Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "cruizzer77" <atlantis7@g...> 
wrote:
> Well this is interesting. The original patent paper clearly states 
> that the etchant is pumped up the tube using a sprial mounted 
inside 
> the tube. This sounds reasonable to me but unfortunately will be 
> close to impossible to fabricate such a spiral. Somebody who has at 
> least a middle-sized lathe could probably try to turn it out of a 
> plastic bar, similar to turning a thread. I think I'll try the 3-
> hole type next.
> 
> Regards
> Martin
> 
> 
> Actually, sepending on the speed of the twists, or twists per inch, 
one can take PVC and just twist it into shape like a wrought iron 
railling spindle.  Or, one could hand file a part without too much 
difficulty.

Dave