Misc Hacks

4190 Articles

Build This Barn Door Tracker Today, Take Stunning Shots Of The Galaxy Tonight

December 15, 2016 by 18 Comments

Think you need some fancy equipment to get stunning shots of the night sky? Surely those long-exposure shots that show the Milky Way in all its glory take expensive telescopes with complicated motor-driven equatorial mounts, right? Guess again – you can slap together this simple barn door tracker for a DSLR for a couple of bucks and by wowing people with your astrophotography prowess tonight.

Those stunning, deeply saturated shots of our galaxy require a way to cancel out the Earth’s movement, lest star trails ruin your long exposure shots. Enter the barn door tracker, a simple device to let you counter the Earth’s rotation. [benrules2]’s version of the tool is ridiculously simple – two boards connected by a hinge. A short length of threaded rod with a large handle passes through a captive nut in the upper board.

A little trig allows you to calculate how much and how often to turn the handle (by hand!) to counter the planet’s 0.25°/minute diurnal rotation. Surprisingly, the long exposure times seem to even out any jostling introduced by handling the rig, but we’d still imagine a light touch and a sturdy tripod would be best. Those of you with less patience might automate this procedure.

It seems a lot to ask of a rig that you could probably throw together in an hour from scrap, but you can’t argue with [benrules2]’s results. His isn’t the only barn door tracker we’ve covered, but it looks like the simplest by far and would be a great project to build with kids.

[via r/DIY]

Measuring Spurious Emissions Of Cheap Handheld Transceivers

December 14, 2016 by 43 Comments

If you buy an amateur transceiver cheap enough to make a reasonable grab bag gift or stocking stuffer, you get what you pay for. And if this extensive analysis of cheap radios is any indication, you get a little more than you pay for in the spurious emissions department.

Amateur radio in the United States is regulated by the FCC’s Part 97 rules with special attention given to transmitter technical specifications in Subpart D. Spurious emissions need to be well below the mean power of the fundamental frequency of the transmitter, and [Megas3300] suspected that the readily available Baofeng UV-5RA dual-band transceiver was a little off spec. He put the $20 radio through a battery of tests using equipment that easily cost two orders of magnitude more than the test subject. Power output was verified with a wattmeter, proper attenuators were selected, and the output signal scanned with a spectrum analyzer. Careful measurements showed that some or all of the Baofeng’s harmonics were well above the FCC limits. [Megas3300] tested a few other radios that turned out to be mostly compliant, but however it all turned out, the test procedure is well documented and informative, and well worth a look.

The intended market for these radios is more the unlicensed crowd than the compliant ham, so it’s not surprising that they’d be out of spec. A ham might want to bring these rigs back into compliance with a low pass filter, for which purpose the RF Biscuit might prove useful.

[via r/AmateurRadio]

TP-Link Debug Protocol Gives Up Keys To Kingdom

December 14, 2016 by 25 Comments

If the headline makes today’s hack sound like it was easy, rest assured that it wasn’t. But if you’re interested in embedded device hacking, read on.

[Andres] wanted to install a custom OS firmware on a cheap home router, so he bought a router known to be reflashable only to find that the newer version of the firmware made that difficult. We’ve all been there. But instead of throwing the device in the closet, [Andres] beat it into submission, discovering a bug in the firmware, exploiting it, and writing it up for the manufacturer.  (And just as we’re going to press: posting the code for the downgrade exploit here.)

This is not a weekend hack — this took a professional many hours of serious labor. But it was made a lot easier because TP-Link left a debugging protocol active, listening on the LAN interface, and not requiring authentication. [Andres] found most of the information he needed in patents, and soon had debugging insight into the running device.

Continue reading “TP-Link Debug Protocol Gives Up Keys To Kingdom” →

The Many Uses Of The Neon Lamp

December 12, 2016 by 44 Comments

Neon lights are that kind of nostalgic item that everybody seems to love. The neon lamp is a type of gas discharge lamp, they generate light when an electrical discharge travels through an ionized gas, or plasma. When the voltage between the electrodes exceeds certain threshold, the gas ionizes and begins conducting electricity. The basic process that generates light is the return of the ions to the ground energy state, with the emission of a photon of light. The light color depends on the emission spectra of the atoms in the gas, and also  on the gas pressure, among other variables.  Gas discharge lamps can be classified by the pressure of the gas:

  • Low pressure: includes the neon lamp, fluorescent lamps and low pressure sodium lamps.
  • High pressure: such as the metal halide, high pressure sodium and mercury vapor lamps.

