The cylinder on my 36 caliber black powder revolver does not spin when you cock the hammer any ideas?

The most likely cause is the spring on the hand (the part that is attached to the hammer and protrudes through the frame to the cylinder) is broken or weak, or the hand is worn or broken. Remove the cylinder and cycle the action with your finger over the slot that the hand is in, if it has pressure against your finger and moves upward then check the back of the cylinder to see if the cogs are worn or obstructed.