I make 3 and 4 ft long taps. I turn down the shank of a tap and then I bore out the Id of drill rod. I make a .0002 interference fit and heat shrink it on. So far I have only had one tap break loose. To hold the drill rod I use a three jaw in the normal chuck position and to hold the other end of the chuck I mounted a 4" three jaw on the spindle of the front of the lathe. It works great. The only problem I have is I every now and then use my collet draw bar and have to take the chuck off to mount the draw bar opener and closer . About 20 minutes to take the chuck of and mount the collet. I haven't quite figured out how to show pictures yet but when I do I will show you the three chucks I have mounted on my lathe and use all of them at one time.