How to Make a Longworth Chuck with Ron Thompson

Updated on: Published on:
Two men in a woodworking shop holding wooden parts for a Longworth chuck on a workbench with clamps and a router nearby.

Woodworking Adventures is back with a new blog site and our first story is in the shop with the “Turning Tuesdays” guys with another home spun turning project. Ron Thompson shows us how to make a self-centering Longworth Chuck. The Longworth chuck was developed by Leslie Douglas Longworth of the Hunter Valley Woodturners in Australia in the late 1980′s. Featuring a self centering mechanism that easily and quickly adjusts to the size of your turning by using a pair of disks which rotate against each other, drawing in and out the attached rubber jaws on a series of opposing arcs.

Stack of Baltic birch plywood sheets in various thicknesses and dimensions with item numbers listed

Starting out with 2 separate birch plywood pieces, Ron makes this particular chuck out of 3/8″ ply, and 3/4″ ply.

Two wooden discs with layout lines and a metal faceplate mounted for making a Longworth chuck

A 1/4″ birch dowel is glued in the center of the 3/4″ plywood. Both plywood pieces are turned to a specific diameter depending upon your individual lathe requirements.

Hands holding a wooden blank with a circular cutout, marking it with a pencil in a workshop.

In this build, a holding fixture is made to fit the 1″-8 diameter faceplate.

Hands holding a wooden circular faceplate for a Longworth chuck in a woodworking workshop.

The fixture is clamped to the workbench using Bessey 6″ F-style clamps.  The faceplate and chuck assembly are clamped to the fixture located by the faceplate hole.

Hands marking concentric circles and arcs on a wooden disk for Longworth chuck layout.

Circles of 1″ and 2″ diameters are marked from the center of the chuck, followed by a circle drawn 3/4″ in from the outside edge.  Another circle is drawn in between that circle and the 2″ circle. In this case 6 arcs of 4-3/4″ for the slots are drawn with a compass as shown below.

Using a router to cut concentric circles on a wooden disk for a Longworth chuck assembly.

Ron uses an LED flashlight to help view the centering pivot cross points through the router fixture for using a Round-Blade Awl to route the 6 slotted arcs.

Router cutting curved slots into a wooden disk for a Longworth chuck, next to a finished disk with spiral slots and a

Ron uses a DeWALT Plunge Router to create the radius slots using a Whiteside 1/4″ diameter spiral router bit.

Hands adjusting bolts on a wooden Longworth chuck faceplate with curved slots for positioning clamps

In addition thumb holes are machined through for opening and closing the chuck with a 1″ forstner bit.

Hands assembling two wooden circular plates with adjustable bolts, part of a Longworth chuck in a woodworking workshop.

Sand the rough edges and add finish if desired.

Complete build details are in the video:

This exercise was making a 6-slotted Longworth Chuck.  

More sawdust will be flying from Codger Lodge with another “Turning Tuesdays” episode on “How-To” build your own Spin-A-Way Tail Stock, so stay linked. We hope you like our new blog site design, so let us know what you think and tell your woodworking friends all about it!

Back to blog