default_smd was too big for low density boards

        sprintf( rule, "(clearance %.6g)", clearance+safetyMargin );

        sprintf( rule, "(clearance %.6g)", clearance+safetyMargin );

        rules.push_back( rule );

        rules.push_back( rule );

        // On a high density board, a typical solder mask clearance will be 2-3 mils.

        // On a high density board (a board with 4 mil tracks, 4 mil spacing)

        // a typical solder mask clearance will be 2-3 mils.

        // This exposes 2 to 3 mils of bare board around each pad, and would

        // This exposes 2 to 3 mils of bare board around each pad, and would

        // leave only 1 to 2 mils of solder mask between the solder mask's boundary

        // leave only 1 to 2 mils of solder mask between the solder mask's boundary

        // to the edge of any trace within "clearance" of the pad.  So we need at least

        // to the edge of any trace within "clearance" of the pad.  So we need at least

        // 2 mils *extra* clearance for traces which would come near a pad on

        // 2 mils *extra* clearance for traces which would come near a pad on

        // a different net.  So if the baseline trace to trace clearance was say 4 mils, then

        // a different net.  So if the baseline trace to trace clearance was say 4 mils, then

        // the SMD to trace clearance should be at least 6 mils.  Also add our safetyMargin.

        // the SMD to trace clearance should be at least 6 mils.

        sprintf( rule, "(clearance %.6g (type default_smd))", clearance + 2.0 + safetyMargin );

        double default_smd = clearance + safetyMargin;

        if( default_smd <= 6.0 )

            default_smd = 6.0;

        sprintf( rule, "(clearance %.6g (type default_smd))", default_smd );

        rules.push_back( rule );

        rules.push_back( rule );

        /* see: http://www.freerouting.net/usren/viewtopic.php?f=5&t=339#p474

        /* see: http://www.freerouting.net/usren/viewtopic.php?f=5&t=339#p474