I purchased four of the RB-Nex-40 continuous servos. I received them yesterday and installed three of them in my project. I am using three of these servos and an Arduino UNO to make a drawing machine. The servos do not seem to work properly. They spin at the programmed speed for a few seconds and then slow down to a very slow speed.
I have now tested all four motors individually, outside of my setup on another UNO board I have, with just one motor at a time, with just a power source and the microcontroller with a simple line of code to write a speed to the motor. I tried writing the speed to the motor in the void setup and the void loop. The behavior persists and none of the motors will maintain the written speed for more than a few seconds.
I also then powered the motors separately from the microcontroller using the maximum 7.4 volts from a high current source to ensure they are not starved and the behavior persists. I did this with a 12 volt wall source stepped down to 7.4 volts, and also with a fully charged high capacity Lipo. I used these power sources with the motors one at a time and am certain they could not be starved individually with this setup given the the power draw listed on the spec sheet.
I believe these servos are defective. But all four of them are doing the same thing so I am asking here first before returning them to see if I am obviously missing something.
Any advice on this issue?
I am using the following code on the Arduino. I comment out the line in the setup or the void loop individually… I am trying to format it as code in this post, but am not sure I’m entering it correctly in the post:
indent preformatted text by 4 spaces
#include <Servo.h>
byte servo1Pin = 2;
Servo servo1;
void setup() {
servo1.attach(servo1Pin);
// servo1.write(180);
}
void loop() {
servo1.write(0);
}
Editing to include this dropbox link to a video of the behavior. This video uses a fully charged Lipo 7.4V, but I get the same behavior from a wall supply at 7.4V and also from the USB supply. Here is the link: https://www.dropbox.com/s/qrw3jpfx88jnzio/IMG_4457.MOV?dl=0