Electronics Forum / CAD / May 2007

Sounds basically good.
Been a while since I have etched a board by hand. I send all mine out
these days. But from what I remember.

Keep a heat source on the etchant. I think I used to use a 150W flood
lamp.  Most folks try to hang the board up and down, not flat and use a
bubbler, which can be an aquarium air pump with a bunch of pin holes in
the hose to keep the etchant moving.

As for trace and space. In the PCB CAD world we talk in mills or mm so
we would not say 1/16th" trace and 1/32" space we would say 62.5mills
trace and 32.25 mill space.  This BTW is considered huge today.
Using
http://www.geocities.com/capecanaveral/lab/9643/TraceWidth.htm
For continuous 5A and 10c temp rise you can see you need a 54 mill trace
but you are intermittent (you didn't give a duty cycle) so less would
work. If you got room though design for continuous - say 50 mills.

My guess is 30-50 mill is more than enough.  30 mill space sounds good
for hand etching. 10mill trace and space is more "normal" for signals in
a low tech area and you can probably get 15-20 mill space to work with a
decent home made enchant tank if you need the room.

Based on all that if I were you I would go with 50 mill trace and 20-30
mill space.

On 5/9/2007 8:34 PM, The digits of Cat's hands composed the following:

Your use of Usenet
http://www.google.com/search?q=cache:3uMiDBcerS8J:en.wikilib.com/wiki/Usenet+fol
low-Usenet-customs-and-*-rules+*-a-service-for-*-*-*-*+hide-the-fact-*-*-*-they-
are-*-on-Usenet+concerns-*-*-*-*-about-the-Google-interface+what.is.wrong+*-*-*-
*-*-*-*-*-*-*-*-*-*-is-now-legendary+*-*-savvy+Google-cannot-muster-*-*-*-*-*-*-
*-*-*-*-*-*-*+*-*-policed&strip=1
needs improvement.
If you feel *compelled* to ask the same question
in MULTIPLE newsgroups, *this* is the prefered technique:
http://www.google.com/search?q=cache:qHhBKJ-sXKYJ:en.wikipedia.org/wiki/Cross-po
st+adequately.answered+corrected+with.commas+individually+Disclaimers+*-*-*-mark
ed-as-Read-in-ALL-*-groups+Newsgroups.line

Your technique
http://groups.google.com/groups/search?q=Beginner.looking&enc_author=OrLpAxIAAAC
Gd0H-OBIFtHzCTseL62EG8rhlH0Pnl47z4AZhN98BFg&scoring=d&filter=0
is selfish and inefficient.

The last half of this thread explains WHY
and fleshes out the (more acceptable) cross-posting paradigm:
http://groups.google.com/group/sci.electronics.basics/browse_frm/thread/7b7c0624
331012bb/3958f18673b5f374?q=EVERY-group-*-*-*-*-*-*-*-*-appear+*-proper-answer-*
-*-*-given+much-easier-*-*-*-*-*-*-*+*-frowned-on+*-correcting+*-Followup-To-*+*
-*-_perfect_-*-*-*-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-polite-*-mention-*
-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+mark-*-*-*-*
-all-*-groups+*-*-*-*-two-groups-*-*-aren't-*-different

The last post in that thread hints at why (clueless) Google Groupers
are so reviled by the majority of Usenet readers (who use a
"newsreader").

I would have put the board out to a professional company to make.
Home made boards are crap.