Metal hand Saw machine

Using a carbattery, a lightswitch, a car-window-wiper-motor, and a 3D Printer, i've comprised a simple automatisation for the metal handsaw.
For even, straight cuts of INOX 316 & 304 linear rods,
electric tools were too violent, and resulted in ugly sawcuts, burr and slivers.
This is my 60$ weekend solution to a +300$ slowcutting metalsaw.
I figured that, if i added an arm to the wiper motor, i could make a circular motion,into a repetitive, linear one.
The next step was the math.
If i ad