Hi Lum,

In Fablink, under Change Artwork Format, set the output
format to 4 decimal places rather than the default of 3
(provided your units are inches). 3 decimal places only
gives you 0.001 resolution Gerber files so traces routed
on a smaller grid or no grid will snap to the nearest 0.001.
This can produce 0.005 spacing with 6/6 rules even though
you will not see it in Layout. For more Mentor specific info
check out the MUG pcb_sig at mentorug.org

Regards,
Roy
Roy H. Beckman, C.E.T.
Senior PCB Designer / System Administrator
Harris Canada, Inc.
6732 - 8th Street, N.E.
Calgary, Alberta, Canada T2E 8M4
Phone: 403-295-4758
Fax: 403-295-4622
email: [log in to unmask]

-----Original Message-----
From: Lum Wee Mei [mailto:[log in to unmask]]
Sent: Tuesday, June 22, 1999 10:35 PM
To: [log in to unmask]
Subject: [DC] Inconsistent Gerber Output


I have a question regarding Gerber output. Most of our designs are done
with 6/6 (trace/spacing). One one occassion, our regular PCB vendor
called us up and inform us that they found some 5/5 on a particular
layout. However, when we call up the layout on our workstation with grid
at 1mil setting, we found that the so-called problem area to be a
perfect 6/6.
Recently, this problem cropped up again with another new PCB vendor.
Once again, our layout show a perfect 6/6.
Can anyone throw me a light on what could be the problem. My Mentor
Graphics rep mentioned that it could due to the CAM system used by our
PCB vendor.
Thanking in advance.
Regards.