I figure this might be helpful to some of the builders out there. I built a similar one today. I built it mostly just so I could thickness small parts easy (headstocks, backplates, truss rod covers, etc.) since it takes a while to do it with my planer when you need to get rid of a lot. I added a pin anyway (shank of a 1/2" shank router bit) and I tried it out and it works great and is perfectly accurate so I'll be using it for a lot of the cavities on my guitars probably since it's easier and faster.