PCB design for guitar amps

[Amptroll]

Kevin and the guys,

     I think metric is the way to go, since most part dimensions on the various vendors websites and the datasheets is in metric.  Also in any engineering setting when working with others especially the scientist like the physisists I have encounter strictly use metric not SAE unless its in the american automotive design, there are those that still use SAE.  Don't most pcb manf. houses use metric

    I grew up under the "inch" system, so my mind gauges 3D translations in "inches".  The ECAD I use allows me to toggle between metric and mils, which I do often, so I can visualize the dimension before I enter it into the ECAD.  This really comes in handy when I create components.  The component wizards when opened are always defaulted to metric, which also hints towards the use of mm and such.  We are lucky that most still use decimal degrees and not hours, minutes and seconds for angular measure.
Take care everyone and peace,
Rob

Hi Guys

How old-school am I? Or you?

I still use inches when laying the board even though every component you buy today has measurements in mm. When you make the library part, you can either convert the dimensions into inch and go from there, or lay the part out on a metric grid and let the board editor deal with it when you are laying traces.

I have hundreds of projects laid out on an inch grid and ponder changing to metric (as I really should do some time). The old projects are unaffected by doing new projects and parts in metric, until you go back to one of those projects and add a new part, or a new metric version of a part. The only issue will be whether Eagle thinks the pins are connected or not on the board, in which case you just make the grid small enough that it gets the trace centre as close as it needs for a "connection".

My version of Eagle plots in mils by default. I try to remember to switch to metric whenever I start a new board.