Alright, so I had some post-publication weirdness following my last post, and it took me a few days to figure out exactly what was up, but I think I finally have all the details, and I learned a lot in the process.
So, a few weeks ago, I made a gadget that I called the “Ice Breaker”. It was a simple persistence of vision toy that would spell out the word “Hello” on your hand as you wave to someone. The original didn’t work too well, so I made a new version that works great! Here’s a video:
Stick around until the end to see what was going on with the old version.
So I had a chance to test my bullet counter this weekend!
I met up with two redditors this past Sunday and they let me borrow their guns for testing. I wish I could tell you that all went well, but I had some pretty interesting problems… Continue reading
When you feel like doing some really rapid prototyping and don’t want to wait around for a board to come in the mail, you usually have to print a board of your own. I’ve done this a number of times (the original bullet counter was a home-printed board).
The whole process has a number of steps (which I will be going into in another post), but one of them involves printing an acid-resistant substance on a copper sheet and dissolving the un-coated copper in an acid. As I have mentioned earlier, I had some really crummy ferric chloride acid that didn’t do a very good job of etching my boards. I would usually end up sitting around for an hour or so waiting for it to etch only to have the etchant start to eat under my etch-resist while other free portions were still un-dissolved.
Ferric chloride is also kind of pricey, so I decided to try my hand at some home-brew etchant. I found a recipe online that calls for just two ingredients:
Muriatic Acid (HCL) and Hydrogen Peroxide (H2O2)
