How to produce Imperial (Inch) Gerbers?

Manufacturing
1

Is there any way to create inch Gerbers with KiCAD? The manufacturer I’m using tends to use inch endmills for cutting and slotting operations and I’m concerned about using a metric conversion of the minimum tool size.

Looking into the bug reports, it seems as though the opposite issue was the case here: https://bugs.launchpad.net/kicad/+bug/1295051.

I’m using bzr6337, can someone with an earlier version (or some older gerbers) share what unit theirs are in? This may just be an issue with the Format 4.6 (inch) missing from the dialog.

2

Currently I’m running BZR6097… tried to get inches setup in a mm project (except for starting a brand new schematic+board) it’s always plotting %MOMM*%

I have some gerbers from other projects from github/etc. too that I checked for you:
DEC/2013 (stable) … %MOIN*%
JAN/2014, BZR4027 … %MOIN*%
JUL/2014,unknown … %MOMM*%
AUG/2014,BZR5060 … %MOMM*%
JUL/2015, BZR5935 … %MOMM*%

And then there are gerbers, probably from Eagle which don’t have that field at all and rather go like this:

%OFA0B0*%
%FSLAX24Y24*%
%IPPOS*%
%LPD*%
%AMOC8*
..

Afaik, even mm specified milling/drilling is being rounded to the next 0.05 mm, as they don’t have every value under the sun, no?
What kind of discrepancies are you concerned about? Have some examples for us please?

Must be some odd fab house in the US then?
Everyone working for the military or space over there is metric or can do it… and luckily the Chinese converted to metric a long time ago, which covers the very cheap boards.

3

Gebers used to be generated in imperial only, Kicad devs decided to make it metric only now. Wouldn’t be my choice.

I guess if you have problems with the manufacturer, you will have to change your manufacturer - or change CAD tool. I’m really hoping that the cheap fab houses I use can cope otherwise I will have to go back to 4022, or some other tool.

4

@bobc
you can always make a copy of your actual board file and open it in 4022 version…
The file has to be edited in two points, but then you can open it correctly in 4022 old stable