The new release includes the most recent kernel and updates from Debian 8.8. It also contains tools needed for some Wi-Fi dongles and other updates.

If you haven’t seen ev3dev before, it is quite simply Linux that boots on the EV3 hardware using an SD card. You don’t have to reflash the computer and if you want to return to stock, just take out the SD card. You can also use ev3dev on a Raspberry Pi or BeagleBone, if you like. There’s a driver framework included for handling sensors, motors, and other items using the file system.

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