kicad-developers team mailing list archive

[jp charras <jp.charras@xxxxxxxxxx>]

Le 16/02/2016 17:55, Andy Peters a écrit :
> 
>> On Feb 16, 2016, at 1:02 AM, Lorenzo Marcantonio
>> <l.marcantonio@xxxxxxxxxxxxx> wrote:
>> 
>> On Tue, Feb 16, 2016 at 12:40:34AM -0700, Andy Peters wrote:
>> 
>>> I understand, I was just trying to figure out why they rejected
>>> the files. After some back and forth e-mail, I think it’s because
>>> they’re using an ancient version of Cam350 that doesn’t
>>> understand Gerber Extended Attributes. (I never did get a reply
>>> to the request: “Send me your actual official requirements!”)
>> 
>> My 2 (euro)cents:
>> 
>> - I confirm that CAM350 is one of the suckiest piece of gerber 
>> processors, however is also the only one that many people can
>> afford :P I had the same issue (IIRC I was one of the people
>> requesting 'optional' attributes)
> 
> Let’s be honest. They’re using cracked versions of Cam350.
> 
>> - Forget about MOIN (imperial) gerbers unless you have a working 
>> solution for rounding zone edges to the 'right' direction
>> (discussed a couple months ago)
> 
> the only reason I thought about exporting inch-based Gerbers is
> because all of the “suggestions” made by various people about how to
> get them in a format Seeed likes  mentioned “inches.”
> 
> Anyways, I thought it odd that I couldn’t change the units for the
> Gerbers from metric to imperial, which seems like a bug.
> 

Seeed does not say the Gerber files must be in inches.

I see absolutely no reason to generate Gerber files in inches.

If you are thinking generating Gerber files in inches is just a matter
of unit conversion, you are wrong.

Pcbnew internal units are nanometers.
Generating Gerber files in mm in x.6 format do not create truncation.
Generating Gerber files in inches x.6 format will slightly change
coordinates (unless using higher precision format, but if the X2 format
is not yet supported, be sure high precision format is not supported).
Slightly changing coordinates means changing polygon corners positions
in filled areas, and creating sometimes (read often) self intersecting
polygons, which are forbidden in Gerber Files (Although when happens, I
did not see issues).
Therefore you have to rebuild polygons using new coordinates to avoid that.

-- 
Jean-Pierre CHARRAS