How to properly position the Assembly in the drawing?

There are machines that handle the rotation body with a vertical position of the workpiece. Place on the drawing so that the placement optimally fills the sheet. But horizontally looks better.

The axis of rotation of the part is horizontal. But if the whole Assembly consists of bodies of rotation, then why not arrange the Assembly horizontally.

I often arrange assemblies the way they will work in life. Example: a product of cylindrical shape, small dimensions, when processing the axis of the parts will definitely be located horizontally (in the drawings of the parts, the axes are horizontal). But the product will work strictly vertically.

Dispose as you please. In extreme cases, the drawing is rotated.

There are no strict requirements, but the part is desirable to have as it will be on the machine (for example, lathe), and the Assembly is desirable in the working position. With all this, in my practice, there were cases when the part was located on the drawing as I (the designer) was convenient, well, for example, a small detail is not always placed on the A1 format. At the same time, we must not forget the main requirement - the convenience of reading the drawing.

The design is always drawn as it then works. Here it seems to be the same type of design-dies for stamping on crank or hydraulic presses and molds for injection molding. And there and there halves, between which is obtained detail. But stamps are put on the press and halves are obtained upper/lower. And the molds are placed horizontally, and the halves are obtained right and left or, as it is customary to designate by the principle of work - movable and stationary. Accordingly, the guide columns/bushings from the Assembly in the detailing fall differently. With stamps-the axis is vertical, with molds-the axis is horizontal. If you start to change the location, with adjustments, the designer can skip the jambs when measuring. Bushings-columns for example, the complexity of the parts is very different.

That the machine operator saw how exactly the workpiece is on the machine, instead of taking as a basis already completed design drawing, not the most rational occupation. You can imagine how many sketches had to be drawn, if the whole process took hundreds of operations.