How to create a vertical movement

[jwalter007]

I have what most would probably say is a simple engineering problem.
Im building a device which requires a U-Channel aluminum part to be vertically adjusted from a fixed part. I can't figure out which part should be threaded and where the nuts should go.
I have attached an image to show what I am attempting.
Thanks for the help

[jboggs]

For this to work as you describe the connection on the lower channel cannot be threaded. The rod will have to rotate freely in the hole in the channel and still pull the channel up and down with it as it translates, just like the screw bearing in a linear actuator setup.

[jwalter007]

Thanks for the reply.
What might I do to make the bottom connection? I tried 2 nuts on the very bottom but it still managed to spin & loosen. I did not try a lock nut...maybe that would work?

[jboggs]

You need to attach a nut to the screw so that it cannot turn on the screw. You could use a lock nut or a jam nut. You could weld the nut to the screw. That way as the screw travels up and down as it rotates, it will carry the channel with it.