Channel Mount Gearbox Kit - Standard Rotation (7:1 Ratio) not working as expected

Kits
1

Hi,

I recently purchased a:

I performed all the task described in the modification instructions (correctly) and finally I applied a simple Arduino code through a Arduino BlackBoard (pin 9, 5V and GND):

Edited by moderator to add code tags

#include <Servo.h>
Servo myservo;  // create servo object to control a servo
int pos = 0;    // variable to store the servo position
void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}
void loop() {
pos = 15;
myservo.write(pos);
delay(1500);
}

But the result is this one:

https://www.youtube.com/watch?v=oAsqUBV6HKY

I know it would be hard, but do you have any clue of what can be not working well?

Thanks in advanced…

2

Hi AsierPz.

Exactly what modifications did you do to the servo? The behavior I’m seeing in your video looks like the servo is running into the end stops built into the servo and backing off. Can you provide a link to the modification instructions you’re using and post a few photos showing the changes you’ve made to the servo?

Also, can you rotate the servo more than 180 degrees or does it only move about halfway around?

3

I attach you the instructions I followed, but as is not is the same servo I had to improvise a little bit.

I also attach you photos of my work (change of the potenciometer and removal of servo’s stop pin)

Answering your question both servo and gearbox rotate without any limit.

https://ibb.co/3cbypsV

https://ibb.co/410wfqT

https://ibb.co/JKfCd85

https://ibb.co/Pcnfk22

https://ibb.co/sFrkyrB

https://ibb.co/Swgqxjd

4

The only thing I can think of is that it’s possible you either damaged the servo control board while you were modifying it, or you may have the potentiometer wires in the wrong order. Since you used a different servo that what was in the instructions, it’s hard to say what the issue could be.

Have you tired physically removing the servo from the channel mount so that it can free wheel and see what happens if you instruct it to go to 90 degrees? Doing that and manually rotating the potentiometer should cause the servo to run either forward or backward at varying speeds depending on where you set the pot too.

If the servo isn’t doing that, you might need to try a different servo.

5

Thanks for your answer Chris.

  1. I removed the channel mount pot and I’ve connected the wires to the servo’s own potentiometer. It works properly.

  2. I’ve reconnected the wires to the channel mount pot. Now at least it moves smoothly, so I suppose that maybe the welding was not ok. Anyway, it still rotates without any limit. That makes me think that as you said the wires from the board to the new pot could be in the wrong order.

To be honest it is hard to know which the correct order is, because I have no information from the servo’s control board, nor from the channel mount pot.

Anyway, after making some measurements with a multitester, I saw that the channel mount pot and the servo’s one work just the same way, so I joined them in the same order as there were (https://ibb.co/3cbypsV).