Homebrew_PCBs

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

I make very small boards so I don't want to run a full page of Toner
Transfer paper.

My technique is simple:

Print the final image on a sheet of regular paper.

Cut out the image.

Tape a piece of toner transfer paper over the hole, attached at the
leading edge with an address label.

Run the page back through the printer.

My printer has a problem printing on a double thickness of paper,
that's why I cut out the page. If your printer doesn't have this
problem then just tape a piece of transfer paper over the printed
image made with the test pass.

On Thu, 03 Nov 2005 15:18:17 +0100, bob_ledoux <bobledoux@...>
wrote:

> I make very small boards so I don't want to run a full page of Toner
> Transfer paper.
> My technique is simple:
> Print the final image on a sheet of regular paper.
> Cut out the image.
> Tape a piece of toner transfer paper over the hole, attached at the
> leading edge with an address label.
> Run the page back through the printer.
> My printer has a problem printing on a double thickness of paper,
> that's why I cut out the page. If your printer doesn't have this
> problem then just tape a piece of transfer paper over the printed
> image made with the test pass.

I have found on all printers i have that thicker paper means less toner.
So, if you already turn it up all the way you don't want a second layer,
cut it out as you say.

I've also bought the lightest weight paper with the right coating, to
increase the toner amount.


Me personally, the inkjet paper i use is so cheap it does not warrant the
effort, however i do cut it into half sheets, and i do panelizing on
almost all boards. (sadly my pcb software can not print top/bottom/legend
besides each other, only of the same kind, and i am to lazy to manually
put it together in a picture editor.

ST

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