Most do not do this simple trick to help keep your Collette and nut in tip top shape and lasting longer.
Every time you change bits, take the Collette out of the nut. clean the nut look for pitting, take a filler gauge or something stiff and clean all of the particles out of the the slits. do both slits... By doing this you save on bits and Colette. By cleaning the small deb-re out you insure that you are getting a good fit and that the Colette seats the bit tighter.