I'm building a variation of Norm's Router table and have a corain sink cut
out from my laundry room sink. Its big enough to make three inserts. has
anyone used corian?...

James,

I have not used corian for a base plate, but my builder took that same
cut out from our sink and cut it into 2 cutting boards (approx. 18" x
18"). They put rubber feet in each corner and I have noticed that it
has bowed. If you're going to make a router insert out of it, try to
keep the dimensions down.

Chuck