Maybe 6 months later we can work this out.... So I recently started to work on this again. I got my model to play midi sounds with your drum example codes (I like the drum example even though you say the piano one is better). I need a way to tell the emitters when to fire, and currently the way you have it in your models seems too time consuming (unless you didn't type it out one by one). And by not using your way ("10:46"=>[[...)), how can you change instruments? Does the new version of SP help with this? I'm sure you'll have more time now.

Seems good... I'll use it for now. I was thinking maybe a website that has only sketchup/sketchyphysics files uploaded? I don't need it though.

My suggestions are: -don't let each axle turn independently, if a wheel catches it torques around really bad. And its less realistic. -don't have the ends of the rails beveled, it gives the wheels something to catch on (counter intuitive I know). -use a simpler model to get everything right. You can use the same dimensions without eating up RAM and your video card. Also why is the engine articulated behind the cab?

That worked. thanks! i just want to know the last part of my original post: @unknownuser said: Also, is there a way to delay a emitter? Like, I press the key and [so many frames] later it starts emitting. I'm using the same code: (0.0-key("e"))*-80 rate:1 I suppose there's no way to keep emitted objects going on a straight line at the same speed?