Just in case this happens to you. Monday I used the k50 with drum adapter and couldn't take the drum adapter out, used it yesterday with 5/8 cable and the cable was getting stuck in the machine....couldn't push forward or backwards. Opened it up today...super easy, 5/16 allen wrench...and found alot of surface rust on the face of the inverted cone and chuck. Cleaned the rust up with scotch brite pad, put some wd40 on there and we're back to working. Took maybe 10 minutes.