I've used hole saws myself.these are hard to find in 57mm (2.25") and 80mm
(3.125") but again... www.mcmaster.com
had these and you won't find these sizes in the Home depot or other common
local stores....though these were expensive...
I use the hole saws then placed metal instrument hole reducers (I have
these) over the hoe and finished with drum sanders (you can buy these at
local stores) for final fitting.I also use a dremel type tool with small
sanding drums for the cutouts for altimeter adjusters etc..all these tools
work amazingly well in Phenolic sheets.I am sure good sharp router bits will
also work well though I haven't needed to sue these....having a good drill
press is necessary to use the hole saws though and a real aid with the drum
sanders as well..gives you a good excuse to own these tools )
tim
"Todd Pattist" wrote in message
...
"Tim Mara" wrote:

really depends on how large the panel is and how well it's supported, but
typically the 1/8" is plenty.......but use the fiberglass material, not
the
canvas or cotton, it is stronger

Thanks. When I've made panels, I've used a router and
template. I mark the center of the instrument holes I want.
Then I use an undersized hole saw to get close to the
instrument hole size needed, then clamp the template to the
sheet, drill the mount holes through the template mount
holes, then use the router to enlarge the undersize main
hole and get good clean edges and the final exact shape and
size instrument hole needed. Will a router give a good
clean edge on Phenolic sheet?
Todd Pattist - "WH" Ventus C
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