I am working on a current (lengthy) sawmill project that is detailed here:
I want to add an electronic device/motor/actuator that will allow me to adjust the throttle on a gasoline v twin engine. I am trying to figure out what device will be easiest/best/cheapest to implement . I plan to control the device with the current arduino I am using in the above project. I would like it to be powered with the same 12v dc battery source as the engine and current arduino. I will post a picture of the "lever" that needs to be turned to adjust the throttle speed. I would like to keep the device in the 10-20 $ range I was thinking a servo motor would work well, but I can't find many that work on 12vdc power.
5V is easily obtained from 12V with a regulator or converter. Even the Arduino itself usually has one on board. But an external voltage regulator or converter would isolate the servo power better from the Arduino.
Actually, a Google of "Arduino servo" will get you a lot of information (but also disinformation in the form of servos powered directly from the Arduino 5V). Also Google, "5V step down converter".
The reason is, I suspect a the carburetor may be a little too sensitive for and RC actuator. And an RC actuator can go from idle to full throttle really fast. If there is a broken wire of voltage spike somewhere the actuator could go full open or closed in < second.
The Stepper with threaded shaft will likely be able to generate more force and will move more slowly requiring more than an error caused by noise being loaded into a register.
Powering an Arduino from a 12 volt system in a vehicle will likely blow the controller as, during charging, the voltage is some 13.4 volt. When the charge regulator fails the voltage raises a lot. 15, 20,..... I don't know.
If I used a stepper with threaded shaft like you recommended, what is the easiest way to mount it to the lever going to be? I am going to have to figure out how to mount what ever I use. I really haven't come up with a good way to do it.