Picking for Revolute Joints

I'm having trouble understanding how to pick and connect revolute joints. I have a set of chain links. After I duplicate the links, I'm having trouble figuring out how to connect them. I either get a javascript error or they just fall apart (not connected).

My setup seems pretty basic:

Repeat 5 times

Pick Chain instance Chain.Count-1 > Spawn Chain, Create revolute joint

I've been playing around and looking at examples in the forum. I still can't figure out why some joints will work and others won't, or won't have the correct setup. Is there any detailed explanation of how to join two objects? The manual and physics tutorial are fairly conceptual and seem vague on the actual "how to" aspect

I figured out basically that position objects on startup doesn't work. It attached the joint where ever they were in relation to each other on the layout or when spawned.

I still haven't figured out how to pick out instances when I have more than one of the same sprite connected

You should post a capx of what your project currently is, it will be easier to visualize and see what goes wrong.

Thanks for replying. Here's a capx https://docs.google.com/open?id=0B3orP9kUYRALTjFvWGhNZjRURC1tSGpyOFNvdE9MUQ

The other revolute joints work, but you'll see that it gives a Javascript error and the two paper clips don't attach to each other.

I have tried a few variations, but no luck yet

I don't know why I had so much trouble with this, but I just had a revelation.

I changed the event "Clip is overlapping clip" and it picked the two clips and made the joint.

Hm it works and looks perfect, but still have the Javascript error. I couldn't get chrome to copy and past the error message, but here's a new capx

https://docs.google.com/open?id=0B3orP9kUYRALSExSNGl0cHNSeFdmSl9RU2dHNGVxQQ

I'm still getting the error, but at least when I export to html the error is hidden. And everything looks ok.

Guess my only option is to keep studying the rope examples that I've found in search, though I can't figure out the difference so far. I'll revisit it at some point but don't want to delay other aspects of the game