We have built the system for two and also about 5 times the set screws trying to fix. The bars from floor to ceiling hold properly, but the crossbars slip up with us always back down. I have several times tried the set screws securely tied down, and I also now have packing tape underneath geklebt- unfortunately slipping the top two crossbars down anyway. The lower crossbar rests on the joints and can not dislocate. So we try it again today with the tongs, because practically it is already, but if it ever slips, only annoys you with it around.