From: Robert Baer
X-Mailer: Mozilla 4.75 [en] (Win98; U)
Subject: Re: How to make scales?
Date: Sun, 17 Nov 2002 01:49:02 GMT
NNTP-Posting-Date: Sat, 16 Nov 2002 17:49:02 PST
Organization: EarthLink Inc. -- http://www.EarthLink.net
> On Sat, 16 Nov 2002 00:57:35 -0000, "John Jardine"
> >George wrote in message
> >> As an amateur, I like to build scientific instruments. I'm looking
> >> information on how to produce scales with techniques like these:
> >> - photoengraving on metal (aluminum and brass)
> >> - photography on ceramic
> >> - photography on enamel
> >> Other techniques, suitable for amateurs, are welcomed! :)
> >> These scales should have a diameter of 20 cm about.
> >> Is it also possible to use scales drawn by CAD?
> >> PLease, answer on the NG.
> >> georges
> >CAD (eg Designcad) plus 1440 dpi printer can make excellent scales. If
> >printed on clear film, items such as optical gratings can come out very
> I already tried Google, without success.
> I also made eccellent scales with CAD and I printed them on paper, on
> card, on clear film. I woud like to make scales on metal because they
> are rigid and they last for a long time. Also scales on plastic plates
> could be good. Do you know a technique to do them?
With a negative (clear film was one of your results), one can expose a
photoresist on the (aluminum) metal surface, develop it and then anodize
to "any" color you want.
Multiple colors are possible, and a clear and hard anodize protection
film may be a possible addition.
Alternately, paint can be applied via a silk screen created from the
negative and photoresist.
Application can be via roller using thixotropic paints, or by careful
Some paints then can be baked on afterwards for greater abrasion
Be advised that if you use KPR, then steal some Dichloroethylene
(*not* -ethane); it is a banned substance and is a rather active
degreaser and can be harmful to your skin.
DCE is far superior and less expensive than the developer that Kodak
sells for KPR, and used in a vapor degreaser, lasts a loooong time.
For the el-cheapos, use eggwhite and chromic acid (if i remember
correctly) as the activator, for photoresist.
After exposing to UV, the development is via slightly warm water
(careful, eggwhite is delicate) to remove un-exposed material.
There are various art stores that have silk screen equipment and
various sensitised films and some photoresists.
Look around and ask a lot of dumb questions and select the scheme that
fits you the best.