Powering multiple servo motors.

Hi all! I am currently building a robotic arm built from 5 servo motors:

2 Hitec HS-HS-422 (Standard size)
1 Hitec HS-805BB (Giant scale)
2 SG90 micro servos

My breadboard is powered by an MB102 5V power supply.

My background is computer science, and when I run my code (simulating the arm movement) the servos move without a problem and don’t glitch.

The servos are also strong enough to lift each of the arm’s components (tested).

When I connect the arm components to the servos (Base servo to rotate the arm, 2 joints, 2 servos for gripper - one for rotation other for gripping), it seems like the servos are not getting enough power to move the arm accordingly. More specifically, the arm moves seamlessly at first, but once one of the servos is holding a position, and another needs to perform an action, it seems like it is not getting enough power to move the arm components and just glitches out, making vibration noises.

I assume this is because the servos draw more current when performing an action, and when they have something to lift, the voltage supplied to the system is not sufficient, especially when a different servo is holding one of the arm components at a certain angle.

My background is not EE so any advice as to better power the board / provide a more steady supply of power to the servos would be very helpful!!

Thanks a lot :slight_smile:

Insufficient power is the cause of 90+% of all servo problems, and almost certainly your problem too.

Breadboards carry signal level power quite nicely.
Want to light up a dozen or so LEDs? Breadboards are your friend.

But powering motors like those used in a servo and you are at the limit of what they can carry.
Put on multiple servos, or very current hungry servos and you can no longer distribute the power through a breadboard.

Much better to have an adequate power source and distribution method.

I am afraid that your power supply is not up to the task.
3. Output voltage: 3.3V/5V; Maximum output current: 700 mA.
Your big servo draws more than that with NO LOAD!!! :slight_smile:

A better power supply and better power distribution are going to help you.

BooleanLogic21:
I assume this is because the servos draw more current when performing an action, and when they have something to lift, the voltage supplied to the system is not sufficient, especially when a different servo is holding one of the arm components at a certain angle.

The voltage drops because the supply is completely overloaded - this shouldn't be happening, it indicates
the power supply cannot supply enough current.

My background is not EE so any advice as to better power the board / provide a more steady supply of power to the servos would be very helpful!!

Thanks a lot :slight_smile:

Yes, provide a supply capable of at least 25% more current than the maximum that will ever be drawn,
no more issues with power. Even small servos can draw about 1A peak. Make sure the wiring is good for
the currents involved.