Here is why the router was sounding funny even when it was running well. The bit is a Melin AMB-808-#AITIN The overall length is 4 inches and has a 1.5 inch cutting depth. When I put these bits in the router (Dewalt 611) I push them all the way up and back down about a 1/4". If you only seat them to the collet depth when you start the router they are very sensitive to runout. So the combination of a long length and 1.5" cutting depth it created a lot of vibration. The project just wiggled its way loose.
Here is the picture of the first attempt when the project came partially loose.
I thought about putting a butterfly patch in the back but in the end it was just easier to cut a new one.
This is a Jet 1221 VS Steady Rest for one of my woodworking club members. He turns and sells his products at craft shows. I also made him a Wedgie Sled for cutting segmented bowls. I posted the instructions for making the Wedgie Wedges in the “How to” section if you are interested.
As an after thought the material is maple plywood. Would you select “Hardwood” or “Softwood”. I selected softwood because it is plywood. For hardwood plywood what do you select for your tool database?
I have compared the same tool with softwood vs hardwood and the softwood tool runs about 15% faster over the hardwood tool.