Multi-axles, many-directional LEGO Mindstorms mechanism. Worm Gears. Part 2 Pro Preview

We are describing the Warm gear in this video. This worm gear does most of the magic of controlling how the different gear wheels move on the different axles. 

  • #189
  • 10 Jan 2016
  • 3:29

A worm gear along with a fixed gears can move a construction. This is an important concept that you should learn how to use. Such movement allows different robot constructions to lift or move heavy objects with a little input power from the LEGO Mindstorms EV3 motors. 

This video is part of the course at:

Multi-axles, many-directional LEGO Mindstorms mechanism for transferring power (almost a gear box).


Previously we started with this mechanism that was rotating a different axle depending on how we control the motors and it worked like this. We had an axle rotating, this one here, and now we can move

and start rotating the other axles. We stopped at the way we control the movement of the different gears and this is the subject of this video.

The magic is actually in this worm gear on the inside. You can see these are 1, 2, 3 worm gear parts and there is a small 8th gear inside. And it's the same gear wheel as this one here, so it's a small gear wheel. What is interesting for this mechanism, and many teams and team members and students, initially find it difficult to work with such mechanism, is that the gear wheel is not rotating. The worm gear is but the gear wheel is not rotatitng, because it is connected to an axle and the way this whole mechanism works is the following. I'll start the program and if I now try to move the worm gears you can see that the whole mechanism on the inside moves.

The worm gears work with the gear wheel and they move the gear wheel and the gear wheel is connected to an axle and the axle is connected to the whole mechanism on the inside so we actually can move the whole mechanism on the inside. And these are the 2 interesting things about this mecahnism. First, we can control different axles and the way we control them is that we choose the inside gear wheel to work with one of the other gear wheels and how do we do this, we move this inside gear wheel.

We move and now we work with the other. Let's move the whole inside mechanism to the end and we are working with the final gear wheel. As a recap, we can control the position of the inside gear wheel by moving, rotating the worm gears and thus moving the whole mechanism and from there we control which gear wheel is working and which axle is rotating. We can have 1, 2, 3, 4 different axles controlled and we can control them forward and backward. This means that with 2 motors we have 8 different movements, which is great for this mechanism. A few more interesting things will be shown in the third part of these video series.