I've been in the glass industry for the past seven years and in my spare time I mess around with the cnc engraving and so on, I don't actually have an engraving bit but I use a diamond embedded router which works well always with water for coolant otherwise it just burns with the heat, and an even surface is crucial. unfortunately I don't have any pics from the work by the router, but I do have some pics of some brilliant cutting I've done and so on.
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http://weekendoutdoors.awardspace.co...20waterjet.htm
I also have a site where I post free creative dxf files
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http://flashanims.awardspace.com/
I don't charge for these files but if you want to earn me some beer money ha ha
you can click on an ad or two they are relative adds so they lead to interesting sites. also being as this is a hobby for me if anyone has a request I'm usually happy to draw up a dxf file in my spare time and post it.