First clean the metal rail where the bellows slide with alcohol. With mine, old grease made it sticky. The bellows rides on a plastic guide. You can use a light lubricant like Break Free or graphite will work too. As for the setting, I never set it and leave the bellows compressed. Don't know why Beseler put bellows between the head and the negative stage. I use a dichroic color head as a light source. Maybe it's different with condenser heads.