Classical VCR head jog wheel

[Osgeld] takes on the classic VCR head jog wheel in this instructable. He has done a fantastic job not only in his build quality, but in the quality of the writeup. As he points out, the idea of using the head as a jog wheel isn’t new. His construction and build quality however have yielded a fantastic looking reliable device that we would be proud to have sitting on our desk.
As usual, the most interesting bits of the writeup are how he solved problems he encountered. For example, he’s using an optical mouse to detect the motion of the wheel. This requires that he print out a pattern to mount opposite the optical sensor. This sounds straight forward enough, but he found the results to be less than stellar. He documented his fix, basically reworking it in GIMP, so others can save some time. That is how tutorials should be. Great job [Osgeld].

Touch sensors: overview, theory, and construction

This collection of touch sensor information should be of interest to anyone who liked the simple touch sensor post from Thursday. That was a resistive touch sensor and is covered in detail along with AC hum sensors that trigger based on induced current from power lines around you, and capacitive touch switches like we’ve seen in past hacks. Each different concept is discussed and clearly illustrated like the slide above. [Giorgos Lazaridis] has also put together individual posts that build and demonstrate the circuits. We’ve embedded his resistive sensor demo video after the break and linked to all three example circuits.
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Printable wax as PCB etch resist

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.

Etch-a-Sketch computer is a surprisingly simple hack

We’re not sure whether to call this an Etch-a-Sketch upgrade or a computer interface downgrade but either way it’s unique. [Martin Raynsford] added a familiar red frame to his computer monitor with classic white knobs that control horizontal and vertical cursor movement. There’s even the click option by pressing the buttons in and, as you can see after the break, the modifications result in a perfectly usable digital Etch-a-Sketch. We’ve seen a lot of computer controlled versions of the toy which use fancy parts and take quite a bit of skill to build. This mimicry of the functionality is easy to build and the idea is genius in its simplicity. [Martin] separated the encoder wheels from a mouse. He placed each on one of the knobs and ran wires for sensors and micro-switches back to the original PCB which is stuck to the back of the monitor. From the computer’s point of view it looks and acts like a normal mouse but this is so much more fun (and less productive). Read the rest of this entry »