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08-25-2022, 12:38 AM
Hi Guys
It is very telling about the state of the PCB manufacturing industry back in 1985 that INCH was still king when Eagle, PCAD, PSPICE and most of the other CAD-CAM software was first being developed. Europe was fully metric yet Cadsoft in Germany was writing Eagle to lay out schematics and boards on a 0.1" scale. Was this influenced solely by the fact that the chips they wanted to place on boards were designed in the USA with 0.1" lead spacing? Maybe.
A machinist told me in the 1990s that all the numerically-controlled machines in his shop worked internally on decimal inches. Was this a legacy of US influence over manufacturing equipment? Maybe.
The US and other Western countries basically handed over manufacturing practises, equipment and market to Eastern countries, who adopted the inch-based NC machine designs, but are those still inch-driven today? Most Chinese PCB houses ask for metric dimensions, but this alone does not indicate reliably whether their machines are metric inside.
With the software for board and mechanical design, you can change the scale and the unit at will for specific steps of your layout process, as other threads here detail. Since I began these threads, I have switched to Eagle 6.3 out of necessity. My offline computer died and I had a second PC to take its place, and this one has a relatively rare 64-bit version of XP.
All of my design, writing and customer data is processed using offline computers. This is the best way to assure security of the data.
It is very telling about the state of the PCB manufacturing industry back in 1985 that INCH was still king when Eagle, PCAD, PSPICE and most of the other CAD-CAM software was first being developed. Europe was fully metric yet Cadsoft in Germany was writing Eagle to lay out schematics and boards on a 0.1" scale. Was this influenced solely by the fact that the chips they wanted to place on boards were designed in the USA with 0.1" lead spacing? Maybe.
A machinist told me in the 1990s that all the numerically-controlled machines in his shop worked internally on decimal inches. Was this a legacy of US influence over manufacturing equipment? Maybe.
The US and other Western countries basically handed over manufacturing practises, equipment and market to Eastern countries, who adopted the inch-based NC machine designs, but are those still inch-driven today? Most Chinese PCB houses ask for metric dimensions, but this alone does not indicate reliably whether their machines are metric inside.
With the software for board and mechanical design, you can change the scale and the unit at will for specific steps of your layout process, as other threads here detail. Since I began these threads, I have switched to Eagle 6.3 out of necessity. My offline computer died and I had a second PC to take its place, and this one has a relatively rare 64-bit version of XP.
All of my design, writing and customer data is processed using offline computers. This is the best way to assure security of the data.
