Jared Holladay

The Safest Model Roller Coaster

[Jared Holladay] is a computer engineering student at the University of Cincinnati and a life-long roller coaster fanatic. A lot of people look at roller coasters as an exciting example of physics, like potential energy versus kinetic energy or inertia, and rightly so. [Jared] looks at them and wonders about the controls. Video also below and there is a feature-length explanation with more details. Some Hackaday readers and writers can identify the components, so we think his coaster model belongs here.

Like many folks in this field, he’s built K’nex models to get a handle on construction. He’s toured STEM shows with the tracks and undoubtedly wowed kids, adults, and physics teachers, but since he can speak to the programming, he is a triple threat. Now, he’s growing out of the toy construction plastic and moving into 3D printed parts with needle-fine tolerances.

His latest base is extruded aluminum, like what you’d want in a rigid CNC or printer. In addition to the industrial-grade surface, Rockwell Automation sent him a safety programmable logic controller, PLC, and a touchscreen HMI. Our fellows in the industry tell us those are far beyond the price scope of regular hobbyists. But fear not; your Arduino clones will suffice until you get your first grant.

The point of all the ruggedized hardware, aside from authenticity, is to implement safety features the same way you would in the industry. The redundant PLC connects to inductive prox sensors to check train speed and location. Other moving parts, like friction brakes, have sensors to report if there is a jam. After all, it’s no good if you can’t stop a train full of people. There are hundreds of things that can go wrong. Just ask [Jared] because he programmed on-screen indicators for all of them and classified them to let an operator know if they can keep the ride moving or if they need to call maintenance.

Not all homemade coasters are scale models, and some of the traditional ones have more than meets the eye.

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Dublin Knows How To Bring-a-Hack

When on the road, we love to stop by a local hackerspace and connect with the hacker community. On Friday, TOG Hackerspace in Dublin, Ireland opened their doors to host a Bring-a-Hack with Hackaday and Tindie.

The city center of Dublin is anything but a grid. The cobblestone roads meander every which way and are a puzzle of one-way and surprise construction, none of which seemed to faze Google’s navigation algorithms. I was happy to be operating the smartphone instead of the rental vehicle. A big thanks goes to Jenny List for taking on the stress of driving on our refreshments run without coming in contact with people or cars.

You’re likely wondering why the street layout of the city deserves such attention. I’m used to centrally-located Hackerspaces being tight on space, and indeed the members of TOG cautioned us that 50 people would feel cramped. Much the opposite, the pubs, restaurants, hotels, and performing arts centers are not small, nor winding, nor made of cobblestones. Dublin is a fantastic place to party, with plenty of space for us hardware geeks to congregate. TOG itself, which about 20 minutes walk from the central Temple Bar area (where this image was taken), even has a small parking lot which made our beer drop off and pizza delivery a breeze.

A Tour of TOG Hackerspace

TOG is a Gaelic word which loosely translates as “to make”. Declan met us for the beer drop and gave us a tour when we returned for the evening event. The building is divided into several different spaces, starting with an entry area that serves as a meeting space, gaming room, and showcase of projects.

Where you might see prayer flags strung up on an apartment building, we see floppy disks (both the hard and soft variety) strung around the meeting area. Declan has a shamrock of K’nex parts wired up with a microphone controlled RGB LED strip — it’s like a test your strength game to see who can shout the coolest colors.

I also really enjoyed the fabric anatomy display that has snaps on each organ and only lights up the labels if you complete the circuits in the correct locations.

These are just the tip of the iceberg. There’s much more after the break so join me for the rest of the tour, and some of the notable hacks that showed up on Friday evening.

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Enlarged Miniature Forklift

How do you classify something that is gigantic and miniature at the same time? LEGO kit 850, from 1977 when it was known as an Expert Builder set, was 210 modular blocks meant to be transformed into a forklift nearly 140mm tall. [Matt Denton] scaled up the miniature pieces but it still produced a smaller-than-life forklift. This is somewhere in the creamy middle because his eight-year-old nephew can sit on it but most adults would demolish their self-esteem if they attempted the same feat.

[Matt] has been seen before building these modular sets from enlarged LEGO blocks, like his Quintuple-Sized Go-Kart. He seems to have chosen the same scale for the pieces and who wouldn’t? If you’re printing yourself a ton of LEGO blocks, it just makes sense to keep them all compatible. Isn’t combing all your sets into one mishmash the point after all? We’ll see what his nephew/co-host constructs after his uncle [Matt] leaves.

In the time-lapse video after the break, you can see how the kit goes together as easily as you would hope from home-made bricks. With that kind of repeatability and a second successful project, it’s safe to say his technique is solid and this opens the door to over-sized projects to which LEGO hasn’t published instructions.

