I was out flying with a friend who is not current and was looking for a little time in the 180 with me being a safety pilot, kind of a Bi annual kind of thing. He was way behind the 8 ball as he has not flown for a few years and as we know you got to be on cue with the 180....anyway after some interesting landing we thought it would be best to do some air work, after some slow flight our flaps were stuck at about 20 degrees and this is what I found. It took me a good 3 days to fix.. Needless to say cleaned and inspected all brackets, rollers and tracks..