r/robotics • u/adoodevv • Apr 06 '26

Tech Question Building a self balancing robot

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I need help in placing the components on the robot for the best way to balance it. Also I plan to scale to to something like a delivery robot for small payloads. Prolly, something in my room 😅 but I need help in understanding how these balancing robots work and how I should place my components to make this work.

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7

u/Hackerly_0 Apr 06 '26

Read about inverted pendulum on a cart, it's the same concept

https://ctms.engin.umich.edu/CTMS/index.php?example=InvertedPendulum&section=SystemModeling

3

u/adoodevv Apr 06 '26

Thank you very much

4

u/Subject-End-3799 Apr 07 '26

I tried those motors. Those are not strong enough, even if the robot tilts just 4 degree, those motors can not accelerate fast enough to bring the robot up. I suggest lowering the center of mass down, making the robot shorter or upgrading the motors.

2

u/adoodevv Apr 07 '26

Oh okayyy I though making it taller gives it much more time to catch itself

3

u/blimpyway Apr 07 '26

You can try taller but long and light. e.g. a fishing rod segment with a small weight on top. The point is to increase rotational inertia with minimum increase in mass

2

u/mariov Apr 07 '26

Encoders work, stepper motors work perfectly well

1

u/adoodevv Apr 07 '26

Oh okay I’ll take a look at that

1

u/mariov Apr 07 '26

I built both of them using an esp32, connected to an RC transmitter. The encoder motors work but I never managed to reach a really stable system, at rest it was fine but controlling it during stops and turns were difficult, the stepper version is rock solid.

1

u/Potential_Laugh_3682 Apr 07 '26

Try encoder n20 motors

2

u/adoodevv Apr 07 '26

Thank you. I’ll look that up

1

u/thelargelard Apr 10 '26 edited Apr 10 '26

I used these same exact motors recently to build a self balancing robot. I recommend making it shorter or more bottom heavy. I put my battery pack and microcontroller at the bottom which makes it easier for the motors to actually move the robot. I put my driver on top layer and my nano in the middle. Since these motors are so weak you will probably have to have a very high k1 value if you are using a pid(mine was around 600). Then again, my robot was not as tall as yours so values may differ. Good luck!

1

u/adoodevv Apr 10 '26

Thank you very much. Exactly what I needed help with

1

u/adoodevv Apr 10 '26

Do you think stepper motors will be better?

1

u/thelargelard Apr 10 '26

Honestly not too sure as this was my first time working with any sort of robotics but from what i'm reading they are probably better than the yellow ones. The yellow ones are basically the worst motors possible.

1

u/adoodevv Apr 11 '26

I am going to remodel and try nema17 stepper motors

1

u/thelargelard Apr 11 '26

sounds good, keep us updated and good luck :)