In general
I would like to make a circuit, where I have: a power supply (batteries), a dc motor, a button (when holding - close circuit, otherwise open) and maybe a power switch, just in case.
I would like to include a knob, that would control the max torque my motor can output (if the current would be higher, stop the motor).
I don't mind including some kind of controller, arduino or something, but I know next to nothing in this area (circuitry and electricity), so any guidance would be helpful.
I've been looking for possible motors, and found that steppers are not the good choice if I want the stall detection, maybe a dc motor with shunt resistor (yeah, I don't know what that is).
An example with dc motor (that I don't know how was made): youtube
Specifically
It's a DYI this thing: youtube (with minor adjustments, like instead of a counter, it's the stall detection + release button) with a system working like this: youtube (but instead of the metal "spring", it's the motor pushing them up.
To summarize: a box that has a motor automatically pushing tiny balls through a tube, and when no more balls can be pushed, it stops.
