Homebrew pcb etchant agitator?

[pryde]

Hey folks I am curious of what type of contraptions you have come up with for pcb etching. I don't etch pcbs but do face plates for my builds and am really tired of sitting for 20 minutes and manually agitating the etchant solution in a bin.

I have a 9vDC motor I am pondering it's use for a SIMPLE device to agitate or gently rock a small etchant bin back and forth. I am visualizing an offset rod attached to the motor spindle that will turn "oblonged" and rock a bin sitting on top of it up/down as it spins below.

The motor is high speed though and RPMs are way to fast for this application. I put a 10k series pot in to sag voltage and slow the motor down but the pot is smoking so a new plan is in order 

Maybe I can try a 10w series resistor in the voltage line to better dissipate the heat. I want this as simple as possible so please share your solutions, thoughts, ideas, etc. I would love to see and hear them.

Thanks everyone.

[gtr2]

I've seen some people aerate with an aquarium pump.

Josh

[m-Kresol]

You could build a magnetic stirrer like this one:

http://www.instructables.com/id/Magnetic-Stirrer/

basically just a magnet glued to an old PC fan and a stick magnet for the solution. Downside being that the stick magnet might be in the way of your pcb/whatever your etching

[billstein]

I use a foam brush and keep brushing the top of the pcb while it it etching. I've found that if the etchant is warm that this technique is pretty quick.
I did the rocking the bowl of etchant for a long time and also started looking at agitators. Since I've been using the foam brush I stopped looking.

[selfdestroyer]

Here is my ghetto one from parts at Lowes. Its still working strong. I have since added a small heating pad to it that I cut to size. I got it from a pet store for reptile tanks. Works well.

Cody

[pryde]

Here is my ghetto one from parts at Lowes. Its still working strong. I have since added a small heating pad to it that I cut to size. I got it from a pet store for reptile tanks. Works well.

Cody

Ha that is awesome! Ghetto is good 

couldn't really make out the contraption, gearing, etc under there. what the heck is it?

[selfdestroyer]

Its actually a ice maker motor from a refrigerator. Since its a very slow RPM motor and its what my father-in-lay had on hand. I am not taking full credit for this thing since my father-and-law and I with a bottle of scotch later came up with it. I am looking at making a new one with an Arduino that will also control the heat but thats pretty far down on the "list to do".

There is also this one that I wanted to try out for some time.
http://www.instructables.com/id/PCB-agitator-from-an-old-CR-ROM/

Cody