If you are into chucking like I’m into chucking, then you already know about the Longworth Chuck. I have heard that the developer of the chuck, Leslie Douglas Longworth, of the Hunter Valley Woodturners, introduced the project in the late 1980s. Being a wood turner, and a very creative person, Leslie created a fine told for multiple applications.
I built my first Longworth Chuck after seeing one in operation at a club demonstration. There are a number of diagrams available on the internet.
Along with multiple sources for parts, pieces and kits for your creation. But, what is ofton not mentioned, the use of a finished surface where the disc make contact is a nice addition
Aturning buddy of mine recently purchased one made of an acrylic based product. This reduces the twisting or warping of wooden models. Also, the plastic offers less resistance when adjusting.
Most turners see this as a tool to turn bowls and vessels around to finish the bottom. My buddy uses his to help align the rings of segmented pieces when gling them up. We are talking about perfect alignment without the hassle of clamps.
Several are made today with spacers to assist in holding.
If you would like to make a Longworth Chuck, find out the details at https://www.woodcraft.com/blog_entries/how-to-make-a-longworth-chuck-with-ron-thompson.