I am trying to constrain a piece that moves on a lead screw and is supported by two rods(image below). The piece should move linearly along the rods as the screw rotates. I am having an issue constraining the housing to the rods and screw as a mechanism. The best option seems to be the cylinder option, but I can only constrain it to one of the rods or screw and when I drag it, it rotates. Is there a better way to do this?
It's probably simplest to use a single slider connection. Just use the axis of one of the rods and then use a plane (from the same rod) to prevent rotation.
You could use two cylinder connections for the housing and shafts and a slot connection for the housing and screw. For the slot connection the thread rod would have a helical curve and the housing would have a point that moves along the helical curve.
It is best to just go nuts on the different constraints to learn what each does.
There is nothing instinctual about these constraints including their implied names.
They are a very basic set with the means to lock down the parameters you require.
Hint: you can create more than 1 constraint set for a single object.
Hint2: you cannot always have direct connections as you would think in the real world.
For the lead-screw, I would do a generic gear connection between the linear traveling carriage and whatever you tie to the rotational function.