turning a one piece crankshaft using a 4 jaw chuck

[Aquarius21]

Greetings, Well, in the wee hours of the night when I could not sleep and the mind was overactive
I pondered if one could turn a one piece crank using a 4 jaw chuck. I have located some internet
articles but I do not have a faceplate that accepts lathe dogs. I do have some parallel metal clamps
that could be used with the face plate but having so little time to actually hit the shop I wondered if one can accurately offset thecrankshaft in the 4 jaw so that when the bar is periodically reversed in the chuck one maintains the proper 180 degree offset for both throws? My thanks again, Quincy

 

[bearcar1]

Aqua', I do not believe that you would have much success using a 4 jaw chuck for that purpose. I'm not saying that it could *not* be done that way, just that it would take a great deal of EXACTING indicating to achieve the desired, acceptable results. You would be far better off making up a fixture jig from some round bar stock to hold the crank in while machining the journals. Of course the most accurate method would be turning between centers of the headstock and tailstock.

BC1
Jim