The pasta machine is basically a small mangle that rolls out the prepared pasta into sheets. (It does not, contrary to popular belief, make the pasta dough - this is done in a mixer, food processor or, the best way of all, by hand.) Then, if you have the attachments, mounted on the back as in the picture, you feed the sheets through the cutter which, depending upon the type, produces various grades (widths & diameters) of tagliatelle or spaghetti.
With our own chickens giving us an almost unlimited supply of eggs, we use our Imperia pasta machine quite regularly. Where we have it mounted, it takes two people to successfully make pasta: one person winds the handle while the other, with a chopstick, gathers up the emerging pasta so it does not all pile up on the work surface.
Raymond Blanc showed me how to use the machine properly!
I've always run sheets of pasta through the machine, one sheet at a time, re-inserting the sheet on thinner and thinner settings. This method really requires 2 people, one to wind and the other to gather up the extruded sheet. Invariably the sheet becomes torn or spoiled and has screwed up and re-started from scratch.
I recently saw Raymond Blanc use this pasta machine properly. He ran a sheet halfway through the machine on a thick setting and then simply joined the extruded end of the sheet of pasta to the start of the sheet about to enter the rollers, creating one continuous loop of pasta sheet. From this point he just turned the handle constantly and adjusted to a thinner setting every time the 'loop' had been through the machine a few times. Absolute genius!!
If I were to buy a pasta machine again, I would not bother with the spaghetti cutter, or even the tagliatelle attachment. The pasta is just as good if you roll out the sheets, lay them on a floured work surface and slash them into rustic looking strips with a knife. But then I never was strong on presentation!
It is also possible to use a wheel cutter for pasta (children love it) and make tagliatelle 1 cm wide (a.k.a. 'pappardelle') with a zigzag pattern on their border. It taste the same, but it's a small improvement on the presentation.