Thanks mr Davidson, I am not alone!: as I'm out on a limb where I live, no framers about here (good for business!), I had to develop my own methods, using the Japanese practice I experienced as a base. (Centrelining).
The English framers I have worked with since say the method I have worked out is OK for what I do (mainly roof framing) but not so good, for something like a cruck frame x 6 for example.
However, .. mostly I don't have to lay out the frames before cutting, which in a one-man outfit is important timesaving and back-saving. I think that is more onerous than the lengthy process of lining out, but which is also a useful selection process.
I don't know how other people do it, but I establish, from the initial centre line, chosen for various reasons on a particular facet at a particular orientation, a vertical plane transferred to the opposite face, then this is squared to an horizontal plane, ditto. In all the calcs, I am envisioning these planes then imposing the sides/section of the timber on them, offsetting etc.
I only use the sashigane (metric, though I have the Japanese one) + a calculator, and a scribe. Not much in the toolbox: (and you can stick the sashigane in your belt: I don't own a western roofing square:too big) something which originally impressed me by my Japanese carpenter friend: not much to carry, but so much to utilise.
I use the trig to transfer back to numerical settings on the square, in metric it's so easy to multiply up etc.
I can't understand why more carpenters don't use such an easy method which is only dependent on a few formulae, and a basic understanding of triangles.
