The Moment Makers

In LEGO Inspiration today, we will show you what we found interesting in LEGO Legends of Chima set number 70008 Gorzan’s Gorilla Striker.

This is a discontinued LEGO set from The LEGO Legends of Chima series. In Chima, Gorzan and other members of the gorilla tribe use these mechs to swing from vines and walk/run to cover more distance than they could with just their minifigure bodies. The mech’s arms move to help grab the vines, defend themselves, pick up people and things, and make hand gestures, like when they need to give directions to the rhinos.

This set offers a lot of movement with LEGO joints for fingers,  hips, and knees, as well as several missile sites. However, for the purpose of helping EV3 builders and FLL teams, we are going to focus on the gearing that allows the arms to move up and down by turning a knob in the mech’s back.

Redirecting Movement

In this model when you turn a piece in the back, the two arms move up or down together (depending on which way you turn the piece in back). How is this possible?

Arms reaching forward…

Arms up…

We looked into the model and we found that the piece that we turned was on an axle, and on that axle was a gear. Intertwined to that gear was yet another gear, but this gear was rotated so that its axle was turned to point toward the arms. These are called perpendicular gears. The arms also have axle holes so that the they can connect to this axle to allow the movement.

The gears redirect the movement to face another direction, so you would not have to turn the arms separately by hand. Even if the arms were connected together with an axle you would still have to move the arms from the outside of the model, if it weren’t for these perpendicular gears.

In building with Technic or with your EV3, remember perpendicular gears when you need to change the direction of movement! For example, if your robot has motors that face forward but you want the motor to control a lever motion on the side of your robot, you can use the idea of perpendicular gears with single or double beveled gears (as shown in the Gorilla Striker model) or the knobbed Technic angular wheel (a 4-toothed “gear”) to change the direction of the motion.

This is an example of using the knobbed Technic angular wheels to create a perpendicular alignment for the gears. We colored one yellow and one black to help you see each one.

Thank you for reading this article! Hope you learned a lot from it!