2g Servo Power Controlling

Robotics
1

Hi all;

As the title says, I am running 2g continuous servos (yes 2 gram servos) for my micro project, these will later be switched out for smaller 1.7g servos as they have a smaller footprint without getting into custom made servos. I am also currently running these off of an Arduino Nano and a 12V stepped down to 5V via a converter that I know is good (through a different project using Car voltage) this will also be switched out later for a 5V mini battery.

The issue that I am running into is that after a few moves (maybe 5) of the servos, they start to no longer fully move back to their final/initial point in space which is at 200° & 0° respectively. This is without any real load on them, one of them is moving a tiny metal wire which moves a pivot point, the second is pulling an elastic string against the opposing string of the same force value.

Both servos are sent a signal separately as to not have any mixed values, and they’re also receiving power directly from the voltage converter

So my I would like to know your guys thoughts on the matter as it has caused a road block in my project which I cannot get passed with my limited knowledge.

2

You may be approaching the need for a closed loop controller.

3

If they’re continuous-rotation servos then you won’t have any position feedback unless you manually added an encoder.

Continuous-rotation servos are quite dumb (especially the micro ones, you can’t squeeze very much processing power into that small space), and all they do is convert the servo signal into PWM signals into an H-bridge which drives a DC motor. And if the motor is loaded, it won’t run as fast as it normally would, etc etc.

tl;dr if you care about precision position, use an encoder.