Homebrew PCBs

On Wed, 23 Mar 2005 22:03:06 -0800, RMustakos <rmustakos@...>  
wrote:

> Stefan
> I remember you talking about having an issue with the etchant forming a
> vortex around the bottom of the pipes.
> Originally I was thinking you should put a plate on the bottom of the
> pipe that was bigger than the vortex.  Took me a second or two to figure
> out that would just make things worse.
> Than the thought occurred to do the the opposite - constrain the fluid,
> and here are a couple of ways:
> Use a plate that does not move, and that keeps the fluid from developing
> a vortex outside of the pipe.
> Place crumpled plastic mesh at the base, that would induce a bunch of
> drag and slow any vortex.
> Place plastic vanes that are lined up radially from the bearing out.
> If they go higher than the fluid, they would preclude a vortex from
> forming except in the space between them and the spinning tube, which
> can be minimized.
> Richard


I think the vanes are the best idea. a spoon can stop a vortex in a coffe  
cup real fast...
will do..

ST