Simplest Jumping Kangaroo Bot

One of the takeaway ideas that we got from BEAM robotics was the idea that the machine itself, rather than tons of processing power, can do a lot. Your hand affords gripping, and humans have made a pretty good living out of manipulating things (he says, typing). None of this is about the brain; it’s all about the mechanism.

Which brings us to the one-motor “Runner” robot. We’ll admit that we were a little bit disappointed to see that it doesn’t run so much as hop, flop, or scoot along on the two legs and that front wheel-nose. Still, it’s an awesome mechanism, and gets the locomotion job done in a very theatrical way. We’re left wondering if using two motors would allow it to steer or just flip over and flail around on its back. Going to a six “leg” design will definitely get the job done, as demonstrated by Boston Dynamics RHex robot.
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From Shop Floor Dust To Carbon Steel

[Chandler Dickinson] did his monthly sweep of the floor in his blacksmith’s shop when it occurred to him that all that metal dust had to go somewhere, didn’t it? So he did the only reasonable thing and made a crude foundry out of cinder blocks, melted his dirt in it, and examined what came out the other end.

His first step was to “pan” for steel. He rinsed all the dirt in a bucket of water and then ran a magnet at the bottom of the bucket. The material that stuck to the magnet, was ripe for reclaimation.

Next he spent a few hours charging a cinderblock foundry with coal and his iron dust. The cinderblocks cracked from the heat, but at the end he had a few very ugly brittle rocks that stuck to a magnet.

Of course there’s a solution to this non-homogenous steel. As every culture with crappy steel eventually discovered, you can get really good steel if you just fold it over and over again.  So he spend some time hammering one of his ugly rocks and folding it a bit. He didn’t get to two hundred folds, but it was enough to show that the resulting slag was indeed usable iron.

He did a deeper examination of the steel last week, going as far as to etch it, after discovering that the metal sparked completely differently when sanded on one side versus the other. It definitely needed work, but all seemed to have worked in the end.

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Hacklet 108 – Simple Functional 3D Prints

We featured 3D printer projects on last week’s Hacklet. This week, we’re looking at a few awesome projects created with those printers. Trying to pick great 3D printed projects on is a bit like staring at the sun. There are just way too many to choose from. To make things a bit easier, I’ve broken things down into categories. There are artistic prints, complex mechanical or electronic prints, and then there are simple functional prints, which is the topic we’re featuring today. Simple functional prints are designs which perform some function in the world. By simple, I mean they have only a few moving parts or electronic components. Let’s get right to it!

cornersWe start with [Scott] and L Extrusion Endcaps. Every Home Depot, Lowes, or hardware store has a selection of extruded aluminum. Typically there are a few flat bars, and some L brackets. L brackets are great, but they can be a pain to work with. Most of us don’t have the skills or the tools to weld aluminum, so nuts and bolts are the only way to go. [Scott’s] given us another option. He’s designed a set of 3D printable brackets that slip onto the ends of the brackets. The brackets make quick work of building boxes, racks, or anything with 90° or 45° angles.


earbudNext up is [Joe M] with 3D Printed Molds: Custom Silicone Earbuds. [Joe] had a set of Bluetooth earbuds he enjoyed, but the rubber tips left a bit to be desired. Not a problem when you have a 3D printer on hand. [Joe] measured the plastic part of his earbuds and the rubber tips from a different set he liked. A bit of CAD magic later, and he had a model for the perfect earbud tip. While he could have directly printed the tip in a flexible filament like NinjaFlex, [Joe] opted for a pure silicone tip. He printed molds, then mixed silicone caulk with cornstarch (as a catalyst). The resulting earbuds sound and feel great!

coil2Next we have [Jetty] with Highly Configurable 3D Printed Helmholtz Coil. Helmholtz coils are used to create uniform magnetic fields. Why would you want to do that? It could be anything from measuring magnets to cancelling out the effect of the earth’s magnetic field on a device being tested. [Jetty’s] wrote an OpenScad program which allows the user to enter parameters for their coil. [Jetty’s] program then calculates the coil’s magnetic properties, and outputs a printable .stl file. Building the coil is as simple as printing it and wrapping some copper wire. [Jetty] found that his coil was within 60nT (nanoTesla) of the expected value. Not bad for a bit of plastic and wire!


scope1Finally we have StickScope,  [SUF’s] entry in the 2016 Hackaday Prize. Like many of us, [SUF] loves his StickVise. Sometimes you need a bit of magnification to see those tiny 0201 resistors though. [SUF] had a cheap USB microscope on hand, so he designed StickScope, a USB microscope mount designed especially for the StickVise. Two 6mm steel rods are the backbone of the design. 3D printed clamps hold the system together like a miniature boom microscope. This is actually the third revision of the design. [SUF] found that the original design couldn’t be used with parts close to the bar which holds the microscope. A small jaw extender was the perfect tweak.


