First time I tried had the same problem, so I just cut it even larger and used maple (what I had on hand) and lined the area and re-routed it. Came out fine and works great. I think if I ever do another one, and I will, I may just start out with the liner. Can't find any good pics so I will go down and take one now, back.
Wisdom: Where experience and knowledge combine and become one.
"We are all one decision away from Stupid!!"
"How often we sacrifice the permanent plans of God on the altar of immediate solutions"
I have a very good memory, just short is all.