Help with Armatures

[dfoley75]

Hello,

I've watched a number of videos on Youtube and also read a lot of documentation, and have not found an answer to these questions. I now know enough about the basics of using armatures, but still can't figure out to do what I want.

I am trying to make a simple 2 armature linkage, but constrain its motion in specific ways. So there will be 3 pivot points, and 2 arms. One pivot point will be fixed. One arm will rotate about this point. It will "pull" the other arm as it rotates, but I want the other end of the 2nd arm to only travel along a straight line (like the X axis). So the end of the 2nd arm will travel along a track.

So here are my questions:
1) How do I fix the one end of the first armature so it can't move?
2) How do I constrain the length of my armatures so they are fixed?
3) How do I constrain the motion of the one end of 2nd armature so it can only move along a straight line?

If you can point me towards some documentation or a video that covers this I'd appreciate it, because I haven't been able to find it. Thanks.