i have a "hole" measuring gauge i made from hardwood by drilling holes in a block of it. (i drilled 5/16", 11/32" & 3/8" but you can drill whatever size(s) u wish) when the entire shaft will pass thru the hole, it's sized. i then put the finish on it after straightening it once again. and remember that generally speaking, the larger the outer diameter of a shaft, the heavier the spine of the shaft.
it must be noted that once the shaft will pass thru the hole, i then "finish" the shaft by sanding and steel wooling. this will remove a litte more of the o.d. of the shaft, so "11/32" will actually be smaller by a "tad". the sizing operation is to assure consistancy in shaft size diameter.
you should also straighten the shaft as you go thru the forming procedure as often as possible as some woods have better "memory" than others.
it's a time consuming, but not difficult operation, and it's very rewarding.
good luck and have fun ...
