Would you please tell me how to make a rubber band?
If you're allowed to use Recipes, the Recipe bandsome (http://fold.it/portal/recipe/43861) is helpful. You can tell it exactly which residue and atom #'s you want to connect, and if what it gives doesn't look right, you can remove all bands so far or just the latest band you added. Using CPK and Stick to display your protein is helpful with this Recipe.
Tutorials 3-2 and 3-3 use rubber bands. http://foldit.wikia.com/wiki/Tutorial_Puzzles has videos about them.