If you want to see more simple functional 3D printed projects, check out our new simple functional 3D prints list! If I missed your project, don’t be shy, just drop me a message on That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of!

Robo-Wire-Snips Clip 1k Segments

Quick, you need 1000 pieces of wire of the same length, what do you do? The disappointing answer is to put on the miniseries masterpiece Frank Herbert’s Dune and get to work snipping those bits by hand. We usually clamp a scrap piece of molding protruding perpendicular to the bench to use as a length guide in these cases.

The more exciting answer is to build a robot to do it for you. There’s no way you can build the robot faster than you could cut the wire… unless you have admirable rapid prototyping skills like [Eberhard]. He strapped together a barebones machine from two motors, and one switch in no time. Pretty amazing!

Wire coming off the spool feeds through two guides held by a third-hand. The outfeed length depends entirely on timing; two slices of wine cork drive the wire which passes through the open jaws of a wire snip. Those snips are hot-glued in place, with a motor winding up a strip connected to the other handle in order to make the cut. The only feedback is a limit switch when the snip is fully open.

It is entirely possible to get even less advanced. Here’s the same concept without the limiting switch. We appreciate the eloquence of the snipper squeeze method on that one. But for the most part we think you’ll be interested in one that goes about stripping the wire ends as well as cutting to length.

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Simple and Elegant Single Digit Nixie Tube Clock

We’ve seen a few Nixie projects around here before, but this one might be the simplest yet. [Pinomelean] designed this simple nixie tube clock with just a handful of components.

The Nixie tube chosen for the project is an IN-12a. This tube can be purchased for around just four dollars. It is capable of displaying one digit at a time, zero through nine. Since the tube can only display one digit at a time, the clock is programmed to flash each digit of the current time one by one. There is a longer pause in between each cycle to make it easier to tell when the cycle begins and ends.

The system is broken into two main components. The first is the clock circuit. The clock runs off a PIC microcontroller with a 4MHz crystal. All of the logic is performed via the PIC and only a handful of other components are required. This includes some resistors and capacitors as well as a few high voltage SMD transistors to control the Nixie tube. [Pinomelean] has made this PCB design available so anyone can download it and make their own clock.

The second component to the clock is the power supply. The system is powered by a lithium-ion rechargeable battery, but [Pinomelean] notes that it can also be powered with USB. The lower voltage works well for the microcontroller, but the Nixie tube needs a higher voltage. [Pinomelean] built his own high voltage supply using components scavenged from an old disposable camera. This power supply board design is also made available for download, but it plugs into the main board so you can use another design if desired.. Check out the demo video below to see it in action. Continue reading “Simple and Elegant Single Digit Nixie Tube Clock”

Electronic dice, overkill and simplified

[littlebird] posted a tutorial on making electronic dice.  He’s using an ATmega328 for the numbers work, and a mercury switch to activate it all. A nice blue enclosure to match the blue LEDs he’s using for the number display wraps it up nicely. Of course, someone had to mention that this was an amazing amount of over kill and it could just be done with a 555 timer like they used to do “back in the day”. [littlebird] responded with another tutorial to prove that he hadn’t forgotten how to work with the basics. He goes on to point out, now that we see both in action, that he can expand his microcontroller based one quickly with a few lines of code, where every new feature added to the 555 timer version would require additional components.

You can catch videos of both after the break.

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A fantastic collection of slapped together bots

[David Williamson] has put together some pretty amazing little robots from bits of stuff he laying around the house. What initially caught our attention was this drawing robot over at HackedGadgets. We were impressed by the construction, as it looks like almost all of it was scrap. Upon clicking through the link we found a small collection that kept as amused for quite a while. Each one has some aspect that is surprising in its use of mundane materials. Need an omniwheel? Why not use plastic beads. Want a rail from which a robot can hang and drive? why not use drinking straws. Many of them may not have much for a brain, but the construction of the mechanisms is usually pretty interesting alone. You can see clips of some of his creations in the video after the break.

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