# VEX IQ Crossover. The math behind grabbing a hex ball with levers attached to gear wheels. ProPreview

• #533
• 09 Jun 2017
• 1:30

### English

There is a mathematical model behind our attachment. I prefer not to discuss the mathematics in most of the attachments but this one here is very easy and it's very straightforward and we'll use a geometrical model to actually discuss why the attachment needs to be aligned to these two wheels and how we are making sure that it stays on the same plain. Here is the math, just the theory. First, we have this beam here and the length of this beam is fixed. No matter how we move this whole attachment and what we do with this attachment this length is fixed. Then we also have the length of this whole beam fixed. And we are interested actually in the length between this hole and this hole and it stays fixed. So, these are two sides of a single triangle. What we should do is to synchronize the two wheels so that the last side of the triangle stays the same as length and it is fixed. And when we have the three sides of the triangle and they are fixed and they don't change as length the whole attachment will move in the same way. That's the geometrical theory behind this attachment.