I've used this machine with success for about 15 years. Its good enough for me as I only string my racquets. I had shoulder surgery last October so haven't used it since then. When I got it out, the base clamp will not lock closed. As shown (hopefully) in the video. Like an idiot, in trying to fix it, I ended up breaking the other one too. There appears to be a big washer, then three smaller washers, one with ridges. Does anyone have any clue how I can fix these? Thanks so much for any time.