Alt-BEAM Archive
Message #02824
To: beam beam@corp.sgi.com
From: Richard Piotter richfile@rconnect.com
Date: Fri, 30 Apr 1999 09:20:35 -0500
Subject: [alt-beam] Re: was PCB, now cheap drills
Also, beware Radio Shack Etchant and Dry Transfer decals. I could not
figure out why they kept lifting! I could even scratch them lightly, and
they wouldn't come up! It turns out, the dry transfers were EXPANDING!!!
They buckled, and would then lift!!! Anyone know where I can get some
stronger etchant?
Bruce Robinson wrote:
>
> Jacob Booth wrote:
>
> > ... If you keep snapping those tiny drill bits ...
>
> Or, if you're really desperate and don't have a dremel ... Y'know those
> sets of small jewellers screwdrivers? Press down on the top and twist
> the body with the thumb & middle finger? Yep, I used the smallest one
> once to drill several dozen holes. Yeah, I know, a lot of work, but it
> was a holiday weekend and I couldn't wait for the stores to re-open.
>
> It works, but watch out for blisters.
>
> Also, James Niemasik wrote:
>
> > ... use Ferric Chloride or Ammonium Persulvate in crystal (dissolve it)
> > or liquid form. Heat the liquid and put the board in, then agitate it
> > for 5-25 minutes.
>
> I found if you leave the board in the etchant too long, it starts to
> undercut the masking material or artwork. For fine lines this can be a
> pain. A stronger etching solution gets the job done faster and minimizes
> undercutting. Take sensible precautions with the etchants -- most of
> them are toxic.
>
> Regards,
> Bruce
--
Richard Piotter
richfile@rconnect.com
The Richfiles Robotics & TI web page:
http://richfiles.calc.org
For the BEAM Robotics list:
BEAM Robotics Tek FAQ
http://people.ne.mediaone.net/bushbo/beam/FAQ.html
------------------------------------------------------------------------
eGroup home: http://www.eGroups.com/group/alt-beam
http://www.eGroups.com
- Simplifying group communications
Home