I'm not sure where I got the plans from now, I just checked Beesource and they weren't on there, but I built some 5 frame medium swarm traps that had a SBB with a removable bottom cover. Catch you swarm, bring them home, and once the queen is laying well, remove the bottom board. I got the plans somewhere on the internet but basically a nuc with a migratory top that could be hung from a tree.