This isn’t meant to be the definitive PCB etching post. I don’t have any experience etching boards and was hoping readers could contribute their best/favorite methods for etching boards in the comments.

We’re linking to Tom Gootee’s page on toner transfer etching. The first step is to print the design on glossy paper using a laser printer. An iron is then used to transfer the toner to a prepped copper board. The board is then soaked in etchant to remove the exposed copper. The printer toner is mostly plastic and resists the etchant. Once the board  is etched, Acetone is used to remove the toner. Tom has been keeping his site up to date and as his research progresses.

Continue reading “Printed Circuit Board Etching” →

Probably the most popular project this summer was the MIT Disco Dance Floor. The build team eventually released the controller schematics and software. Several other projects spun off as a result of this.

We’ll start with the Disco Bar (since it has the most pictures). David has been actively building the bar and is nearing the finish line. He built a bar instead of a floor because as a white guy from  Wisconsin, he’s a far better drinker than dancer. I tend to feel one leads to the other.

David’s project is driven by software that Washington University students developed while building their Vertigo Dance Floor. The software includes a cool utility for building animations.

Also: Monkey see, monkey build and Tom’s Blog (in German)

[Update: We forgot to include the DECT phone system controllable Disco Dance Floor by Blinkenlights at 2005’s best hacker camping extravaganza, What the Hack. Another pic by an attendee of wth is here.]

Continue reading “Disco Dance Floor Roundup” →

This hack was put together by reader [Forrest Cook]. He was wondering if there were any radioactive materials in his rock collection. This is an add-on box for a 60s era Victoreen CDV700 Geiger counter. Vintage gieger counters don’t actually count; they use an analog meter with an integrator circuit to do short term averages. Forrest’s box plugs into the headphone jack of the Geiger counter and does true digital counting with a Motorola microprocessor. The signal could also be sent to a computer with a little modification. He did find a handful of radioactive rocks, but nothing that was serious enough to worry about.

Continue reading “Count Accumulator For Radiation Levels” →

Reader [Josh McCormick] hacked this awesomely drunk animatronic Santa. Here’s a cached video link. He purchased the 5 foot tall singing and dancing Santa Claus at Walmart for $50 with the intention of modifying it for an art show. Once he got it home he began tearing it down. He found the brains of the device in the left foot (just like Santa!). The motion control is all analog and there is a hidden potentiometer that controls the dancing rate (jigginess). Josh used a BS2P40 Parallax BASIC Stamp for the digital control of the device and the sound samples were stored on a Quadravox QV306M4. To get the movements in sync, Josh recorded the performance as the sound clip was being played back. The movements were stored on a 24LC515 EEPROM. With some last minute work he got it to the show on time, but it unfortunately broke during exhibition and he did not win. There should be some consolation in the fact that it is on the internet now and will be seen by thousands of people instead of a handful.

Continue reading “Drunk Animatronic Santa” →

While some railgun projects are attempting to be the biggest and baddest, this one just wants to be functional. It’s not efficient or powerful, but it is really easy to put together. The barrel is constructed from two 3″ long pieces of aluminum weld bar with heavy duty Lucite sandwiched in between. The gap is only 1/16″. A disposable camera charging circuit plus 4 capacitors salvaged from other cameras provide the power supply. The projectile is a tiny piece of aluminum foil. It may not be the greatest gun ever made, but it looks like it would definitely be a good demo unit. Here is a coral cache of the site.

[thanks luke]

Continue reading “Micro Railgun” →

Pinhole cameras use a tiny pinhole as their aperture instead of a lens. Fran?s Besson designed this camera to take a 240 degree panoramic picture. The camera aperture slot rotates on one axis while the film rotates on a separate axis. The 8×20″ film is attached to a large drum mounted to the second spindle. The exposure length can be 18, 6, or 3 minutes depending on the voltage supplied to the drive motor.

Continue reading “Rotary Pinhole Camera” →

[Thomas] just wanted a simple, free drum machine to play with. He decided to build one himself using MS Excel. To get it up and running you need to download a .zip file that contains the .xls and .dll files. Grab some drum samples and you are ready to go. Each drum is mapped to a key and can be used with a game pad. Don’t worry he’s got some simple, Meg White, patterns to get you started. Not impressed? Well, tear it down and build your own machine.

Continue reading “Excel Based Drum Machine” →