It all began when Ray found a crane model in one of Yoshihito Isogawa’s book “The LEGO Technic Idea Book – Simple Machines”. He really liked this idea and decided to create one using LEGO WEDO 2.0 set.
It is a simple model but contains the fundamental parts of a crane, the jib and reel. Let’s build it now!
Build the Chassis
The design of chassis is actually very flexible. It provides a basis to put the motor, smart hub and jib. Our model has a long and low chassis (almost touch the ground). The smart hub and motor will be put on it directly, rather than stacked together. Those measures ensure stability of the vehicle.
Build the Jib
The important part of the crane is the jib. In this model, the tilted jib (white beam) is strengthened by another beam (green) to keep them fixed on the vehicle. The lifting up and unloading of the goods are done by the pulley installed at the top of the beam.
When the beams are tilted, they need more space at the bottom to avoid interference with other parts. The current design could make the beam rotate freely in the pin holes of the bricks.
Build the Reel and Motor
The next step is to build the reel and connect motor with the gear and pulley. Put reel in the middle of two Technic bricks and connects those parts with an axis. The axis can rotate freely within the pin holes of the Technic bricks, and bring reel spin together with it because the reel has axis hole.
There is only one input power from the motor in the model, but the output could be separated into more than one sources. One output will drive the wheels through gears, and the other output will drive reel through belt drive.
We Have Learned Those Structures Before
Now we create a new model but some design ideas could be found in the guided projects. That is why in our courses, we always emphasize the teaching of guided projects and explaining to the students why those structures are built in this way, rather that in that way. Let me show you two mechanical structures already introduced in the guided projects.
Guided Project – Steering Model
In this guided project, it uses gears to transmit the input of motor into the rotation of wheels. The crane model uses the same method, except that the size of gears is different since its chassis height is a bit different from that of the Steer model.
Guided Project – Helicopter Model
Both the helicopter model and crane model use the reel structure. It puts the reel in the middle and lets the axis pass through it. It then uses belt drive to rotate the axis and reel.
Finally, the Model…
Let it Move By Programming
The programming part is very straight forward. If I click the “Play” button on the top, the crane will move forward and lift objects. It will show the text “forward and lift” on a small screen and play a sound. If I click the “Play” button at the bottom, it will move back and then put down things. I can choose which code segment to run and how many times to run.
That is all about the process of creating a new model. Enjoy the fun of design and coding!
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