Replacing Knurled Thumb Screws

August 6, 2013 by 32 Comments

Screw

[Pete] bought himself an old South Bend lathe, but unfortunately some of the thumb screws were missing from this fine old machine. Originally, the lathe had knurled thumbscrews, and with a thumbscrew from Ace hardware the lathe itself was functional, but by no means looking its best. With a lathe you can make just about anything, so [Pete] decided he would make his own knurled thumbscrews and bring this lathe back to life.

Knurling is a diamond or linear pattern of indentations usually found on fancy metal knobs, flashlights, and other equipment that needs a good grip. While there are knurling tools for lathes, [Pete] decided to use his knurlmaster – a handheld device that looks like a pipe cutter – to cut a few knurls into a steel bar.

As for making this knurled bar into a proper thumbscrew, [Pete] shows us two methods: the first is tapping the knurled steel, putting in the right screw for the job, and securing the parts with Loctite. The second method involves cutting the threads on the lathe, an excellent example of how a lathe can make just about anything, even parts for itself.

Bench Equipment Tip: Screenshot Of Old Oscilloscopes

August 6, 2013 by 18 Comments

oscillocam-oscilloscope-camera-accessory

Here’s a quick tip on capturing the output of oscilloscopes that don’t have that native feature. [Paulo Renato] used a cookie tin as a camera cowl for capturing CRT oscilloscope screenshots.

We figure if you’ve got any kind of functioning oscilloscope you’re lucky. And although it’s nice to pull down the measurements to your PC on the newer models, the results [Paul] gets with this rig are still satisfactory. The plastic cookie box he used blocks out ambient light while holding the camera at a consistent focal length. He used some flat black spray paint to make sure the obnoxious yellow plastic didn’t interfere with the image, then drilled a hole which fits tightly around his camera lens.

You’ll need to monkey with the exposure settings to get the best image. But once you’ve got it dialed in it should be the same every time you want to take a picture of the screen.

Making Digi-Key Much, Much Prettier

August 6, 2013 by 41 Comments

digi

We all love Digikey, but of all the major component retailers out there, their web interface really isn’t that great. A lot of online sources for parts are much, much prettier, but nothing a good Greasemonkey script can’t fix. This is all the work of [Ben], and adds a ton of really, really useful features to the Digikey web interface.

First up is a whole bunch of pictures right at the top of the search results. If you’re looking for pin headers or weird connectors, this is an astonishing useful feature that will help you select the right part faster. After that is a ‘helper’ button for voltages. As you know, selecting a part with a 5V input requires clicking multiple options including 3.3-5V, 2.3-6V, and 5-40V. Clicking on the helper button and entering 5 V will select all the entries in the filter that contain a 5V part.

[Ben]’s project has been tested with Firefox and Chrome with Greasemonkey extensions. Head on over to his project page for a much better demo of all the features for this really great tool.

Turning A Rubidium Standard Into A Proper Tool

August 5, 2013 by 42 Comments

Rb

You can find rubidium frequency standards all over eBay and various surplus dealers. They’re actually quite interesting devices, able to generate a 10 MHz sine wave with enough precision to be a serviceable atomic clock. While these standards can find themselves very useful in a lab, they’re only a component, and not a working-out-of-the-box device. [Gerry] decided he would fix that, turning his rubidium standard into a proper piece of bench equipment, all in a single afternoon.

[Gerry]’s first step was finding a proper enclosure for his new piece of equipment. Most of the time, choosing an enclosure is practice in the art of compromise. This time, though, [Gerry] found the perfect enclosure: an old piece of video distribution equipment. On the back of this box, there are a ton of BNC plugs, perfect for attaching to random lab equipment and feeding them a signal from the rubidium standard.

After going through the video circuit and changing the 75 Ohm outputs to 50 Ohms, [Gerry] wired up an eBay power supply, fan, and a small circuit with an 8-pin PIC to complete his new tool. The rubidium standard does get freakishly hot, but hopefully mounting it to a large aluminum box with a bit of cooling will keep all the added electronics in working order.

