Moving a pivot point

Going thru some tuts on Bongo and came across this excavator. Was wondering how the pivot points are set on the arms? I see that nulls can be set as pivot points but these pivots do not seem to be points.

Thanks all!

Fair enough, thanks. Got a new question. When will this green object change? I have given these 2 objects different joint properties like hinge and telescopic yet the icon for it stays a green cube. What doe the green cube mean as well? Thanks.

The green object will not change unless you change the object type in Rhino. That green icon tells you what kind of object you have animated, in this case an extrusion.
To see the IK-view you need to press the IK-button. Please see:

I cannot get this to work…pivot point in gumball stays in the center of the part

Don’t confuse the Bongo pivot with Gumball. The gumball can only be used to perform Rhino manipulations. Bongo has its own specific pivot. Collaboration between both will have to wait for Bongo 3.