Servo SG90 With Unmodified Lego

Using cheap servo in Lego-arduino builds.

Newer version, with less parts: https://www.instructables.com/id/Servo-SG90-With-Unmodified-Lego-V2

There are several guide how use SG90 servo with lego. Most of them require customization of lego/servo or 3d printed case.
This example is using original LEGO pieces. I tried to use parts that easy and cheap to get. Some variations are possible if you don't have exact parts.

https://www.instructables.com/id/Servo-motor-Adapt...

https://www.youtube.com/watch?v=3m0FgZjfbdM

Part list (with lego ids):

SG90 servo 2 screws

2 screws

Brick, Arch 1 x 4 (3659) x2

Plate 1 x 4 (3710)

Plate 1 x 6 (3666) x7

Technic, Axle 3 (4519)

Technic, Axle 4 (3705)

Technic, Axle Connector 2L (6538)

Technic, Brick 1 x 4 with Holes (3701) x 5

Technic, Brick 1 x 6 with Holes (3894) x 15

Technic, Bush 1/2 Toothed (4265a/4265b) x2

Technic, Bush 1/2 Smooth (4265c)

Technic, Bush (3713)

Technic, Gear 12 Tooth Bevel (6589)

Technic, Gear 16 Tooth (Old Style with Round Holes) (4019)

Technic, Pin (2780/4459/3673) x 12

Use 2 screws to attach gear to white part that come with servo. Cut corners with e.g. knife.

Put servo under black arches. Fix it with 1x6 brick (red).

Prepare other axle with gear.

Fix servo axle with 2 bricks and plate. This will prevent axle from leaning to sides, or detaching from servo.

This will add extra durability.

Examples if you want to put servo on side.

Or if you want to attach something to servo closer to the axle.

Video show how it could be used to make simple robot with arduino.

It could answer yes/no to your questions (controlled by 2 buttons).