[Gerry] did all this in just under 5 hours. An impressive feat, given that he probably spent that much time editing the video, available below.

Continue reading “Turning A Rubidium Standard Into A Proper Tool” →

Raspberry Pi Camera Built As Part Of Advertising Campaign

August 5, 2013 by 22 Comments

the-rpi-camera

Here’s yet another example of well targeted advertising. This camera built around a Raspberry Pi is a giveaway from Sprite. The “lucky” winner of the camera will have the pleasure of seeing the Sprite logo as a watermark on all of the images they snap with it. But in the right hands it’s a simple hack to remove that “feature” (they published the Python script that adds the watermark) or to just scrap the parts for another project. Either way, Sprite got us to say their name three times in this paragraph so the campaign worked.

The most obvious part of this build is the custom cast resin case that they came up with which is a gaudy cartoon-like monstrosity. It protects the case-less Raspberry Pi board, and mounts the Pi Camera board so that the lens is positioned correctly. The lipstick-sized module mounted in the lower back half of the case is a 2400 mAh portable power supply with a USB charging port sticking out the side. This makes us wonder, do you have to wait for the RPi to power up before snapping a picture? If the size and color didn’t get you noticed by everyone the shutter sound will. it shouts the name of the soda company whenever you press the shutter release button.

If you’re more of a high-end photography enthusiast this DSLR wedded with an RPi will be of more interest.

Have You Failed Hard Enough To Be On Hackaday?

August 5, 2013 by 46 Comments

hackaday-fail-announcement

There’s so much more to be discovered when your projects just don’t want to work. Grinding out the bugs, getting past roadblocks, and discovering gotchas is where real hacking know-how comes from. But most people aren’t motivated to document their failures. We want to change that.

We want to roll out a new weekly feature that showcases failure… well documented failure. But we need YOU to give up the goods. Write about your failed experience on your blog, post it to our project forums with [FAIL] in the title, or you can just write everything in an email and send it to us. Which ever way you choose, you’ll need to tip us off that you’d like to make it to the front page (come on, it’s not bragging since it didn’t even work!). If you already know of well documented project fails send in those links too even if they’re not your projects.

Make sure you include at least one descriptive image — snapshots, diagrams, schematics, screencaps, anything that tells the story is fair game. To show you what we’re after here’s a few of our favorite failed projects:

We’d like to point out that all of these projects are interesting ideas that show off missteps along the way. We will not be trashing on your skills as a hacker, but instead celebrating the lessons learned and hearlding the sharing of ideas from otherwise doomed projects.

Centimeter-level Precision GPS For $900

August 5, 2013 by 60 Comments

[Colin] and [Fergus] have been working with GPS for years now, and like most builders of really cool things, they’re often limited by the precision of off-the-shelf GPS units. While a GPS receiver is usually good for meters of accuracy,  this just isn’t good enough for a lot of projects. What you need is centimeter-level accuracy, something the guys have managed to do with their Piksi GPS receiver.

Where most GPS receivers only look at the data coming from the GPS satellites orbiting overhead, the Piksi uses another technique, real-time kinematics (RTK), to determine the receiver’s location with exacting precision. The basic idea behind RTK is to look at the carrier frequency of the GPS signals at 1575.42 MHz. This frequency has a wavelength of 19 cm, compared to the alternating 1s and 0s of the that are transmitted at around 1 MHz, or about 300 meters between each bit. While centimeter-level precision isn’t possible with only one receiver, two of these Piksi boards – one base station and one on a vehicle, connected via radio link – can make for a very exacting high-accuracy GPS receiver.

Previously, commercial RTK GPS systems have cost thousands of dollars – making a quadcopter or other homebrew project that relies on this level of precision nonsensical. [Colin] and [Fergus] have built hardware that can bring the price of this setup to under $1000. As a bonus, the Piksi board can also receive from other constellations such as Galileo and GLONASS. A very impressive piece of hardware, and we can’t wait to see the applications.