Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

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