Dick, > Then why are you here? What is your point? Make the patch contribution, all > fields if > you want, and I will personally give it extra consideration. > > If you are here to only create mischief and take shots, we can do without > that. > > Contribute, do it like a team player, or go away please. > > This is your best chance, right here, right now, to be taken into this team > or be shut out. >
The changes are on my kicad-brian branch on launchpad from a year ago. Pull away. I'll also take this opportunity to explain to you why the internal unit is a bug and increasing it is a bug fix and not a feature: When I was laying out CBGA fields with metric spacing in kicad, kicad moved every pad and via over to the next decimil grid position. This causes several errors: 1. No pad is in it true position on a metric grid and is no even in the correct position to a diagonal. 2. When placing vias between pads, each via was also off the metric grid, sometimes adding in error to the pad placement. 3. 45-degree dogbones between pads an vias could not make a 45-degree angle (because pads and vias are not on the diagonal, making a long dogbone and a little 1 mil jog segment between the one end of the dogbone and the via or pad. Unlocking the 45-degree track does not solve the problem because the round-off jogs the endpoint of the track and the 1 mil fragment reappears. 4. Pads are misplaced with respect to their drill holes. 5. Pads and vias must be dropped from 12 mil to 11.8 mil to avoid DRC errors. Tracks must be dropped from 5 mil to 4.8 mil to avoid DRC errors. (The DRC using integer math rounds the other way from the grid error at points.) 6. Fabricator says we do 5 and 5 and to meet annular ring requirements pads must be increased to 12 mil and tracks increased to 5 mil; however, when that is done, they all fail DRC on the fabricator's CAM tool. 7. The 5000 copper features on the board increase to about 7000 due to the little 1 mil segments that cannot be gotten rid of. Fabricator charges by number of copper features (because the number increases the run time and memory requirements of the CAM tool). So I have 2000 features too many and have to pay for 4 and 4 instead of 5 and 5. Please understand that the Gerbers given to a manufacturer represents design data and has nothing to do with fabrication limits. Round-off errors in the design data simply add to the manufacturing tolerances making everthing worse. CAM systems are quite accurate in their calculations of DRC on design data. 3.5 metric Gerber data (3.6 is better) is required to place everything in its true position on both an imperial and metric grid. PCBNEW internal unit must be a nanometer so that vias in a metric BGA pad field are placed in their true design position. BTW, the 0.1-degree angle doesn't cut it either. This is why when I see someone take it upon themselves to change the internal value to nanometers and get jumped on for how the went about it rather disconcerting as a user. Because, from a user perspective, I don't care whether int was overloaded or macros are strewn everywhere: without a precise internal unit, kicad is useful only for laying out dimmer switches. Make the unit a nanometer, or better. Make the angle 1/1000th of a degree, or better. Otherwise these same problems will result on some board. --brian -- Brian F. G. Bidulock � The reasonable man adapts himself to the � [email protected] � world; the unreasonable one persists in � http://www.openss7.org/ � trying to adapt the world to himself. � � Therefore all progress depends on the � � unreasonable man. -- George Bernard Shaw �
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