I am trying to study a simple porch glider type joints. I am very new to sketchyphysics 3.2 plug in, and it is installed in sketchup version 8. I started with an upright attached to the floor. Then added 2 hanging arms with hinges connecting them to the upright. The 2 hanging arms swing as they should individually, But when I try to attach the horizontal arm to the 2 hanging arms with hinges everything goes haywire! I have included the file for a sample of what I am trying to study. This idea could be a good basic tutorial for beginners. Please help me learn.
Basic porch glider joints