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Anyone had the router bit slip while cutting rosette channel leading to a rosette that's too deep or even an unusually large soundhole (due to through cuts)? What have you done to fix them?

I just had the router bit slip on me causing the rosette channel to be too deep... it almost went through on one part, and went all the way through in another part before I realized what was happening. So I ended up using another purfling and laid it in really deep, and the other part I simply inlaid more purfling on the wrong side to hopefully close it up. I will then cover it with some scrap spruce to make it look good (it was a commission)

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If it went all the way through then it's pretty much trashed. You will have to rout out the rosette making a new sound hole. Then you could make a disk out of spruce (or what ever top material you are using) that is about an inch larger then the 'new' sound hole. Then make another disk the exact side of the new sound hole and laminate them together on center. Now you have a traditional doughnut sound hole brace and a disk as a filler. Then make a new rosette to fit and re-rout. I did this when I made a sound hole too large by accident and it worked well. But in your case you are going to have to rout out the whole of your rosette channel having a huge sound hole that needs to be filled. But it might work. Make sure that the grain orientation of the filler disk is the same as the top.

You could also use some other wood for the filler disk if you want to have an interesting sound hole edge design.

Or just start all over again because by the time you do all this work you probably could have joined a new top, plus you may end up having to use top wood to make the disks.

Don't know if this applies to you but this can happen if the bit is place fully into the collet. The bit expands and has to go somewhere. It needs a little room (~1/8") to expand.

If this doesn't apply to you the collet or the bit may need to be replaced. Collets have a service life and wear out whether it was made for a big tool company or Harbor Freight. Router bit shafts can get damaged/deformed when overtightening.

I've heard of one guy who did that and did a full spruce backing around the sound hole like you see on some classicals. Wasn't me of course.

Me too...



Me.

As DannyV mentioned there is an easy fix.

Flip your top over and add a patch of spruce around the soundhole like on a classical build. It will run from your X brace to your brace just above the soundhole. Kinda looks like a little baseball diamond with a square top.

Flip back over and fix up your rosette depth.

When you cut out your sound hole you will notice that the remaining patch will act as your sound hole braces. I do this on my builds anyway as I bind my soundholes and the extra thickness gives me a good edge surface to glue to. Looks pretty snazzy too!

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I've done that on a uke top....cut right through the top Sound Hole Patch to the rescue!!!
I glued the sound hole patch to the underside of the top. Drilled a center hole for my circle cutting jig, then glued the cut out part of the top to the sound hole patch using the center holes to align it. I did have to re-route the rosette channel slightly larger because the centering wasn't perfect. Just one more strip of purfling solved that