The phrase "mechanical machine" is correct and usable in written English.
You can use this phrase to refer to a machine that has been designed to perform a task using mechanical processes, such as a car engine or a printing press. For example, you could write, "The mechanical machine was essential in mass production of the finished product."
I quite quickly came up with the idea of some sort of mechanical machine.
He also solved the problem of the time-consuming work of dividing the prize money among the winners in proportion to the size of their wagers by inventing a mechanical machine, the compteur totalisateur, to perform the necessary calculations.
When a voter using the mechanical machine presses down a lever beside a printed choice, the return of the lever to its original position causes a tenth of a turn on a tens counter, which is connected to a hundreds counter.
And recently, a mechanical machine dated to 2,100 years ago and found in an ancient Greek shipwreck was determined to be a sophisticated celestial computer the like of which was not to be produced again for at least a thousand years.
Nature is depicted as a mechanical machine and should be studied by the natural sciences.
The mechanical machine is being converted into a computer.
As an important supplementary to machining experiments, molecular dynamics (MD) simulation has been demonstrated to be a powerful tool for elucidating fundamental mechanical machining mechanisms of different kinds of materials.
Mr. Raymer, who used to make mechanical, machine-driven pieces, had been installing Sheetrock for years before he realized he could use the stuff for his own work.
Its enduring images were of mechanical machines counting pile after pile of disputed ballot papers and pregnant chads.
The holy grail for nanotechnologists are sub-microscopic chemical or mechanical machines called assemblers that can reproduce and repair themselves.
At the train station, mechanical machines used to buy railroad tickets were unreachable for people in wheelchairs.
