and @
52telecaster i've never used an indexing head in anything i've done, but i think needing one here might be unnecessary
Originally Posted by
old's'cool
Indeed. Only a knowledgeable machinist understands what is entailed to get a good result with high probability. Then there is the question of whether there is sufficient meat in the spider to allow the required material removal while preserving adequate strength.
i understand.... the crank and targeted spots for drilling would need to be flush to a horizontal surface (drill table) to be made plum to the vertical plane of the drill travel. i've come up with a couple of ways in my head to maybe be able to do that. it's a little involved and i'd have to experiment certainly with like a scrap disk of some sort to make sure i get distance and planar relationships accurate enough. tomorrow, when i have a little more time, i'll try to explain. not too complicated, but i haven't worked out all details, either. essentially, though, the crank would become it's own indexing head utilizing a bottom bracket installed into a shell cut from a scrap from and secured to some plate metal acting as a the table.