Wanted to make a collapsible katana, and saw good reviews for this model. Needless to say that I am enjoying it. I might be in the minority here, but the top blade comes off when opening the katana. I fixed it by applying hot glue and inserting again to a height where the blade should stop. When the glue expanded and solidified, I collapsed the blade to make it loose from the walls. Now the top doesn't fly off when I swing my katana.