George, that's a great project, you've months years and possibly decades of fun ahead
There are a number of things that'll challenge and the crankshaft is one of them....fortunately as others have proven none are insurmountable. i'd like to just double check what is meant by built up vs one piece, do you mean silver soldered fabrication vs one large dia bar? if so, I'd say celebrate.
Mine came with the silver soldered fabrication. I've found turning from a spindly silver solder thingy a disaster and i quickly pretzel-ed it. In starting from a solid bar there's enough material strength that by going in the right sequence you its not too bad
here's the pretzel
here's the one made from solid (excluding webs, they are added after)
There's a specific order to follow.....
- using the mill and x/y coordinates drill 4 centres (journal and 3 pins) in each of the ends - centres being aligned to one another
- machine each of the pins
- as you machine each pin, place an acurately made spacer in gap - this is critical
- used duct tape around the journal to ensure the pin stays put (handy mans secret weapon)
- after the three pins are done, turn the long shaft dia next to the tailstock - tailstock provides decent support for this
- reverse the shaft and using a collet, chuck the shaft portion just turned. Since the greatest overhang is now inside the headstock, its a little more rigid to turn the center journals.
I ground two parting tools as a left and right and knife tools - with an appropriate radius between journal and side. to pick up a cut as you change from L to R tools, use permanent marker. come in until the tool scraps off the marker but no metal. This is tricky stuff machining the pins, you have reach a long way in in a narrow restricted space with a flimsly set up - light cuts and patience is the order of the day. are after all turning is done, mill the offsets from round to flat
hope that helps
btw - did yours come with the cylinder drain cocks? always wondered if they were supposed to be part of it. mine came sealed as well but i'm less than convinced the faster set is correct - there is an odd collection of fasteners, in no way follows the list....like i'm almst done and there must be 50 extra ba studs and nuts yet there only a couple of the requried 7ba counter sunk screws