I tried top bars last year and had a comb collapse as well as comb stuck to the sides. When I started, I made my hives so they fit deep frames. That way if t didn't like it changing would be easy. That said I now use complete frames without foundation. I can buy a rough cut 1"x10"x8' for $4. With that, I can make top bars for frames by cutting the comb guide with the router and ripping it with the table saw. I had a guy come with a portable saw mill and had him cut a 1 3/8" thick board for frame ends. If you want to make top bars fast you need to start with the proper thickness. Unless you have access to a mill that will make custom cuts that isn't easy to find. I should have also had him cut a 1.25" board for ends as well. For brood nest frames I use a standard 1"x??? Because they are planed to 3/4". Works perfect with 1.25" ends in the brood nest. I think if it were me, making top bars for top bar hives, with what I know now I would make them 1" wide. Then I would make 1/4" and 3/8" spacer strips. That will make building them quick and easy. It will also give the most flexibility for expanding the brood nest or what ever.