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Subject: Re: [Homebrew_PCBs] Re: Large or little bubbles

From: "Stefan Trethan" <stefan_trethan@...>
Date: 2005-12-23

> I think about a suction cup in center of the board conected in some
>
> way to an outside little motor.

You better have one very large pad in that place than, or a groundplane ;-)

>
>
>
> Adrian


The rotating thing might be a OK idea.
if anyone is going to experiment with movement of either air or pcb
consider using magnets like in a stirrer. Small neodymium magnets are
cheap and surely will follow each other through the glass easily. You can
have the motor outside, nice and dry, and the magnet inside the etchant
can be encapsulated easily.

By the way i agree the hose must go out through the top to avoid any
etchant coming into the pump.

Actually, when i suggested the moving air nozzle was thinking not of a
pendulum, but of a rotating tube, like a barber's pole you know, with
holes in a spiral pattern. At any time only one or few holes are on top,
spewing air, but there is a total of very many holes in different places.
Just an idea....
Might be easier to make the pole a bit shorter than the tank, and not
rotate it but instead slide it back and forth with a magnet one the
outside.


ST