# Turning a smaller diameter between two larger diameters?



## mfarris (Nov 13, 2013)

First off, I'm a newb to machining and model engine building.  My question is what is the best approach to turn a smaller diameter in between two larger diameters (two shoulders)?  For example, a journal on a crankshaft.  What is the proper tool to use?  A parting tool?  If so, how do you get the tool perfectly square so it will cut two square shoulders and the smaller diameter will wind up the same diameter all the way down the length of it?  It seems to me that will not be too easy to do on a part such as a crank that requires pretty tight tolerances.


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## kvom (Nov 13, 2013)

http://www.homemodelenginemachinist.com/f31/multi-cylinder-crankshaft-machining-tutorial-5011/


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## mfarris (Nov 13, 2013)

Thanks kwom, that is a very, very helpful link.


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