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Homebrew PCBs

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Message

Re: Etch safe materials, etc etc

2004-12-15 by dioxide

Norm Wrote;
>Just got to thinking - In lab work years ago, a standard stirring 
>mechanism was a motor (variable speed) driven magnet base for a liquid 
>container (read: etchant tank) with a Teflon encapsulated magnet just 
>dropped into the tank. The base magnet would spin the teflon 
>encapsulated magnet inside, stirring the liquid. Higher speeds could 
>generate a full whirlpool in a 8-10" deep flask. I'd bet that the 
>magnet s are still a common lab item - and should be cheap. The only 
>etchant contact would be teflon. Might be an etchant agitator for PCB work.


This is exactly what I had in mind, except it's a simple matter to
seal an iron slug or magnet inside of acrylic, so I wont have to worry
about teflon compatibilities with etch chemicles.
I also wont be spinning it near fast enough to create a vortex, just
enough to get things moving a bit.


Stan Wrote;
>well, it would be hard to use a prop. what could work is if you use the 
>propshaft vertical
>out of the tank, and a motor on top of it.
>Doesn't work for me because the tank is only 2cm wide, no space for a prop.
>it would generate a circular current in the tank.

There will be no shaft, the prop itself will be spun by magnetic
force, from a magnet outside of the tank.
Since I want to make the tank myself, I can design the whole thing
around the idea of moving the liquid with the prop, should be no
problem.
I should be able to aim the prop in whichever direction I want, to
make the water move in the direction I want.  I was thinking of making
it move in a vertical circle instead of horizontal.

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