Printable Wax As PCB Etch Resist

January 31, 2011 by Mike Szczys 28 Comments

What if there were only two steps for making your own printed circuit board; print, etch? That’s what [Jeff Gough] has been working on and he presented the process in his talk at 27C3. In the first portion of the video after the break [Jeff] talks about various industrial PCB manufacturing processes in a depth you may not have heard before. We found it to be interesting but at about thirty minutes into the clip he begins the presentation of his modified printer. It’s an inkjet that can print wax onto copper clad board. The wax acts as a resist for chemical etchants, and provides very high resolution. He’s using a heavily modified print head, which brings to mind that diy piezo inkjet head which also has wax printing in its future plans. This certainly seems promising and if the process can be simplified it might do away with the toner transfer method.

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Make Presents: The Multimeter

January 26, 2011 by Caleb Kraft 17 Comments

This video falls under the category of things we want to send people when they ask “how do I get started with electronics”, and we get asked that a lot. For those of you who have been working with electronics ~~for years~~ at all, you can skip this entire video. That is, unless you really want to watch an instructional video on multimeters. In the video, which we’ve included after the break, they talk about the differences between different meters, the common uses and how to actually use the meter to get the results you need. Stuffed full of useful information, this video will get those of you who are still reading up to snuff pretty quickly. Now go use your multimeter to do some hacking!

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Magnetic Digital Scale

January 21, 2011 by Mike Szczys 20 Comments

Above you see a solenoid being used as a digital scale. The magnetic field from the coil in the base levitates the platform above, where a load to be measured is place. This floating platform has a permanent magnet in it, hovering above a hall effect sensor in the base. As the distance between that magnet and the sensor changes, the measurable magnetic field changes as well. The hall effect sensor is linear so the measured value can easily be correlated with a weight. In the video after the break [Vsergeev] demonstrates the device using test weights to show off its 0.5 gram resolution. He thinks that with a few hardware improvements he could easily achieve 0.1g accuracy.

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Make Your Own Odometer From Scraps

January 19, 2011 by Greg R. Jacobs 11 Comments

For those out there who would enjoy a quick and interesting weekend project, this odometer made by [PeckLauros] is for you. Featured on Instructables it is made from the simplest of materials including some cardboard, a calculator, wires, glue, hot glue, magnetic drive key, an old CD and a reader, and a rubber band. The magnets, when attached to the CD work in a calculation to add 0.11m to the calculator when a magnet closes the circuit. [PeckLauros] points out that since it is a homebrewed device, it does have flaws such as adding 0.11m twice when the CD is rotated too slowly. It is easily fixed by simply running faster. The video is below the break.

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$20 Fuel Injector Tester

January 16, 2011 by Mike Szczys 39 Comments

[Dino] is an auto mechanic and needed a way to test out fuel injectors. Commercially available tools start well over $100 and go up from there, but he built his own for about $20.

The injectors have a coil in them that needs to be tested. His design calls for a series of 0.008 millisecond pulses to test the coil. He started by setting up a 555 timer to output a one second pulse. This signal is fed into a second 555 chip that outputs the 0.008 pulses and in turn actuates a MOSFET to switch the coil on and off. To use it [Dino] connects to a 12V bench supply and to the injector, using a single button to start the test. See him explain the setup in the video after the break.

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Pin Header Sizing Machine

January 13, 2011 by Mike Szczys 41 Comments

[Ammon Allgaier] built a tool that can break apart pin headers with a high level of precision. In the video after the break he demonstrates the built-in features. They include an adjustable stop to select the number of pins you’d like in each chopped segment. There’s also a small groove in the input side which the plastic frame of the header rides in. Just insert until it is touching the stop, and push down to break the header at the correct location. A couple of springs return the cutting tooth to its resting position, allowing you to make quick work of chipping up a 40-pin blank. This machine will become a nice companion for that automatic wire cutter.

This is great for single headers but we’ve long been on the lookout for a reliable way to snap off double pin headers. Far too often we make mistakes when trying to use two pair of pliers. If you know of a better way, please share your method in the comments.

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Hold, Fast, And Max Features On A Digital Caliper

January 12, 2011 by Mike Szczys 67 Comments

While adding an RJ-11 connector to his digital calipers [BadWolf] slipped, shorting out a pin and accidentally discovered new features. He intended to add a port for reading measurement data electronically, but after the slip-up an ‘H’ appeared on the LCD screen and the measurement was frozen at the same number. At first it seemed like he may have killed the device, but this is actually a hold function. A little bit more playing around and he discovered that a combination of button presses can also enable a fast function which speeds up the rate at which the display changes its reading. There is even a max function that only updates the display if the reading is higher than any previously displayed measurement. These are nice features which he uses by connecting a momentary push switch between two of the output pins, details we gleaned from the annotated video after the break. He doesn’t say which pins work for him, but we’d bet one of them is the ground pin on the port, and the other is one of the two data pins. Do some investigating with your own calipers and let us know what you find in the comments.

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