# VEX IQ Crossover. Two degrees of freedom introduction ProPreview

What is a single, and what is two degrees of freedom

• #555
• 22 Sep 2017
• 3:56

### Two degrees of freedom VEX IQ Crossover attachment

Attachment for lifting object, especially hex balls if you have them from the Crossover competition.

### English

In this section of the course and in this class we'll start with a new attachment and we call it a two degrees of freedom attachment. It works in the following way. We can use it to lift different objects as in the case of the VEX IQ Crossover these are the hexballs. So, if we have the hexballs on the attachment we can then use the gamepad to lift the hexballs.

Like this. In the following few sections we'll enter into more details about the attachment, its purpose, how it works, how we can improve it, what are the advantages and disadvantages of this attachment. Let's first start with the subject of how we call this attachment and why we call it a two degrees of freedom attachment. Looking at the attachment it has two motors. We have one motor here and we have one motor here. And we have a system of gear wheels and levers. The way it works: With the gamepad we use the default driver control program and we have the buttons right here on the left side of the gamepad and right here on the right side. With the buttons on the left side we control the motor right here at the back of the attachment. With the buttons on the right side of the gamepad we control this motor and from there this system of gear wheels like this. We call it a two degrees of freedom attachment because actually this attachment can move in two different axles. So, it can move up and down like this but it can also move forward and backward like this. And of course, you don't have the full range of motion because the whole attachment is limited with the system of gear wheels and with the levers but we can have a very interesting movement with this attachment. Again, we can move it like this - up and down and forward - backward. And we can even synchronize these two movements and control the attachment in the following way. Now, for the degrees of freedom that's a term from Machine Learning and it's an interesting term and we'll enter into more details in some of the next videos but for now as degrees of freedom just think of the number of motors that you have. It's not the correct definition but the number of motors that you have will give you for this attachment the number of degrees of freedom.