If you’re in to making your own PCBs at home, you know the trials of etching copper clad boards. It’s slow, even if you’re gently rocking your etch tank or even using an aquarium pump to agitate your etching solution. [cunning_fellow] over on Instructables has the solution to your etching problems, and can even produce printmaking plates, jewelry, photochemically machine small parts, and make small brass logos of your second favorite website.
The Etchinator is a spray etcher, so instead of submerging a copper clad board into a vat of ferric or cupric chloride, etching solution is sprayed onto the board. We’ve seen this technique before, but previous builds use pumps to spray the etching solution and cost a bundle. [cunning_fellow]’s Etchinator doesn’t used pumps; it’s driven by two cordless drill motors sucking up etching solution through a hollow tube.
The basic idea behind the build is sticking a vertical PVC pipe in a box with etching solution. Mount an impeller in the bottom of the tube, drill many small holes in the side of the tube, and spin it with a motor up top. The solution is sucked up the tube, sprayed out the sides, and falls back down into the reservoir. Put a masked off copper board in the tank and Bob’s your uncle.
Not only did [cunning_fellow] come up with an awesome PCB etching solution, but the same machine can be used for etching brass plate for printmaking, and even photoetching brass sheets for model planes, trains, and automobiles. The quality is really amazing; the Instructables robot above was etched out of 0.7 mm thick brass, with an etch depth of 0.35 mm with only 0.05 mm of undercut. A very awesome build that is already on our ‘to build’ project list.