No one makes the round type that I know about but I'm about too ,they will be 3/8" thick or 1/2" thick ,not sure on that yet but it looks like 1/2" because I have used the 1/2" plastic stock on one of the router tables I have now and it's great, it will hold any router I bolt to it with NO sag at all and it's FLAT.
They will have the snap in part to hold the Porter Cable type brass guides, I think I going to use the standard Porter Cable base plate (black ones )that comes on all PC routers, I have a stack of them that should cut the cost a bit but they are cheap at Rockler Tools ,all I need to do chuck up a Fly Cutter/Hole Saw and put in a 4 1/2" hole to hold the PC base plate.
They should work out fine ,they will have a dowell pin in the table top and a 1/4" hole in the base plate to hold them from turning once they are in place.
Round holes are easy to put in unlike the ones needed to hold the normal 11" x 11" or 9 1/2" x 11" router table plates.
No templates or sticks needed just a small 1/8" hole to hold the Cir.jig in place when the hole is cut out.
I'm going to use a 3/4" lip to hold the round base plates in the top of the new round table that should give me room the to drop any size router in the hole .
The plates are going to be 11" in dia. maybe 12" but I think I'm going to stick with the 11" ones in that way I can still use all the Oak-Park jigs in the same way.
Something like the one below but ROUND ▼ Router Base Plate.see snapshot
I have made several router tables but never with a round insert. I have been reading about them lately and they seem like they would work well. Has anyone went this route. I am thinking about an aluminum or steel.
Pics would be great.