Misc Hacks

4177 Articles

Bitten By PCB Defects

May 5, 2015 by 54 Comments

If you’ve ordered PCBs from Seeed Studio, ITead, DirtyPCB, or another board house in China, you’ve probably noticed that neat little 100% e-test option available on the order form. If you select this, the board house will throw your PCBs in a machine that will poke a pin in every pad to make sure all the connections are good. Less work for you, right? As [Andy] found out, not always. He was bitten by a manufacturing defect that sheds some light on what that e-test actually is, and the capabilities of what these Chinese board houses can do.

Most of [Andy]’s project have a lot of surface mount components, and when he receives his boards, he notices a few pin pricks on each and every pad. This is from a flying lead machine; a robotic continuity checker that makes sure all the relevant pads are electrically isolated from each other.

One of [Andy]’s recent projects is an entirely through-hole design. Apparently these robotic meters don’t test through-hole pads; it’s significantly harder to measure the continuity of a hole rather than a pad, apparently. After assembling one of these boards, he noticed a problem where one of the GPIOs was permanently high. The offending trace was found underneath a DIP socket, in precisely the worst possible place it could be.

If [Andy] had inspected the board beforehand, this problem would have been avoided. He says it was a relatively simple board with big traces and wide spaces and he didn’t think a manufacturing defect was possible. He was wrong, and now we have a warning. We thank him for that.

Trademarking Makerspace

May 5, 2015 by 89 Comments

UnternehmerTUMMakerSpaceGmbH, a tech accelerator in Munich, Germany, has just filed an application to trademark the word Makerspace. This has caused some contention in the German-speaking hackosphere, and if this trademark application is approved, the few spaces in Germany that identify as a makerspace may soon be changing the sign out front.

It must be noted this trademark application only covers the word ‘Makerspace’, and not “Hackerspace”. To most of the population, the word ‘hacker’ – in English and German – conjures up images of someone wearing a balaclava and using a laptop to steal bank accounts. To the uninitiated public, a hackerspace is distinct from a makerspace. In reality, they are remarkably similar: a hackerspace has a room filled with tools; a makerspace has a room filled with tools that allow people to control their language. Little difference, really, if you discount the [Frank Luntz]-level wordsmithing.

While this could go badly for any ~space in Germany with a ‘maker’ prefix, trademarking ‘makerspace’ isn’t really that much different from calling it a TechShop, and the trademark application is probably just a product of lawyers. In any event, it looks like  UnternehmerTUM MakerSpace GmbH has a pretty cool space; 1500m² (16000sq ft) of space, a water jet, and even some sewing equipment. We’d be happy to take a tour, so long as they don’t enforce the trademark.

Thanks [Moritz] for the tip.

Decoding And Replicating Xantrex Solar Charge Data

May 3, 2015 by 13 Comments

This is a story mostly of decoding data, but there is a happy ending that includes turning that decoding work into an open source receiver. Xantrex solar charge controllers monitor a lot of data about what is happening with your solar panels, and they stream it over RJ25 but you need their add-on hardware to receive it. [Eric Herbers] figured if the data is being transmitted, a resourceful hackers should be able to decode it. And he did just that with a little help from his friends in the Hackaday community.

We asked on Twitter what people were working on and [Eric] posted his scope screenshot. The conversation that followed helped point him in the right direction and others knowing about the project surely drove him to finish it. The decoding isn’t perfect, but achieve enough to decode and display voltage, amperage, and temperature. [Eric] built the display unit using an Arduino Pro Mini and a character LCD housed in you most common of black project boxes.

Strong Little Robots With Gecko Technology

April 30, 2015 by 29 Comments

If you need to build a robot to carry something, you need a bit motor, right? Not so with these tiny robots out of Stanford’s Biomimetic Dexterous Manipulation Laboratory. One of these 12g MicroTugs can drag a 600g mug of coffee across a table, or even a 12kg weight. According to the authors, it’s a, ‘capability … comparable to a human dragging a blue whale.’ Square-cube law notwithstanding, of course.

What makes these little robots so strong? It’s not the actuators; it’s their feet. On the bottom of this robot is a material that uses mechanical anisotropic adhesion, a fancy material that only sticks to flat surfaces when it’s being pulled in a specific direction.

The best description of this material inspired by gecko feet would be this video, also from the Stanford BDML lab. It’s a neat material that we’ll probably find in Post-It notes in a decade, and with a single motor, a tiny robot can lift thousands of times its own body weight.

Videos below. Thanks [Adrian] for the tip.

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A Scary Powerful Jacob’s Ladder

April 20, 2015 by 22 Comments

What to do with an extremely high voltage transformer and power supply… what to do…  what to do… Short it out Jacob’s Ladder style of course! Fresh from [Gristronics], a team of hackers had the opportunity to play around with a 11,000V transformer… and some copper pipe.

It’s 2.5m tall (just over 8′) and produces an awe-inspiring electrical arc. The transformer takes in 240V and spits out 11,000V. To help stabilize it, they’re even using some microwave oven capacitors to act as a ballast. The transformer is affectionately named “Betsy”. They even have a giant contactor (think relay with steroids) to act as the main switch.

During the initial setup, they noticed it wasn’t working very well, so they setup a camera to record at 240fps to see what was going on — turns out the coils were shorting to each other. After fixing the insulation, they got it working consistently — and holy cow is that a big arc.

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Paper Topo Models With Vector Cutter

April 18, 2015 by 18 Comments

If there’s a science fair coming up, this trumps just about any 2D poster. It’s a 3D topographical map of an inactive Slovakian volcano, Poľana. [Peter Vojtek] came up an easy way to generate SVG topo patterns using Ruby.

Topographical data is available through the MapQuest API. You should be able to model just about any part of the world, but areas with the greatest elevation difference are going to yield the most interesting results. The work starts by defining a rectangular area using map coordinates and deciding the number of steps (sheets of paper representing this rectangle). The data are then chopped up into tables for each slice, converted to SVG points, and a file is spit out for the blade cutting machine. Of course you could up the game and laser cut these from more substantial stock. If you have tips for laser-cutting paper without singing the edges let us know. We’ve mostly seen failure when trying that.

The red model explained in [Peter’s] writeup uses small cross-pieces to hold the slices. We like the look of the Blue model which incorporates those crosses in the elevation representation. He doesn’t explain that specifically but it should be easy to figure out — rotate the rectangle and perform the slicing a second time, right?

If you’re looking for more fun with topography we’ve always been fond of [Caroline’s] bathymetric book.

You Betta’ Recognize The Aluminum Beverage Can

April 17, 2015 by 27 Comments

He’s back, [Bill Hammack] aka The Engineer Guy. He has a habit of revealing how the ordinary is extraordinary with a meticulous unveiling of all the engineering that goes into a thing. This time around it’s the aluminum beverage can. You might know it as a soda can, a beer can, or a salt-free air can. But we challenge you find someone who isn’t intimately familiar with these containers.

We know what you’re thinking: you already saw how these come into being on an episode of How It’s Made. You’re wrong. We saw that episode too. But just give [Bill] a few minutes of your time and he’ll suck you in for the rest of the episode. Now the die-forming of the base and side-wall, we’ll give it to you that you know what that’s all about. But then [Bill] busts into the history of these containers, citing the aluminum savings through reducing the top diameter of the can. He rounds it out with a celebration of the ingenuity of the modern “stay-on” tab which should make your glasses fall off with excitement.

If this is your first time hearing of The Engineer Guy you have a delightful weekend ahead of you. Binge watch his entire back cataolog! Our favorites include an analysis of a mechanical Fourier computer and the concepts involved in color anodization. We even read his book.

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