We are turning some aluminum pulleys for 6 groove serpentine. We are using an iscar insert ($38ea) and we have to take off the Ti coating on them so they wont gum up on the grooves in aluminum. We had to have a special holder made for the Iscar inserts to amke sure they have a better angle but yet we are getting chatter. We have tried 50SF and .002 and we have tried up to 800SF and .010 and we still get noticable chatter. Who makes a GOOD poly V cutter for aluminum?