Servos External Power Supply Error

Other Hardware Motors, Mechanics, Power and CNC
1

Hi, I'm new to this community and also a fresh arudino user.

My first project is a 3D printed robotarm and I ran into a problem: The arm consists of 6 Servos (3x MG996r and 3x SG90), I know I have to power them with external power so I connected all the singal cables from the servo to the different Digital Pins of the arduino. To provide enough power for ther servos I use an ESC from a RC plane, which says 3A@5V, connected to a 3S 11,1V LiPo. Now I put the +5V cable and the ground cable from the ESC to that vertical pin line on a breadboard, same with all the servo power cables. At the end I put a cable from the Arduino GND to the GND line of the breadboard. Now, if I plug the Arduino USB to my PC (I power it that way) the servos sometimes work, put espacially those which need a bit more power for some movements often just do noises like "grrrt grrrrt" and if I assist the arm a bit it does the movement.
I really dont know whats wrong, I used serveral different power supply methods (direct breadboard power suppy with that tool and a 12V/1A calbe, I even tried 4 AA Batteries, but nothing seems to work...

Someone maybe got a clue whats wrong?

Thanks already for your help!

2

Depending on the ESC it may not deliver a full 3A. And anyway 3A is not a lot for MG996s which have a stall current of 1.4A each.

But I suspect the main problem is trying to run all that current through a breadboard. Most can only handle around 500mA and no more than 200mA would be safer.

Try wiring the servos direct NOT through the breadboard, particularly the MG996rs.

Steve

3

slipstick:
Most can only handle around 500mA and no more than 200mA would be safer.

Damn, I didnt know that, thanks very much. I will try it and let you know, just in case some newby like me has the same question anytime.

Small question: Can I solder them to a PCB or is it also unable to carry those high currents like the breadboard?

4

Soldered to PCB or perfboard is fine. I often use 3-pin servo-type plugs soldered to Veroboard for groups of servos.

It's just the weedy spring terminals in breadboards that won't take the current. If you ever take one apart you'll see what I mean.

Steve