most of us has tried that one rod thats mounted on another rod, secured with a bolt, maybe even with a measuring gradient still intact.
it kind of works, but once you lock that thing in, and you have a piece thats done sawing, either it will be jammed stuck, or the distance will be skewed either by the band saw grabbing the piece you just sawed or when you try to get it dislodged.
so i put this little device together

20mm thick piece of steel with hole in it, bolt going through that to keep distance on the rod coming from the band saw
then 2 pieces of plate with holes in, bolt and nuts through to act as a basic hinge (this can be done prettier)
and finally the swinging piece of flatbar with a little bolt on it for easy controlling
in neutral position the flatbar stands up, then you swing it down towards you and the flatbar doesnt block whatever youre cutting, you swing it down before activating the bandsaw blade once the steel youre cutting is locked in tight
its also really cool because you can carelessly push - even quite large pieces of steel directly into the stop, and the distance stays put, bigger bolt/ wider piece of plate = easier to clamp down tight

as a bonus, the way i made it when its not in use it doesnt get in the way as it stays below the height of the rollers

distance bandsaw.JPG