Nice write-up Tim and good work Walt!
I'm wondering about the rough edges, and the timber layers, about 40 years ago I had to cut a lot of holes in sheet glass (we wanted the glass discs) and we used a short length of 15 mm copper tube chucked in the drillpress. The glass was clamped down and a 'well' made with plasticene - play putty - the well filled with paraffin - kerosene- and very fine carborundum powder - can't remember the grit size. The results were perfect, the drill press handle had a length of string and a weight on it for constant pressure and the whole thing left running while we drank tea
Not a quick method by any means, but the results are good.
I'm sure there must be a more modern version now - maybe the same setup as yours except no teeth, just carborundum - a bit of cutting fluid in there would help too.
Maybe a cnc waterjet even if you know a friend who has one (as if
)
Thanks again for all the info.
Cheers
Neil