At what stage should the sound hole be routed?

I'm working on the soundboard of my latest project, a pineapple concert with a sitka spruce soundboard. I have just completed the rosette and the the top is now sanded down to 2.5mm. Should I cut out the sound hole now, or later, after the top is attached to the sides? I plan on using my new Stewmac precision router attachment and circle cutter with a fine bit. Thanks in advance for any advice.

Bob

Now, because I'm not sure how you'd do it later. If you used your StewMac rosette cutter, use the same pilot hole and cut a circle not quite all the way through. The "hole" will drop out when you sand the top to its final thickness from the backside. Make sure the outside of this cut is the diameter you want your sound hole to be.

When I do my rosettes my top is still a rectangular piece of wood and a little thicker that the final top will be. I drill a small hole for the router base to pivot on in the top. The way I have it set up the drill bit shank becomes the pivot. I use a 3/4" piece of maple plywood with a hole drilled in in the same size as the pilot bit. On the underside I have glued an additional scrap of hardwood so the pilot bit is very well supported and straight up and down. I stick the top thru the pilot bit hole and put a couple small dabs of hot glue at the corners of the top attaching it temporarily to the plywood. This makes a nice work board. Route and install rosette then immediately cut out the rosette with the router. I Use an 1/8" Proxxion router and a multifaceted bit for this so there is never any tear out. If you are using a two flute bit or the like it might be best to not go all the way through as the previous poster suggests. Then I release the square soundboard with rosette installed and sound hole cut and drum sander flush the rosette then turn the top over and take to final thickness.

Yes , Cut soundhole before attaching to the sides

I cut my Sound hole after i've fitted and glue'd the rosette in place..I don't do any more drum sanding..I just scrape.

Thank you all for your most helpful replies. I have the soundboard set up on a board with a hole in it , as suggested and the rosette is done, all I need to do now is route the hole!

Cheers,

Bob