As I plan to breed queens this year, I looked online for a set of mini nuc blueprints but I didn't find much.
The Beekeeper's Workshop (TBW) had very nice plans for a four chambered mini nuc. You can find these plans on their website and on YouTube. I do plan to give these a try sometime but for now I wanted single nucs.
Don the Fat Bee Man has a great design as well (see his YouTube Channel) but in his video, the dimensions don't add up - and the plans are for a medium deep nuc (which might save a lot of wood).
Mann Lake sells a Styrofoam mating nuc but they cost $20 and are very small.
What I like best about the TBW four chamber nuc was that it could be stacked on top of a standard hive super. What I like best about Don's mini nuc was that it is made from scrap wood. I also like Don's better than TBW because it uses a half size 9 1/2" frame rather than 9 1/4" - this allows you to place two end-to-end in a full-size hive to draw out the wax. (You can do the same with the 9 1/4" but it makes a bigger gap.)
In my first attempt I divided the length of a full supper by half, I used 1x4 material, and used TBW 9 1/4" frame but this made the inside dimension of the nuc too short and didn't leave room for bee-space.
On my second attempt, I used the same outside dimensions but I used 1/2" lumber on the two ends (still used 1X4 material on the sides) and then I was able to use Don's 9 1/2" frames with just the right amount of bee-space.
I'm building these out of scrap wood. I use (3) - 1X4 on both sides (These are of course 3/4"X3 1/2") and I use (4) - 2 1/2"x1/2" boards on the front and (4) on the back (I ripped these boards from some 2 1/2"x3" stock I had). The staggered pattern locks all the boards together and makes a pretty solid box. I also use nail and glue on all my joints.
Now some beekeepers will freak out because all these little boards leave gaps and cracks. Relax! I found that if you brush each crack with a thin layer of glue and then just rub sawdust over them and into them, it all seals up tighter than Dick's Hat Band - I didn't invent this process but I like it!
So here is my blueprint - I drew it with Microsoft Excel and then imported it to Paintbrush so you will have to play with your print scale if you want it to be to scale. Otherwise, here you go: