I have the pulley system working perfectly. However I need to attach an object to the actual belt so it will travel back and forth with the belt. The system rotates the drive pulley/belt CW for a short period of time then reverses direction CCW for the same short period of time, and repeates. I really need help with how I should constrain this object to the belt, using mates or if it needs to be included with the belt sketch when selecting pulleys to go around. thanks!
Zack,
You can't attach a part to the belt but you may be able to use the Rack Pinion mate to simulate the effect.
Take a look here https://forum.solidworks.com/message/428483#428483 for an example that may be useful to you.