making an auxillary wood lathe shaft

I should like to make another shaft that has the same thread as my jet lathe. The problem I have is,I don't know how to center a pc of all thread to which I will attach a shaft. I want to put a 1-8 thread pc on a 3/4" shaft so I can use my lathe chuck... Thks,pw.

Why not try something like this:



http://www.pennstateind.com/store/LA3418.html?mybuyscid=3681883637&utm_source=mybuys&utm_medium=webrecs&utm_campaign=mybuyswebrecs