I have a Husky stick edger. The other day when pull starting it, the head just fell off. I can't figure out if something is missing (doesn't look like it). I can't even see how the two parts secure together. In other words, on my string trimmers, there is a bolt that runs through a collar. Loosen it, and the head comes off. But I don't see any kind of a collar or bolt that held the head on the edger. Anyone with knowledge of Husky equipment have any insight? Thanks in advance.