<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=US-ASCII" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 9.00.8112.16457"></HEAD>
<BODY style="FONT-FAMILY: Arial; COLOR: #000000; FONT-SIZE: 10pt" id=role_body
bottomMargin=7 leftMargin=7 rightMargin=7 topMargin=7><FONT id=role_document
color=#000000 size=2 face=Arial>
<DIV>Hi Neil</DIV>
<DIV> </DIV>
<DIV>Thanks for your book suggestion. My background is in RF electronics, not
mechanics so my suggestions may not always be entirely practical!</DIV>
<DIV> </DIV>
<DIV>What would be needed is a clean original from which to make the mould. Then
a choice of moulding material that could be cast and would be sufficiently
strong to take the mechanical stresses. The centre part does not need to be
clear but the outer ring does.</DIV>
<DIV> </DIV>
<DIV>I have a desk top decorative item that has a collection of clock
parts cast in a clear block which looks like acrylic or polystyrene.
Feels very hard but no idea how it would stand up to stresses.</DIV>
<DIV> </DIV>
<DIV>Do we have a mechanical engineer in the forum that could provide some
ideas? I suspect that the market for these is significant.</DIV>
<DIV> </DIV>
<DIV><FONT lang=0 size=2 face=Arial FAMILY="SANSSERIF"
PTSIZE="10">73<BR></FONT><FONT lang=0 color=#0000ff size=4 face=Arial
FAMILY="SANSSERIF" PTSIZE="14"><I><BR>Bob</FONT><FONT lang=0 color=#000000
size=2 face=Arial FAMILY="SANSSERIF" PTSIZE="10"></I><BR>Bob F Burns<BR>C Eng,
FIET, MSE<BR>Amateur Radio Callsign: G3OOU<BR>Registered RSGB
Instructor<BR>G-QRP Member No: 6907; Zone: 14, QRA: IO91WH; WAB:
TQ25<BR>Secretary of Crystal Palace Radio & Electronics Club: <A
href="http://www.g3oou.co.uk/">www.g3oou.co.uk</A><BR>Technical web site: <A
href="http://www.qsl.net/g3oou">www.qsl.net/g3oou</A><BR>Follow G3OOU as
@BobFBurns on Twitter </FONT><FONT lang=0 color=#0000ff size=2
face="Comic Sans MS" FAMILY="SCRIPT" PTSIZE="10"><A
href="http://twitter.com/BobFBurns">Http://twitter.com/BobFBurns</A></FONT></DIV></FONT></BODY></HTML>