Jon Nazareth
Western Thunderer
Here’s the under frame. All of the holes were drilled before assembly ie, while all of the components were nicely flat and easy to get at. The building frame/simple jig used is of the type that I use for all of my building these days. They are cheap and simple to make and importantly, they do the job. There is an upstand on each of the buffer beams whose height is the same as the thickness of the floorboards i.e., the floor will end up the same height.
Jon
Jon