It works fine with the dart... Does it get hung up when spinning? If so take all the magnents out and stack them in your hand. The magnetic field will only let them stack one way. Then put them back in so that the polarity is opposite as you go around. Or in otherwords, take the first four off one end of the stack and put them in every other slot making sure that the polarity is the same. Then flip the roll of magnents over and put them in the rest of the holes. This way the polarity alternates as you go around the disk. It increases the motors pull on the drum and you should have no problems.