The hardest work i ask my stand mixer to do is knead dough. when under load of two loaves, it makes a loud grinding noise and deposits what look like lead pencil filings on the collar of the dough hook. have i putchased the wrong mixer or is mine just a lemon? the noise is present even if beating egg whites--but not the filings. it has been oddly loud since it was unpacked.

Food Mixers - KitchenAid - KP2671 Professional 6 Series Stand Mixer