Homebrew PCBs

Moore wrote:
> Is anybody using toner transfer to do double sided boards?  If so how?
> 

   I do it all the time.  Print out both pages as normal, remember top 
is mirrored bottom is not to match correctly.  Hold them up to light and 
try and make sure they're both good.  Pick two holes near opposite 
corners, so the line between the alignement holes is as long as 
possible.  Iron first side on as normal.  After peeling drill those two 
holes, centered as well as possible.  Then by hand drill the same two 
holes in the other paper.  Lay that paper down on the board for ironing, 
and stick two drill bits in the holes in the paper and board to align 
it.  Flatten and hold the paper, ironing from one of the other corners 
toward the center until it's stuck well to the board.  Remove the drill 
bits and finish ironing as normal.

   Even if your holes in the board and paper are a bit off center, just 
shift the second paper a bit so the errors match, there's a little play 
with the bits through the holes.  With just a little practice, you'll 
get excellent results.

   Also I tend to make my via holes a bit larger, and when drilling by 
hand I drill the hole to the side of the via and then bend a small wire 
over to it.  But I also have a CNC drilling machine now so don't do much 
hand drilling now.  Not worth setting up and aligning for just the two 
guide holes though..

Alan