Thursday, December 30, 2010

TBs TechTips 32 - LEGO Compass without magnets

New Scientist TV brings us a video that teaches how to build a Compass out of LEGO Technic elements, without using any magnet.
That might sound impossible, but the ancient Chinese worked out how to make it 4500 years ago. An ingenious combination of gears and wheels ensures allows to have a needle on a "pointing chariot" that always points in the same direction as it moves and changes direction.

Find how!...

Like at another example that we saw recently, it turns evident that ancient civilizations mastered the gear mechanisms and maths, much earlier and beyond what we might have imagined!


Wiseman_2 said...

My only question is... how do you know what direction it's pointing in the first place?
Unless you calibrated it with an actual compass... I suppose the Ancient Chinese probably used the sunrise or some such equivelant.

TechnicBRICKs said...

It doesn't necessarily meant to indicate the north. But maybe just to keep track of some initial direction.

Wonder however, if it wouldn't accumulate significant errors???

santi said...

I was thinking the same about the error accumulation. The device seems to assume a flat terrain. As soon as the terrain is uneven, the two wheels might actually turn at different speeds even if the vehicle is moving in a straight line (think of a bump for example). Assuming that roads in the past were not very well paved, I don't know if this was a very useful device. However, it makes a very nice mechanical demonstration, and it's pretty clever :)

Hunter Chiou said...

I made my car too.

Al said...

This is very clever, especially that long ago when it was created. But in the model there is a final 24t - 40t reduction. Wouldn't that make it too slow?

Unknown said...

dude... I built one like that two years ago, when I was twelve! it was smaller than this one, too. If I would have known that it would get this much attention I would have posted it on YT right away..


Alcedo said...

you can use this mechanism in a tank,to keep it focused on its target, and then use an additional motor to turn.

Anonymous said...

It is actually a kind of subtractor.


Jetro said...

Saw this some years back and the one I most remember is this page about the South Pointing Chariot, originally a chinese invention:

Anonymous said...

I built one of those things very similar when I was in 7th grade in 1984. Phil

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