Homebrew PCBs

Mike Young wrote:

>In the freebie Eagle, is there a way to print, for toner transfer, more than 
>one image per page? I'm trying to maximize use of each toner transfer sheet 
>while keeping the passes through the printer to a minimum. Exporting a 
>monochrome TIF for top/bottom/screen and then panelizing in Photoshop, I can 
>already see, will get very tiresome (not to mention error prone).
>
>Exporting monochrome images to the clipboard is a flabbergasting exercise. 
>It puts a gray half-tone screen on the image.
>
>So far, I have a PS script to invert, mirror, and extend the canvas for 3 
>side by side copies. The script to panelize vertically will be just as easy. 
>But isn't there a better way?
>
>Likewise, I imagine I should be able to script Eagle to export 
><filename>TOP.tif, etc., with the appropriate layers, but I'm not that 
>sophisticated yet. Any tips on how to do this? Do you fancy sharing your 
>favorite scripts?
>
>Unless, of course, there's a more direct way. Like, File|Print would be 
>nice...
>
>Last, is there a reason to export with finer resolution than the printer 
>dpi? I've been exporting 2400 dpi for the LaserJet4, but not sure that
>
>
>  
>

  Not easily from within Eagle Free.  Cut your sheets up, set it to top 
left or top center, and feed in for only one board when you need it.  
Mine's set to top center, and I just stick it into the HP6L's envelope 
feeder and things go well.

  If you really need whole sheets, learn to export your gerbers, and get 
GC-Preview and GerbMerge.  GerbMerge takes a bit to install Python and 
needed extras and get it running, but once going it is very nice.  Align 
all your boards to the closest to 0,0, put a dimension layer box around 
the board, make it export with the boundary layer name that GerbMerge 
needs, and things go very well.  Extremely nice to be able to easily 
place multiple copies where you want by listing the board several times 
and giving the coordinates etc.  A bit manual in editing the placement 
file etc, but still is very nice in general.  The auto placement does 
well enough really for rectangular boards, but odd shapes need manual 
placement to really pack it in while keeping ok spacing.  You'll be glad 
to know it if you ever order from some of the places that do full 
panels..  There are some other free programs besides GerbMerge that do 
merges, another could be better.  Stopped looking after GM was running 
fine, didn't see any others that looked better in the mean time.

  Plug in relevant terms into google for how to do the Eagle exporting 
and scripts.  It's all too popular, so there are web pages and message 
board messages explaining how to do almost everything   Much more likely 
to be found off list than on, and even if no one has exactly what you 
want, it's fairly trivial to make your own jobs once you've looked at a 
few.  Start by finding and testing the gerber/excellon jobs, they're the 
best documented jobs on the web because they're the most used. 

  But for sure GerbMerge or similar and GCPrevue are probably the best 
to learn.  With gerber/excellon it'll take input from about every CAD 
program, and let you panelize like you want and check the output.  Then 
all you need to know about any other CAD etc is simply how to output the 
Gerbers, which is usually easy.  Just is what I'm using, I like it 
fairly well so far..

  The taping and cutouts also work well, as mentioned by others.  Very 
good to use up small pieces for small boards, if less than 3-4 inches 
your paper can be out of one roller set without getting into the next 
rollers, and get stuck in the printer..

  Also, GCPrevue has an option to flip the board, and view from bottom.  
I did this accidently first, but if you import the solder layer twice, 
then component layer twice, you can assign the top of a layer one color, 
and the bottom of the same layer another color.  It's good to have the 
top layer one color, then the bottom layer another, slightly brighter, 
to glow through and see it better.  Then, assign other colors, so when 
you flip the board, the bottom (now on top) is darker and the top is 
lighter.  Very good to see the board from the bottom sometimes, really 
Eagle needs this built in, would be trivial to swap the X axis and even 
work from the bottom not just view.  Could be there, but I haven't seen 
it, not that I've looked hard for it..

http://www.superference.com/images/PCB/PCBpanel2.jpg

Gives an idea of GerbMerge/GCPrevue, with resolution changed to protect 
the innocent :)  Just blow it up a bit, you can still see the general 
layout well enough..

Alan