I'm not the brightest  light bulb in the crowd and this turning tool is something I've never seen. Is the piece on the tail one piece or is it a continual piece from head to tail. What is it called and what does it look like on the bench?  

 

Thanks

It looks like a pen mandrel or other mandrel that he's using. Not sure why in this application though?

 

Steve

When turning pen kits a mandrel is needed and that is what id being used here.

 

https://www.pennstateind.com/store/PKM-FLC.html

 

There are different styles but all di the d=same job.

 

https://www.pennstateind.com/store/pen-mandrels.html

 

Yep, pen mandrels come in many forms, some people prefer them when making pens or ornaments that will be hung on the tree.

Here's what it looks like off the lathe

When you turn the knurled knob does the shaft expand on the piece in the picture I provided? What is holding the piece in place?

Edited May 30, 20188 yr by Ron Altier

Just now, Ron Altier said:

When you turn the knurled knob does the shaft expand? What is holding the piece in place?

No, it simply tightens the piece between the nut and the back end, much like turning between centers, except that it has a shaft running through the piece

Looks like a bushing under the knurled knob. I would guess it is one of those ornament kits much like a pen kit. Tube glued into wood and turned on the mandrel. When turned you put on the top and bottom for a complete ornament.