Today I stopped by the makerspace to etch the circuit board for my second robot. The robot is a very simple line follower that uses a LM393 dual comparator IC. The complete design and build instructions can be found in the book Robot Building for Beginners by David Cook.
In addition to the usual hackery and makers working on their electric cars, Bret fired up the forge again last night. Rich turned some horseshoes into hangers, Adam flattened a steel rod, and Royce folded a metal bar.
In preparation for BarCampMilwaukee6 (this weekend!) Royce and I have been mass producing circuit boards for a “learn to solder” class we’ll be holding. The boards are 1.5″x1.5″ square and include a battery, two resistors, traces in the shape of our logo, and two red LEDs for eyes. The copper traces were tinned using “Tin It” to prevent oxidation and make it easier to solder. We’ve made 65 of the “tie pins” so far and the project gave us an opportunity to tweak our methods for PCB etching. We prefer etching with ferric chloride, but muriatic acid and hydrogen peroxide are looking more attractive as they’re cheaper chemicals, can be obtained locally, and etch much faster without heating. Also, red Sharpie markers seem to work really well at cleaning up traces with the muriatic acid solution. Specifically red, not sure why.