A few years ago, Autodesk Inventor introduced joints to the assembly environment. This was a little confusing at first so I kept on using the normal constraints to assemble things but then I started getting into dynamic simulation and even though you can use the normal assembly constraints to setup the assembly simulation you eventually have to get stuck into joints to complete the simulation.

After a bit of oohing and aahing, I started to slowly get it. In normal constraints, the idea is that everything is free floating and the degrees of freedom need to be taken away. So there are 6 degrees of freedom. There are 3 in translation along the X,Y and Z axis and 3 in rotation around the X, Y and Z axis. When you insert a constraint you take away some of those degrees of freedom. For example, when you apply a mate constraint between 2 faces you are taking away all the rotation degrees of freedom as well as 1 degree of freedom in the translation axis. So you still have 2 degrees of free.

When creating joints in the dynamic simulation environment the parts do not have any degrees of freedom. They need to be given degrees of freedom by applying joints to them. The joint that would be equivalent to the previous constraint I mentioned would be the planar joint.
In my next blog we will take a closer look at the different joints that you will use when performing Dynamic simulations in Inventor.