Friday, May 29, 2009


I've been etching numerous PCBs at work for various little projects, and one of the annoying parts of etching is the actual etch process. The copper clad board is immersed in Ferrocloric acid in order to etch away the exposed portions of the board. During the etch, the liquid should be agitated in order to achieve maximum saturation. I got tired of jiggling the tupperware around for 20 minutes, so I built an agitator!

You can see that this project uses the make controller as well as an erector set. I used a HiTec 645MG servo for the agitation.

Here's the video. Rated PG-13 for intense battle sequences and some scary images:


I didn't have anything to etch at the moment, so the video shows the tub with Mountain Dew in it instead. Maybe that would be good for etching designs in teeth...

As you can see, the servo oscillates above and below the horizontal. This ensures that the acid flows both ways.

I made a circuit board for a device we're calling FreePoint. This is the prototype design that's made to plug in as an arduino shield. The final version will be standalone.