Building a Hydraulic Lego Excavator

Building and testing a remote controlled hydraulic excavator with Lego. The excavator includes 6 motors controlled by a BuWizz 3.0 (a remote control and battery unit).

An electrical slip ring is used to connect the 2 track motors through the rotating turntable with the battery box. 2x CADA micro Motors are used to power the tracks. They are small, providing high torque, and having low RPM.

The turntable is moved by a Lego small angular motor for space reasons and because of the low RPM, which provides better control of the superstructure.

3x Lego Technic Powered Up Large motors drive one pump each. To make the small Peristaltic pumps, a Lego part had to be modified by drilling holes. The pump works with Regular Lego pneumatic hoses. It builds up a lot of pressure/vacuum, enough to operate hydraulic systems, and it works in both directions.

The Hydraulic cylinders are actually Lego pneumatic cylinders. They are not intended to be used with water as the metal parts could corrode. To avoid this, I used a mixture of windscreen wiper fluid and water. The system requires some air, as the 2 cylinder chambers are different in size and therefore require a different amount of water. Each pump powers its own independent circuit and, respectively, 1 excavator arm joint.

The PS4 Gamepad is connected to the BuWizz 3.0 Bluetooth Unit with an App called Brickcontroller2. The app allows the user to assign buttons of the gamepad to individual motors. The analog sticks of the gamepad resemble the 2 joysticks of a real excavator, adding more realism.

The design and proportions of my Lego digger resemble the CAT 390L, which is why it is in Lego minifigure scale.

The hydraulic system works without fluid by pumping air. However, the movement is not accurate and lacks power.

I made 3 custom parts that are 3D printed: a slip ring mount, a pump housing insert, and an excavator bucket. However, the excavator would function without these parts. The slip ring does not need to be mounted; the pump insert could be attached with sticky tape, and the Lego Bucket would still work despite being big. However, I greatly prefer using a custom shovel.

Chapters:

00:00 Tracks
00:16 Turntable
01:10 Pump
02:52 Arm
03:45 Controls
04:26 Bucket
05:21 Test


3D Design Software: https://link.shapr3d.com/cad-5589a6
3D Printer: https://store.creality.com/products/e...

BuWizz 3.0: https://buwizz.com/shop/buwizz-3-0-pr...
CADA Micro Motor: https://shorturl.at/bnpvN
Small Angular Motor: https://shorturl.at/BCKMP
Lego Large Motor: https://amzn.to/44fjuoz
BrickController2 (App to use Gamepad with Lego): https://bit.ly/3JypnV0

Slip Ring: https://amzn.to/3QIlBy4
Pipe: https://amzn.to/3QGl8fG



Please note: I get a commission if you buy via Amazon or BuWizz link above. Thanks for your support.

Where I get my Lego parts from: https://www.bricklink.com/v2/main.page

Music: Riffs For Days - TrackTribe
Ode to Joy - Cooper Cannell

​#bricktechnology
#legotechnic​
#lego
#asmr
#engineering
#excavator
#construction