I found this picture somewhere on these message boards (can't remember were): http://www.geocities.com/maglight2000us/index.html and was going to implement this same design for my machine. But I'm not entirely sure how it works. When the acme rod is rotating, how exactly does the roller bearing react from each side? I'm assuming that the inside of the roller bear moves while the outside is stationary. If that's the case, then is the roller bearing pressed fit inside the wood counter bore? Can someone explain how this works?