Making 5 frame Nucs, for 2020

you may remember a while back I made a couple of queen castles to use next year, to hopefully raise our own queens, if that is a success, then once the two frames are full, those bees would need moving into a 5 frame nuc, to give them 3 extra frames, they could then be transferred to normal national hives, to populate the secret bee garden apairies, or get sold to new beekeepers, so the cheapest way would seem to be a correx transport 5 frame box, these cost around £8 each, but of course, are not going to last more than a season or two, purpose built wooden nucs from the large suppliers cost around £56

so, I got my Dexter cap on and started making plans, I can get 4 nucs from a full sheet of ply, with some ply left over, so for every 3 sheets of ply, I can make one extra nuc, thus bringing the cost down to £6.90 per nuc, cheaper than the correx ones