X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
Date: Thu, 31 May 2012 00:30:02 -0700
From: Colin D Bennett <colin AT gibibit DOT com>
To: geda-user AT delorie DOT com
Subject: Re: [geda-user] Odd Behavior Around Vias
Message-ID: <20120531003002.38be5d00@svelte>
In-Reply-To: <4FC6FDFA.1020001@innocent.com>
References: <4FC6FDFA DOT 1020001 AT innocent DOT com>
X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; x86_64-pc-linux-gnu)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - gator297.hostgator.com
X-AntiAbuse: Original Domain - delorie.com
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - gibibit.com
X-BWhitelist: no
X-Source: 
X-Source-Args: 
X-Source-Dir: 
X-Source-Sender: (svelte) [67.160.113.82]:55294
X-Source-Auth: colin AT gibibit DOT com
X-Email-Count: 1
X-Source-Cap: c2t5bGVuO3NreWxlbjtnYXRvcjI5Ny5ob3N0Z2F0b3IuY29t
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

On Thu, 31 May 2012 01:13:30 -0400
Gus Fantanas <fantanas AT innocent DOT com> wrote:

> I am using the gEDA package from the repos of Ubuntu 12.04LTS.  I 
> finished a layout in PCB, but afterward I had to increase the
> total pad diameter around some vias at the request of the fab
> house.  After I did that FROM THE COMMAND WINDOW, the clearance
> of two vias (which just had the pad size increased) from the
> ground plane SHRANK to accommodate the increased pad diameters.
> The ground plane on that board was connected polygons to minimize
> parasitic capacitances at a couple of spots; the ground plane was
> at considerable distance from each of the two vias, except in one
> direction.  After increasing their pad diameter, the clearance
> region of each via should have "eaten into" the ground plane, but
> that did not happen.

I tested this on my Ubuntu 12.04 install using the pcb program from
the Ubuntu repository (version 20110918-4), and at least with a
quick test, pcb is working right.  I create a via (default
settings: 36 mil copper diameter, 20 mil drill hole, 10 mil
clearance to polygons), draw a rectangle flood surrounding it, and
observe a 10 mil clearance around the via. Select via,
enter :ChangeSize(selected, +2mil).  As expected, clearance gap is
still 10 mil, though the copper diameter has increased to 38 mil.
I tried changing the drill size as well, and it worked as
expected.  It must be some deeper and sneakier bug, unfortunately.

>...
> their pads further) the clearance check from the ground plane
> "woke up."  Pressing CTRL-S on each via to reverse the previous
> increase MAINTAINED PROPER CLEARANCE!

I assume you mean Shift-S to reverse the size change since Ctrl-S
is Save Layout.

Regards,
Colin