@PaulKinlaw - You have the 1K, I had the same problem. I figured out through process of elimination (of parts) that you use the 2 long bolts and the 2 post-insertion nuts that were separate from the other parts to create a point against which the 2 homing switches hit. The post-insertion nuts can be added after it is together, thus the name. Just push them in carefully (insert with the joint of the springs and the nut going in first) push it so that it lays flat. Once in, if needed, use a bolt to make it lay flat against the rail in the groove. Then you can slide them to the spot needed and insert a long bolt in until it bottoms out so the screw/bolt won’t slide anymore. It’s nice because you can adjust the limit/home if needed, but I didn’t see any instructions either. I will post pics when I get home if needed.