I've printed directly from the PCB software, and also from GC-Prevue using the Gerber files from the PCB software. The output is identical in either case. I don't believe Ultiboard has any ability to scale the output Gerber files.
Now if I had the GC_Prevue Plus ($495) then I believe that would allow me to scale everything in only one direction (though whether it would allow fractional percentages I don't know).
Regards,
David Partridge
-----Original Message-----
From:
Homebrew_PCBs@yahoogroups.com [mailto:
Homebrew_PCBs@yahoogroups.com] On Behalf Of Andrew
Sent: 06 April 2011 15:42
To:
Homebrew_PCBs@yahoogroups.comSubject: [Homebrew_PCBs] Re: HP Laserjet 4050 prints over-size
David,
What software are you using to generate the image? Many have the ability to scale the output in very fine amounts. E.g., Kicad gives the option to adjust the X and Y scales independently down to 6 decimal places. (I have trouble believing that one can actually obtain or use that level of precision, especially with toner transfer, but ...)
This may be what you are referring to when you talk about the printer driver only allowing whole percentages, but I wonder if perhaps you are generating the image from the PCB software, and then trying to scale it when you print -- as opposed to having the PCB software do the scaling.
--- In Homebrew_PCBs@yahoogroups.com, "David C. Partridge" <david.partridge@...> wrote:
>
> I just got a 36x2 way card extender type edge connector, 0.156 pitch to fit the card extender PCB I made with toner transfer printed with my HP Laserjet 4050.
>
> I found that the PCB I so carefully created in my PCB design package has ended up slightly oversized - over the 36 ways the distance from first to last should be 5460 mils and is shown as such in the PCB design software. The finished PCB is larger at 5490 mils over this distance, which doesn't sound a lot, but that's about 0.76mm which isn't a trivial error.
>
> The whole board should be 8.1875" (207.9625mm) but the printed outline is actually 209mm. So call that a 1mm error which is HUGE.
>
> This works out to be about 1.005 times the size it should be.
>
> In this case, there's (just) enough leeway for the board to still work as a card extender without things shorting or failing to connect, but in general this level of error is a disaster.
>
> The printer driver won't scale except in full percentage points, and while 99 percent is closer to 99.45% than 100%, it isn't right.
>
> Has anyone worked out a good solution to this problem.
>
> HELP!
> Dave
>
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