Homebrew PCBs

On Mon, 13 Jun 2005 17:39:15 +0200, derekhawkins <derekhawkins@...>  
wrote:

> Hi,
> Just finished putting together a CNC drilling machine and have now
> stumbled on a problem that I never anticipated....The drilling machine
> appears to be more accurate than the printer used for the PCB
> artwork....Tried both a HP2420 (laser) and Epson 2200 (Inkjet) and the
> results were similar. Is this a known issue with CNC setups?


yes, this is a known issue. lasers have all kinds of distortions.
You can fight it by using non-shrinking media (in case of the laser), and  
separate correction factors for x and y axis.
If your PCB software does not support correction factors make a picture  
and resize it with irfanview (www.irfanview.com).

I got my printer to produce a toner transfer that had non-measurable  
distortion only, so that should be possible.


ST