Re: DIY probing

Message: 5
Date: Fri, 02 Nov 2001 10:53:29 -0500
From: ccs@...
Subject: Re: Re: DIY probing

> Seems to me your project would be much simple, quicker and cheaper to
> accomplish using RTV rubber to cast a mold of the inside if the horns'

bell.

Unfortunately folks aren't going to let me smear mold release on their
200+ year old antiques made of brittle deiznicified brass and then
fill them with a material that releases acetic acid when it cures...
If I were going to do a casting I'd use something in the way of a
plaster.

The default method is to cut a wooden template that fits the inside and
then push modeling clay around the edges to get the countour more exactly,
then trace this.

Chris

[While I certainly don't want to discourage anyone from building a CNC
digitizer, if I really wanted to get the inside curve of a trumpet bell I'd
try a molding contour gauge, which finish carpenters use to cope in the
profiles of wood moldings that meet at an angle. These are a simple device
with a row of straight pins that lock and hold a shape. All silicone rubber,
by the way, doesn't exude acetic acid; that's just the single-component
caulking material. The two-component types are a lot easier on parts-
there's even a kind that dentists use inside people's mouths. It would be
better than plaster, in terms of damaging an object being molded. ]

Andrew Werby
www.computersculpture.com