I keep bumping into the AB ultra 3000 servo drive as a follower for saws and such. The one I enjoyed most was a flying snap shear. A dogged, flywheel driven shear that cut high speed reduction rolled rebar. The enjoying part is when it hung up and sent orange hot spaghetti flying around the mill. The many videojet printers that I've worked with simply require an encoder input and a few parameter settings.I have had experience with a similar machines that probably works in the same principle, One is called a flying shear.
Where material such as fabric or sheet steel etc is fed continuously at high speed and needs to be cut to a specific length. The material is cut on the fly without the need for the material to stop.
Once the shear has operated it accelerates back and then resumes travel with the next sheet shear point is seen.
A carriage carrying the shear must be accelerated to meet the speed of the feed material before the cut occurs. Incremental encoders are used on the traveling parts to keep each in step.
The others are not so dramatic but similar in operation and are used to stamp the weight on pre-packaged foods such as cheeses, meats, fish etc, where the weight is not known ahead of time.
The conveyor motor in such a machine just requires a constant, uncontrolled RPM as the synchronizing is done with encoders on the crucial moving parts.