Remounting Bowls and Platters with the Longworth Chuck

The Longworth Chuck is one of my favorite remounting options for turned bowls and platters. It’s fast and easy to use and can be mounted in a chuck using standard 2-½” dovetail jaws. In this post (and video below) I’ll explain how to use the Longworth Chuck, highlighting the advantages and limitations of this versatile chuck.

Choosing the Right Chuck

I usually opt for the Longworth Chuck for remounting workpieces due to its convenience. It mounts directly into the chuck jaws, eliminating the need for frequent jaw changes. However, the Longworth’s lower RPM limit (600 RPM in this case) can hinder efficiency, especially during shear cutting and scraping. There are alternative options like Vicmarc Adjusta-Jaws, which offer higher RPM capabilities but require more setup time. The Longworth Chuck is a great choice for smaller pieces and when convenience is prioritized over lathe speed.

Mounting Techniques for Optimal Centering

When mounting your bowl, I recommend placing the piece on the lathe bed, positioning the Longworth Chuck over it, and then tightening the grippers. This method allows for better centering. Once the piece is centered in the chuck, tighten the grippers in a star pattern to ensure even pressure and prevent the piece from being pulled off-center. Finger-tight is sufficient; excessive force can actually decenter the piece and split the rubber grippers.

Balancing Speed and Precision

The Longworth Chuck’s lower RPM limit necessitates slower feed rates. Rushing the cut can cause the piece to come out of the Longworth Chuck. Small cuts and controlled movements are crucial. While the lower speed is a drawback for the turning process, it becomes an advantage during sanding, as the 600 RPM limit often aligns perfectly with sanding speeds.

Support and Safety

Supporting the workpiece with the tailstock is paramount during the turning process. Keep the tailstock engaged as long as possible when turning. Once you are ready to turn away the nub at the center of the bowl take light cuts to prevent the piece from coming out of the chuck.

Addressing Challenges

There are some minor challenges when using the Longworth Chuck. Noises emanating from the chuck or the piece shifting in the chuck indicate that it’s under too much stress. When this occurs, lighter cuts or a change in cutting technique are necessary. I sometimes encounter this issue when working on the foot of a bowl and switch to a scraping technique to alleviate the stress on the chuck’s rubber grippers.

Conclusion

The Longworth Chuck offers a convenient solution for remounting bowls and platters, especially for smaller projects. By understanding its limitations and employing the proper techniques, you can achieve excellent results.