Itsy Bitsy Teenie Weenie 3D Printed RC Truck

October 17, 2015 by George Graves 26 Comments

I think it’s safe to say that almost all of us grew up playing with toy cars. They were cheap, and darn near indestructible. Some went by the brand name of “Hot Wheels”, and others “Matchbox”. As a kid, you most likely spent many an hour on the floor imagining your “toy” to be a real car – and of course, adding the all important sound effects. Vroom-vroommmmm!

Flash forward to 2015, and see how things have changed. There are several “micro” RC cars and trucks on the market you can buy for about $10, but this is the first micro-sized, DIY, 3D printed, 4×4 truck we’ve seen. And to add to that, it even has a working articulated front end loader.

Coming in at a minute 1/87th scale, this tiny truck and matching controller boasts 6 channels, 4-wheel drive, and a working trailer hitch. In the video after the break, you can see the amazing amount of work that [Mortimer] had to put into this build to get everything to fit in such a small space. Although the video is German, we think it’s fairly easy to see what’s going on. [Mortimer] is sharing the 3D printed files on his Shapeways page if you would like to give this build a go.

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Thor’s Hammer Build Recognizes Its Master’s Hand

October 14, 2015 by Mike Szczys 52 Comments

Only those who have completely insulated themselves from modern pop culture will miss the meaning of a Mjolnir build. It is, of course, the mythical hammer wielded by Thor, and only Thor. It’s a question of being worthy; a question solved perfectly by this electromagnetic Mjolnir build.

Using an electromagnet is smart, right? Just plunk the thing down on something metal (that is itself super-heavy or well-anchored) and nobody will be able to pick it up. It starts to get more interesting when you add a fingerprint reader, allowing only Mjolnir’s Master to retrieve it from atop a manhole cover.

But for us the real genius in the build is that the hammer isn’t burning power from the four 12V batteries most of the time. All of the people in the video below could have picked up the hammer had they first nudged it off the metal plate with their foot. The build uses a capacitive touch-sensor to enable and disable the microwave over transformer used as the electromagnet. An engineering trick like this really separates the gods from the posers.

We hate to admit it, but this is probably a cooler build than the Telsa-Coil powered Mjolin that [Caleb] built a few years back. Still, his held up as the best for many years, and if you’re going to be displaced this really is a build worthy of the new title: coolest Mjolnir hack.

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Electronic Ruler Works Out Logic Truth Tables

October 13, 2015 by Mike Szczys 23 Comments

Like [Brad], we’ve seen a number of PCB rulers out there. [Brad] was looking to take the idea and run with it. His DigiRule is a ruler with a logic gate simulator. What he built is a mash-up between PCB rulers, and the concept of electronic business cards.

All told it simulates seven logic gates, four flip-flops, and includes a four-bit counter. On one end of the ruler a CR1220 battery feeds the 18F43K20 which is performing the logic operations using buttons and LEDs. Of course the truth tables are printed on the back silk-screen, but playing with the lights is a lot more fun. We do find it fairly amusing that the centimeters on the bottom of the ruler are notated in binary.

It makes a lot more sense to hand out rulers than business cards; people might actually use them after you leave and you can still include contact info. This form-factor also breaks the mold. You can have a lot more space on a ruler and you’re not constrained by thickness (although [Limpkin] solved that problem). While we’re on the topic of business cards [ch00f’s] USB etch-a-sketch style card and this logic-based information delivery device top our favorites list.

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Homemade Soldering Station Does It Better

October 11, 2015 by James Hobson 34 Comments

Soldering stations are probably one of the most important tools in the hacker’s arsenal. Problem is — good ones are expensive, and sometimes the only difference between being okay at soldering versus being great at it, is the quality of the tool you’re using! Which is why [Albert] and [Matthias] decided to make their very own home-made Weller clone.

Since the most important part of the soldering iron is a good tip, they’re using a needle from Weller — they just need to be able to control it. They designed a 3D printed housing (source files here) for a small 1.8″ LCD screen, an Arduino Pro Mini and a MOSFET shield, and the 12v 8A power supply they chose. There are only two controls — on/off, and a potentiometer for adjusting the temperature.

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The Worst CAD Package Ever Is Still Handy

October 5, 2015 by Al Williams 21 Comments

A lot of great schematics wind up on the back of bar napkins or diner place mats. When inspiration strikes, you have to capture it, after all. Today, you are as likely to draw schematics on a computer and there are plenty of options for that; if you can install software your options are almost limitless. And if you have a modern Web browser, there are lots of good options that don’t even require an install.

But what about those times when you need a quick schematic to pop into a presentation? You are on some ancient conference room computer where you can’t install anything and it’s still running a browser that understands the <BLINK> tag? Try out the Klunky Schematic Editor. Your browser will need Javascript, but that’s about all. No HTML 5 or anything fancy.

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The Perfect Pen Knife Handle

September 24, 2015 by James Hobson 44 Comments

If you’ve ever tried to use a pen knife for anything other than cutting open a box or slicing material in one direction, you’ll know they really aren’t that ergonomic. When [Seamusriley] started Architecture school a few years ago he started on a journey — an epic journey to make the perfect pen knife handle.

He started by analyzing existing handles — the biggest problem with them is the skinny pen shape causes hyper-extension of the first joint in your index finger, so once he identified that as the root cause he started crafting a more ergonomic version. He started out with foam, then up to wood carved by hand, then 3D printing, and back to wood — but this time, with a CNC machine. Literally dozens of prototypes later, he’s come up with a very nice pen knife handle, so much so, he was asked to present it around Boston at design events!

This is a great example of the hacker mindset — identifying a problem, trying out a solution, trying out another solution, trying out a solution… and then finally getting to a finished product. It’s the tenacity that keeps us going which rewards us in the long run.

[via r/somethingimade]

A Better Spectrum Analyzer For Your Rigol Scope

September 22, 2015 by Eric Evenchick 11 Comments

The Rigol DS1000 series of oscilloscopes are popular with hobbyists for good reason: they provide decent specs at a low price. However, their spectrum analysis abilities are lacking. While these scopes do have a Fast Fourier Transform (FFT) function, it’s limited and nearly useless for RF.

[Rich] wanted a spectrum analyzer for amateur radio purposes, but didn’t want to build his own sampling hardware for it. Instead, he wrote PyDSA, a software spectrum analyzer for Rigol DS1000 oscilloscopes. This tool uses the USB connection on the scope to fetch samples, and does the number crunching on a far more powerful PC. It’s able to plot a 16,000 point FFT at two sweeps per second when run on a decent computer.

PyDSA is a Python script that makes use of the Virtual Instrument Software Architecture (VISA) interface to control the scope and fetch the sample data. Fortunately there’s some Python libraries that take care of the protocol.

[Rich] is now able to use his scope to measure amateur radio signals, which makes a nice companion to his existing Teensy based SDR project. If you have a Rigol, you can grab the source on Github and try it out.