OK, everyone all together now, "Ahhhhhhh! Now I understand!"
This is what I get from starting my journey with a Kleinbauer Seventh Sojurn. In his design, the reaction thrust is on the rod is taken care of by a skate bearing on the far (non-motor) end of the rod. His "nut" is just a piece of aluminum angle, tapped 1/4-20, and bolted to the bottom of the gantry equivalent, and his motor coupling is just a length of rubber tubing. OK for milling model airplane ribs, but not for what I'm now planning.
We needz a better pikshur, as my LOLcat would say. Ahren, I'm sorry to say that the nice CAD drawing on your Components List page has enough "slack" to lead me astray, but we've recovered just in time! I'll soon sketch one up, post it for your confirmation, and proceed with a clear mind. See, isn't it good to have a noob wander by and clarify assumptions?
