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Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

From: "Rick Sparber" <rgsparber@...>
Date: 2013-03-20

My gold standard are the dials on my Craftsman/Atlas lathe. My guess is
those scribed lines are around 0.002" wide and the numbers are all perfect.
It was build around 1964 so probably done with a machine. Not much CNC back
then.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew
Sent: Wednesday, March 20, 2013 9:11 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

This picture is certainly helpful, but does raise some questions. I notice
some waviness in the outlines, but I am guessing that may have been
intentional? For a machine tool dial, anything less than narrow, crisp,
straight lines will reduce its usefulness. Normally when I make a dial or
something similar, the width of the line I cut in the metal is in the
vicinity of .001" to .002" -- just a slice made with a sharp tool. I have
doubts about the feasibility of producing consistent, clearly visible lines
of that width by etching around a pattern (leaving the lines embossed) as
Rick is proposing to do.

Again, half the fun of inventing is proving the doubters wrong! I look
forward to seeing what Rick will come up with.