Stupid Question

[Jerome Hanby]

If I'm expecting to turn a piece of threaded rod against a short section cut off of the same rod that is held stationary (so it can't spin) and against the primary rod so that when the primary spins it will move the short piece up or down the rod, is it possible to have that short piece pointing the wrong direction?

[Mark Ashmeade]

Don't understand this bit:


turn a piece of threaded rod against a short section

It would be normal to have a tapped block on the primary so that when the shaft spins, the block moves up and down it, provided there is a mechanism to prevent the block from spinning with the primary.

[Harvey Melvin Richards]

If I'm expecting to turn a piece of threaded rod against a short section cut off of the same rod that is held stationary (so it can't spin) and against the primary rod so that when the primary spins it will move the short piece up or down the rod, is it possible to have that short piece pointing the wrong direction?

No, it's not possible (according to my take on your question). A threaded rod will mesh with any off cuts of said rod, regardless of how the end is oriented. If you are trying to make a jacking mechanism, you will have better luck if you add a female threaded part.

[Jerome Hanby]

I thought about hack sawing a nut in half and using it in place of the rod, but the project plan uses the threaded rod in both places. If it doesn't work better actually clamped across a board, I think I'm just going to forget the quick sliding adjustment feature and replace that little piece of threaded rod with a captured nut and just crank it as required to get the necessary opening.