i called them and i was on hold for a bit but i was able to get the recommended r.p.m. with the inexpensive files i buy i usually wait until my file is starting to seem too dull to do the job. once the chicken is carried out, i drain lots of juices and add the sauce ingredients to the hot pan. most shops will send a shipping return label, and allow you to try the instrument for a week. i fixed that this week; you can see it work again in the videos above. 