Re: Selling top bar nucs?
My bars are 17.5" long but I am changing them to 19.5" but the wedge part is staying the same. I made a new nuc out of 2X boards instead of 1X and had to trim the bottoms off my combs to put them in. Went really quick with a sharp knife. I think having to trim all three sides would not be much fun, more along the lines of a chop n crop from a Lang nuc, so I would try to keep the cavity on the smaller side as others have mentioned. You might try a poll to see what width and depth of the hive body most are running. Or to find out what the smallest is.
3rd yr - 1 KTBH & 4 KTBH nucs - TF - USDA Zn 6b