I have purchased my lumber and materials but here's my problem.
1) The Langstroth plans I have from beesource show an external dimension of 19 7/8"L X 6 5/8"H. The internal dimension is 18 3/8"L a difference of 1 1/2". In the deatail they are shoing an additional 3/4" board on the inside which should create the frame rest, but the problem is they show a 3/8" deep frame rest, 5/8" to the top of the box, and 3/8" thickness, the numbers don't add up.
I never paid attention to those inner numbers. Use the out side dimensions and you will be ok.
If you look really close at the measurements in the circle, you will see that the frame rest is 5/8" deep. The 3/8" is the width of the frame rest, and the width of what is left of the wall. The 3/4" is the thickness of the board before cutting and where it is joined together. You have the option of cutting the frame rest all the way across or not. It is easier to do it that way.
2) Also, I'm building all mediums which should have an overall height of 6 5/8", less the 5/8" for the frame rest, leaving 6". The frames are 6 1/4" which would leave them sticking out the bottom of the box.
I didn't build any mediums, but I would hazzard a guess that is the depth needed on the frame for the bee space when sat on another hive body. I could be wrong on that one. You might need to make adjustments to it
3)If the Langstroth measurements I have are correct do all the boxes rest on only 3/8". Seems like this might be a little tricky to line up?
That 3/8" is only on the frame rest side. The other two sides have a full 3/4" to play with.
4) Using all mediums/10 frames, what would be the best frame/foundation to use. I want to use a 4.9mm small cell foundation because I like the info from MB, Brian, and others regarding mites, diseases, etc...
Then go with 4.9mm.