Amazing reply, thank you so much!

Hello there, I am loving MSPhysics, although I am finding limited tutorials and have gotten stuck trying to make a basic monitor arm (robot arm pretty much) I understand the tools yet I am struggling to understand how to get 2 or more servos on one arm. For instance, I group my first arm to a servo, yet I cannot use the joint connection tool further into that group onto the next arm for it to stay relative to the first arm. below is a file submitted which works perfectly but I am trying to understand how he did this, is it obtainable without scripting?

here is a working example of what I want to know: https://3dwarehouse.sketchup.com/model/c3eabd528e13297ddf6d65aa66a5c53/Robot-arm

thank you!