- 25 May 2017
Here is an example attachment that we've used for grabbing the Hexball. Let's say that have this one here - the orange and we have an example attachment that can move and grab the Hexball. Let's discuss in details how this attachment works. The first and very important thing about this attachment is the way the sides of the attachments are built. This attachment has two sides. And these two sides have rubber bands. When this attachment closes you can count on the rubber bands to push on the Hexball and because of the grip between the rubber bands and the Hexball you can then think of lifting and moving with the Hexball without the Hexball falling. It is also interesting that you should use probably at least two of the rubber bands. Of course, you can skip and use only one but then the grip will be not that strong and it might be possible that the Hexball will fall. So, the first thing are the two sides. Now, because there is some force applied between the rubber bands and these axles here it is a good idea to have these axles from metal. But since we need the metal axles for some of the other attachments here on these sides of this attachment we've used plastic. But if you can, try to use metal when using the rubber bands. Second important thing about this attachment is the way the two sides are moving. And it is always a good idea when grabbing to have a hand and this hand can have two prats and these two parts can just move close to each other and grab the object. But this is difficult with the VEX IQ Crossover Competition for 2016-2017 because at end we have the Goal Assembly. And when using the Goal Assembly your goal is to put the Hexball into one of these goals. Like this. And if you have an attachment that works like a scissor, what will happen is you'll not be able to release the Hexball inside of the goal and to move away with the attachment. That's why you need an attachment where the two sides move in parallel. And you should keep this in mind when building the attachment. The way we've decided to build this is with a motor. Right here we have one of the motors. Then we have one of the gear wheels from the VEX IQ set and then we have a small chain right here. And what happens is when the motor rotates the chain moves like this. And you can grab small objects or you can grab large objects. You can grab the Hexball or you can grab even smaller objects with this mechanism. So, if you need in a certain competition to have a mechanism that grabs a Hexball or another object and then transfers to another place, you can use a mechanism that looks like this.
Of course, you can find the building instructions for this attachment in the course and some of the next tasks are connected with this attachment.