Another classification comes from the heating method of the cathode:

  • Hot cathode lamps: the electric arc between the electrodes is created via thermionic emission, where electrons are expelled from the electrodes because of the high temperature.
  • Cold cathode lamps: In these, the electric arc results from the high voltage applied between the electrons, that ionizes the gas and conduction can take place.

High intensity lamps are another type of gas discharge lamp where a high power arc is formed between tungsten electrodes. Power levels of several kilowatts can be easily produced this type of lamp. Of course we can’t forget to mention nixie tubes, which are a type of cold cathode neon lamp, popular for building retro clocks. Fortunately, they are now in production again.

Continue reading “The Many Uses Of The Neon Lamp” →

The 3D-Printed Mutoscope You’ve Always Wanted

December 10, 2016 by 10 Comments

[John] got his hands on a 3D printer, and did what any hacker with a new toy would, printed himself a Mutoscope. (A what?) A Mutoscope is an early flip-book based motion picture machine, and in this case it displays 24 frames from “A Clockwork Orange”. [John]’s 3D-printed machine is, not coincidentally we assume, printed in orange plastic.

The model for the frame is up on Thingiverse, but there’s not all that much to it, honestly. It’s a frame and a few wheels that hold some skewers in place. The rest of the work is making the flaps.

But getting to the end product wasn’t a straight walk. [John] describes all of the starts and stops in his blog, aptly named “Fail Try Again”. We like seeing the whole process rather than just the final, seventh, iteration of the device.

Where to take this project next? We want to see a design with a mounting bracket for a cheap stepper motor built in. We’ve always wanted our own custom signage, and there’s nothing cooler than the flap-flap-flap noise that flip book pages make when being switched. We must not be alone in thinking so, because we’ve seen two beautiful DIY builds in the last two years: this one done in multiples for advertising purposes and this one done just for the lulz. [John]’s project is a lot simpler, and thus a lot more accessible. We hope it inspires a few of you to make your own.

LEGO Strain Wave Gear Is Easy On The Eyes

December 9, 2016 by 12 Comments

We are continually amazed by the things people do with LEGO and Technics, especially those that require incredible engineering skill. There’s an entire community based around building Great Ball Contraptions, which are LEGO Rube Goldberg machines that move tiny basketballs and soccer balls from one place to another. Except for a few rules about the input and output, the GBC horizons are boundless.

Famed GBC creator [Akiyuki] recently built a GBC module that’s designed to show the movement of strain wave gear systems. These types of gear systems are used in industrial applications where precision is vital. Strain wave gears are capable of reducing gear ratios in a small footprint.

Continue reading “LEGO Strain Wave Gear Is Easy On The Eyes” →

For Your Binge-Watching Pleasure: The Clickspring Clock Is Finally Complete

December 6, 2016 by 26 Comments

It took as long to make as it takes to gestate a human, but the Clickspring open-frame mechanical clock is finally complete. And the results are spectacular.

If you have even a passing interest in machining, you owe it to yourself to watch the entire 23 episode playlist. The level of craftsmanship that [Chris] displays in every episode, both in terms of the clock build and the production values of his videos is truly something to behold. The clock started as CAD prints glued to brass plates as templates for the scroll saw work that roughed out the frames and gears. Bar stock was turned, parts were threaded and knurled, and gear teeth were cut. Every screw in the clock was custom made and heat-treated to a rich blue that contrasts beautifully with the mirror polish on the brass parts. Each episode has some little tidbit of precision machining that would make the episode worth watching even if you have no interest in clocks. For our money, the best moment comes in episode 10 when the bezel and chapter ring come together with a satisfying click.

We feature a lot of timekeeping projects here, but none can compare to the Clickspring clock. If you’re still not convinced, take a look at some of our earlier coverage, like when we first noticed [Chris]’ channel, or when he fabricated and blued the clock’s hands. We can’t wait for the next Clickspring project, and we know what we’re watching tonight.

Continue reading “For Your Binge-Watching Pleasure: The Clickspring Clock Is Finally Complete” →