Eddie The Balance Bot

May 10, 2016 by Gerrit Coetzee 15 Comments

Eddie is a surprisingly capable tiny balancing robot based around the Intel Edison from which it takes its name.

Eddie’s frame is 3D printed and comes in camera and top hat editions. The camera edition provides space for a webcam to be mounted, since the Edison has enough go power to do basic vision. The top hat edition just lets you 3D print a tiny top hat for the robot.

The electronics are based around the Edison board and Sparkfun’s set of, “Blocks” designed for it. This project needs the battery block, the H-Bridge block, the GPIO block, and the USB block along with a 9DOF block for balancing. It’s, somewhat unfortunately, not a cheap robot. The motors are Pololu all-metal gearmotors with hall-effect sensors acting as encoders.

We’re really impressed with [diabetemonster]’s design and documentation on the robot. Full source code is provided along with a very nice build guide to get the platform going fast.

There are a few videos of it in action, available after the break. They show it handling situation such as a load being placed on the robot and slopes as well as bonus features like dancing and remote control.

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Don’t Ignore The Artist’s Supply Store

May 10, 2016 by Gerrit Coetzee 49 Comments

So it’s Saturday morning and you’ve found yourself with an urge to build something involving copper plates or carbon electrodes. Maybe you need a metallic powder for a chemistry experiment. Casting supplies? Pure lead? Copper mesh? Silver wire? Odd tools? Exceedingly caustic etchants? There’s a store that sells it all, and it’s not usually frequented by hackers: the art store.

If you know where to look, the store is full of useful things. Each method of expression in art has its own set of supplies; a bountiful collection of various processes and the useful things therein. I grew up in a city that did not have a real art supply store. It had one of those big box craft stores that assault you with glittery plasticized flowers and terrible manufactured scents. When I moved to a different city and walked over to the local art supply to purchase some new pens I ended up staying for a few hours just looking at all the cool things they had for sale.

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Glue Your Sumo Robot To The Mat With Custom Sticky Tires

May 9, 2016 by Gerrit Coetzee 7 Comments

Mini Sumo seems like one of those hobbies that starts out innocently enough, and ends up with a special room in the house dedicated to it. One day you’re excitedly opening up your first Basic Stamp kit, and the next you’re milling out mini molds on a mini lathe to make mini extra sticky tires.

[Dave] started out trying to find a part from the local big box store that was just a little bigger than the wheel he wanted to rubberize. He set the wheel inside a plumbing cap and poured the urethane in. It worked, but it required a lot of time with a sharp knife to carve away the excess rubber.

In the meantime he acquired a Sherline Mini Mill and Lathe. With the new tools available to him, he made a new mold out of a bit of purple UHMW and some acrylic. This one produced much nicer results. Using a syringe he squeezed resin into the mold through a hole in the acrylic. Much less cleanup was needed.

He later applied these methods to smaller, wider wheels as his mini sumo addiction took a stronger hold on his life.

DIY Cast AR-15 Receivers Are More Interesting Than Expected

May 8, 2016 by Gerrit Coetzee 193 Comments

For some reason the US News media decided on the AR-15 as the poster child of guns that should not be allowed to be made for, or sold to, the consumer. The words still out on the regulation, but, in a very American response, a whole market sprang up around people saying, “Well, then we’ll just make our own AR-15.”

Ordinarily, we wouldn’t cover this sort of thing, but the work [AR-15Mold] is doing is just so dang interesting. They sell a product that enables the home user to cast an AR-15 receiver out of high performance resin. In the process they made a really informative three part video on the casting process.

A lot of people are interested in the product, and having fun with it. In this two part video series, [Liberty Marksman] cast their receivers and test them to destruction. In one video they see how many rounds they can fire out of the gun before it breaks. When it breaks, they excitedly tear down the gun to see where it failed.

It’s quite a bit of fun to watch. Videos after the break.

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Tiling Your TV Remote

May 8, 2016 by Gerrit Coetzee 35 Comments

The Tile is a small Bluetooth chip, speaker, and enough battery for a year in a keychain format. If you lose your keys in the morning, simply use the app on your phone to find the keychain. If you lose your phone simply get out your second phone.

This planned obsolescence didn’t jive with [JM] when his Tile stopped being discoverable. He didn’t want to toss a gadget that had served him so well into the landfill. So, like any good hacker, he cracked its plastic case open.

The Tile itself is a really interesting product. The largest component is the battery which has tabs spot-welded to its surface. Attached to those is a well laid out board. [JM] points out the clever use of spring contacts to engage the piezo element for the speaker as a nice example of good design for manufacture.

The hack itself was pretty easy to complete. Some electrical tape and soldering was all it took to embed the tile into the remote. Now he can take out his phone and press a button to hear a forlorn beep coming from under the couch cushions.

Fallout Inspired Cellphone Wristwatch

May 6, 2016 by Gerrit Coetzee 13 Comments

[Mr. Volt] mentions that some of the commenters on his videos believed that he shouldn’t be making large, retro computer themed communicator watches. He believes they are wrong, naturally we are compelled to agree with him.

In his latest build he has produced a rather well-built and large cell-phone watch. After the untimely death of an Apple II cellphone watch, he decided to up his game and make one that could take more of a beating. The case is 3D printed, which is hard to believe given the good finish. He must have spent a long time sanding the prints. Some wood veneer for looks and aluminum panels for strength complete the assembly.

The electronics are a Teensy and a GSM module. It looks like he places calls by calling the operator since the wrist communicator only has four inputs: a red button, a blue button, and a momentary switch rotary encoder.

The communicator appears to work really smoothly, and it would certainly draw attention to him were he to wear it anywhere other than the Wasteland. Video after the break.

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Up Your CAD Game With Good Reference Photos

May 6, 2016 by Gerrit Coetzee 28 Comments

I’ve taken lots of reference photos for various projects. The first time, I remember suffering a lot and having to redo a model a few times before I got a picture that worked. Just like measuring parts badly, refining your reference photo skills will save you a lot of time and effort when trying to reproduce objects in CAD. Once you have a model of an object, it’s easy to design mating parts, to reproduce the original, or even for milling the original for precise alterations.

I’m adding some parts onto a cheap food dehydrator from the local import store. I’m not certain if my project will succeed, but it’s a good project to talk about taking reference photos. The object is white, indistinct, and awkward, which makes it a difficult object to take a good photo for reference use in a CAD program. I looked around for a decent tutorial on the subject, and only found one. Maybe my Google-fu wasn’t the best that day. Either way, It was mostly for taking good orthogonal shots, and not how to optimize the picture to get dimensions out of it later.

There are a few things to note when taking a reference photo. The first is the distortion and the setup of your equipment to combat it. The second is including reference scales and surfaces to assist in producing a final model from which geometry and dimensions can be accurately taken. The last is post-processing the picture to try to fight the distortion, and also to prepare it for use in cad and modeling software.

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