Acid impurities, such as carboxylic acid-terminated polymers, are removed from macrocyclic oligoesters with ion exchange resins, resulting in macrocyclic oligoesters that are substantially free of acid impurities. In one implementation, a method is provided. Condensation of a portion of the gas generated can be combined with the solids for continuous removal of such solids from the enclosure. The micro-mirror is in close proximity with the timing circuit. The second gear is engaged with the cam for rotation.