Hackaday is bursting with LEGO projects, K’Nex projects, and even Erector set projects.

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I’ve Seen The Future And It’s Full Of Freakin’ Huge Bricks

“Did you know you can 3D-print LEGO bricks that can actually be used as regular LEGO?”–me, in 2009

Those magical words made real to me the wonder that was 3D printing. It was a magical time! Everyone was 3D printing everything, though most of it wasn’t very good because the technology wasn’t there. But just as every technology goes through an evolution, the goalposts of coolness move on past what used to be remarkable to the new thing everyone’s talking about.

These days, no one is going to be more than mildly curious about your 3D-printed LEGO brick. Still, when you look at that uneven lump of plastic as being just one step in an evolution, it’s pretty momentous. What I’m saying is that we’re looking at a future that can be described in three words: Freakin’ Huge Bricks.

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Make A Tesla Coil Winding Rig With K’Nex

Instructables user [birdycrazy] built a winding rig from a PVC pipe and a bunch of K’Nex. He had recently started a Tesla coil project and needed an efficient way to wind the secondary coil. All of the designs for DIY winding rigs he found on the Internet required parts he didn’t have or simply cost a bunch of money. Then he realized he’d been building with K’nex a lot, and why not build a tool to help him?

He ended up investing only his K’nex elements and a length of 4” PVC pipe for the project. He used a K’nex 12V motor because it plugs in rather than requiring batteries. After the coil had been completely wound he set it to rotate the assembly over a period of several days while the varnish coating dried.

[birdycrazy] has several cool K’nex projects including a couple of automatic transmissions and a differential, all made with the toy. Also be sure to check out the K’nex whiteboard plotter, the Citadel monster K’nex castle, and the K’nex skeeball table we published in the past.

Join Us At The Greatest 3D Printing Festival On Planet Earth

Winter is hanging on like clinical depression, which means it’s that time again for the greatest 3D-printing festival on the planet Earth. It’s time for the Midwest RepRap Festival, next weekend, March 18-20th in Goshen, Indiana.

I can’t explain why, but for some reason the Midwest RepRap Festival is an oasis of building, doing, and hacking right in the middle of the county fairgrounds for Elkhart County, Indiana. It’s free for everyone to attend. The event isn’t choked with vendors, leaving the people who actually do stuff left to fight over a few picnic tables on the outskirts of the venue. It is, by far, the most community-centered event we go to every year.

If you’re wondering what you can expect at a 3D printer convention in the middle of nowhere, check out a few of the posts we’ve published from MRRF over the last few years. We’ve seen 3D printed waffles, resin casting with 3D printed molds, bizarre movement platforms, Bioprinting, and stuff from Lulzbot. That’s just the stuff that has deserved its own Hackaday post: we’ve seen the world’s largest 3D printed trash can, R2D2, battle droids (it’s even money if BB-8 is going to show up this year), a Printer made out of K’nex, and the most beautiful 3D printer we’ve ever seen. There was a T-shirt cannon powered by 300 psi shop air.

Every year I write a post announcing that we’ll be heading to MRRF next week, simultaneously praising the event as one of the greatest ‘maker’ and ‘DIY’ meetups, while pointing out the local WalMart parking lot has a place to park horse-drawn buggies. Both observations are true. For one weekend a year, Goshen, Indiana is the place everyone reading Hackaday should go to, and that is why we are once again proud to sponsor this glorious event.

3D Cable Robot Uses The Building As Its Exoskeleton.

There’s not much information about this commercial product, but it looks so interesting, we just had to share it. It doesn’t seem there is anything too magical happening here: some motors (presumably some type of servo or stepper with positioning feedback) some cables and pulleys, and an end effector of your choosing. Oh, and just some clever math to solve the inverse kinematics – not that inverse kinematics is all that easy! You can see the robot at work in the video after the break.

Most likely you’ve already seen the end results of such a three-dimensional cable driven system on your TV. If you’re a fan of most field sports, the SkyCam system is what’s used to deliver the stunning aerial shots that really put you into the game. We’ve covered this sort of mechanism before, but only in two dimensions. Usually we see the concept used as a white-board plotter like this extremely methodical Polargraph or one built with K’NEX.

We can’t help but wonder how this might be adapted into other situations?  Perhaps, you could use small light-weight cables (fishing line) and pulleys to make a living-room beer delivery system or TV remote retrieval claw?  Or could it become the mechanics of a really large format 3D printer? If any of you do rig up some sort of house-hold beverage fetching robot, be sure to let us know via the tipline.

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