It's been a few days since posting but things are moving along well. I made the wooden prototype. and found a few problems that needed addressing. After building the knife holding block I found that I needed everything to be adjustable. I needed to be able to tweak the knife this way and that. So I split the arm and added two blocks face to face to hold the arm, but the one block will have over sized holes (by 1/16") that will allow for tweaks.
The next problem was with the knife, I can put in slots to mount the knife forward and back, but I needed to add a stop to adjust the height of the knife. So in the block I added an allen head bolt that will sit between the legs and hold the knife up.
Here is a sketchup pic of the modified design.
I'll try to get a video or a few pics of the wooden proto up this week, as well as a few in process pics.