kicad-developers team mailing list archive

[Brian Sidebotham <brian.sidebotham@xxxxxxxxx>]

On 17 October 2014 14:10, Wayne Stambaugh <stambaughw@xxxxxxxxxxx> wrote:
> On 10/17/2014 8:44 AM, jp charras wrote:
>> Le 17/10/2014 14:22, Mark Roszko a écrit :
>>> Alright, I've played around. It appears there is many CAM/gerber
>>> software that cannot handle G75 arcs that are full 360 degrees. I
>>> tested this with the board from Jon and the 1 pin test board from
>>> Nick. If I generate 359 degree arcs, the 3d viewer is happy and draws
>>> good circles. If I generate 360 degrees then the arcs disappear/screw
>>> up.
>>> As far as I can tell, the math is right for the arcs regardless of 360
>>> or 359. I think it's because the start point == end point for a 360
>>> degree arc, that some viewers may break down due to their graphics
>>> libraries.

Well done figuring out the cause of the issue Mark!

>
> Do we really want to be in the business of working around other peoples
> broken software?  I really don't want KiCad to be part of that world.
> It's one of the reasons I am willing to work on KiCad for free.  While I
> appreciate your effort, this is something I would not commit unless we
> are violating the gerber specification which appears not to be the case
> if JP is correct.  What we should be doing is sending high quality bug
> reports including references to the gerber specification, screen shots,
> files that cause the problem, etc. so the developers of the various
> broken gerber viewer apps and make it their responsibility to fix their
> code.
>

No we don't! This is a clear-cut problem with CAM350. To be fair to
them, CAM350 V9.5 was released in 2007 and there have been a lot of
updates since then. I expect a newer version to have fixed the issue
seen here.

It is a clearly documented case in the Gerber specification and I
checked the gerber output of KiCad which is producing exactly what it
needs to in this case.

I'm more surprised that the fab house didn't see the issue with the
silk screen, it's obviously wrong. But to keep the costs low these
days they're not far off fully automated, so these things no longer
get checked.

Best Regards,

Brian.