It seems that there are a lot of very experienced fabricators in this forum.
I have learned a great deal from reading the posts.

I started laying out boards in 1998, it is not my chosen profession but is
starting to become my chosen profession. I enjoy it very much.  When
I started a old manufacturing engineer gave me a set of guidelines to follow
and something's I am still figuring out on my own. With that said here is my
question to the forum.

Right now I am sending all my gerbers and drills out in millimeters in a 3,5
274x format.

So that means I am calling out things at 1/100,000 of a millimeter. I know
that this has
to be way beyond etching tolerance and what a drill can hold on tolerance.
This is kind
of what I started with. I have begun to change all of my designs to a .05
millimeter grid.
But I still have some old legacy stuff from when I really didn't know what I
was doing.

So my question is what is realistic. At how many decimal places in
millimeters or mills
does it become nonsensical and a waste of time for the guy or program that
has to
round everything off.

What kind of tolerance can a modern drill hold?
At what point does the photo plotter or direct imaging machine run out of
gas?

Once again I have learned a great deal from this forum and would appreciate
any kind of response

Thank You
John Foster

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------