Homebrew PCBs

Yes that's it! The 3-hole version works basically. I actually did 
angle the holes a bit and at 7'000 rpm the water splashed out of the 
holes up to about 5 cm from the bottom. The drill I used to drive 
cannot spin faster, so it seems as if I needed a high speed motor. 
Once this is done I will probably also try a base plate with only 
one hole in the middle. Does someone have an idea from what kind 
of "everyday device" a motor with a speed range up to 10'000 to 
12'000 rpm could be salvaged? I think not even a vacuum cleaner 
spins that fast, apart from the fact that those motors are 
considerably large. Another problem will be that my bearings in the 
condition being will not withstand those high rpms.

Regards
Martin






--- 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
> 
> 
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Adam Seychell 
> <a_seychell@y...> wrote:
> > Phil wrote:
> > > --- In Homebrew_PCBs@yahoogroups.com, Markus Zingg 
> <m.zingg@n...> 
> > > wrote:
> > > 
> > >>Bungard, but since it dates back to the sixties I figure the 
> patent
> > >>protection is meanwhile void. I'm however not experienced, 
that 
> > > 
> > > said I
> > > 
> > >>don't know if a patent is protecting "forever" or if it's only
> > >>effective for some years.
> > >>
> > > 
> > > 
> > > 17 years
> > > 
> > 
> > we had patent discussion long time ago on this group.
> > see message
> > http://groups.yahoo.com/group/Homebrew_PCBs/message/1561
> > 
> > Does the yahoo groups "search archive" feature search the entire 
> hystory 
> > of the messages ? I coulnd't find this message using the yahoo 
> search. 
> > All the messages are stored, but it seems they cannot all be 
> searched. I 
> > had to search for this message from the email folder on my home 
PC.