So far you can only emit simple objects that dont have any properties or connections. It might be possible in SPIV.

Look here: http://www.sketchucation.com/forums/scf/viewtopic.php?f=61&t=17350

sorry for that misleading post

Something like the magnet switches from LBP could achieve all kinds of stuff like this; they're basically proximity switches. If we were able to use entity names within script, something like "if(proximity(box1,box2)<500);1.0;else;0.0;end" would do it. The way I've written that is probably stupid, but you get the idea... expanding on this, you could have sketchyphysics know an object's position in relation to the origin, something like "x/y/zproximity(origin,box1)", its x/y/z speed and how much it's pitch/roll/yawing. Also use joint names in script, like "0.5-hinge1000", for levers etc. If it's possible, that'd be awesome, if it's not, never mind.

I have gotten it where a pin will fall into a shape and can be moved. Well sorta. The pin doesn't stay in there very well if i drag it around too fast( make sudden movements) and if I stack the blocks on top of each other, they just fall into the one below it. And they go through the floor some if they aren't flat on it. I have attached my model. Ya, I found the attachment button. Just press play to see what i mean. So please tell me what I need to change. Sorry it doesn't have a name

Major features in the next release will be magnets, gears, more control over joint positioning and keyboard/mouse support. Also a new way of allowing jointed objects to be copied. No ETA yet.