We investigated the drivable range of the PR3 SF stepper motor.

We checked visually and drove the motor to the upper and lower limits to find the limit.

The starting point was zero.
The stepper motor was moving downward in the positive direction (left rotation) and the KeyStone was moving downward in the positive direction.
This was the same as PR2.
All of the PR series seem to have the same direction of KeyStone downward movement in the positive direction of the motor.

I drove it through 50000, 550000, 1050000, 1250000, and 1500000.
At around 1413831, I stopped the motor because it made a strange noise that I didn't hear.
In the minus direction, I drove the motor to -50000, -100000, -150000, -200000, and -250000.
The remaining gaps were only a few millimeters, so we did not investigate further.

Results :
 We set the driveable range of the PR3 SF GAS stepper motor to the following values.
 Upper limit: 1400000[count](27.3mm)
 Lower limit: -250000[count](4.88mm)