Homebrew PCBs

Stefan Trethan wrote:

>
>Actually, when i suggested the moving air nozzle was thinking not of a  
>pendulum, but of a rotating tube, like a barber's pole you know, with  
>holes in a spiral pattern. At any time only one or few holes are on top,  
>spewing air, but there is a total of very many holes in different places.  
>Just an idea....
>  
>

  Yes, got that part of the idea but a simpler motion system will be 
easier..

>Might be easier to make the pole a bit shorter than the tank, and not  
>rotate it but instead slide it back and forth with a magnet one the  
>outside.
>
>  
>
  But that will require something else to do moving, and rotary to 
linear motion.

  Tank, then a pole on the outside center of the long side of the tank, 
that's 2x the height of the tank, so the hinge point is at 1x more above 
the edge of the tank.  Longer arm to make the sweep at the bottom more 
linear.  Say a 1.8X arm, with a stone at the bottom, and air tube to the 
stone.  Driving link and motor attach near the hinge, well out of the 
etchant.  Use a flat arm, flatten the tube a bit as it passes the lid, 
and have a decent raise/lower system for the board, and you can leave a 
top on the tank.  Just a slot for the arm/tube to sweep, and a slot to 
load the board through..  Clear PVC etc on each side of those slots, to 
close it except when the arm or board are right there, and you will have 
near zero evaporation, and almost never open the container.  Just slot 
load the board and etch.  No tube thing to build, just get a stone and 
some line and make a fairly simple pendulum and attach a motor to it.  
Can be greatly linearized with a little mechanical mixing, or a stepper 
etc could make it near perfectly linear.  So simple we should have come 
up with it talking about the rotary etcher and other types last year, 
duh if a stone is too uneven sitting there then move it..  Obvious 
concept, just didn't even cross my mind at that time..

  Wait till you see some video of my little manufacturing plant for 
rounding my boards and applying the LEDs, I think it's rather neat.. :)  
So nice to have all the flying dust stay inside a ziplock bag..  Now to 
automate my iron and solder feed and feeding the LEDs, may as well let 
it build the board for me while I go have a beer.

Alan