Aligning objects on a centre line

I have many objects to align accurately about their centres, but I cannot find a tool to do this. Aligning faces/edges is straightforward but centres? Here’s an example with 4 objects I want to align on the horizontal rod (just for illustration).

With the rectangular blocks, the align tool you can pick the centre of the face and align with the centre of the rod, however it also moves along the x axis. To get back to the original x position, I added a construction plane to the perpendicular face and then after aligning the centres, aligned the face to the construction plane. Rather a long winded way, but got there.
However, I couldn’t manage the cylinders. You can select the centre of the cylinder and align with the rod as in this screenshot:


Although the cylinder can be rotated to original orientation, it will not align to a construction plane as for the rectangle.
The question is, where’s the ‘align-all-the-selected-objects-along-this-particular-axis’ tool? Dropping nice flat sided objects on a plane is OK, but curved? And then it’s only 1 at a time.
It’s all unnecessary/tiresome work … unless you know of a simple solution? :slight_smile:

Would this work? By using the measurement tool?


Yes, you can measure and move back to the original place (in that dimension) but with many objects this is not a particularly exciting prospect!