Jam Chucks: What They’re For and How to Make Them

Last Updated on October 1, 2023 by GotFunnyPictures

If you are a woodturner, you have likely encountered the problem of how to hold a workpiece while turning it on the lathe without damage. One solution to this problem is a jam chuck, a simple but effective device that allows you to hold a workpiece securely while you shape or finish it. In this article, we’ll explain what jam chucks are, how they work, and how to make and use them.

What’s a Jam Chuck?

A jam chuck is a device used in woodworking, particularly in woodturning, to hold a workpiece in place while it is being shaped or finished. A jam chuck typically consists of a cylindrical piece of wood that is turned on the lathe to match the shape of the workpiece. The jam chuck is then held in place by friction, using pressure from the tailstock or by hand, to secure the workpiece while the lathe is turned on.

How Does a Jam Chuck Work?

The concept behind a jam chuck is simple: it holds a workpiece in place by friction. Once the jam chuck is turned to match the shape of the workpiece, it is placed on the lathe, and the workpiece is gently pushed onto the jam chuck. The pressure from the tailstock or by hand holds the workpiece in place while the lathe is turned on. This allows the woodturner to access all sides of the workpiece to finish it without having to use a more complex holding mechanism.

When to Use a Jam Chuck

Jam chucks can be useful for turning bowls, plates, cups, and other objects with irregular shapes that are difficult to hold securely with a traditional chuck. This woodturning project ideas post contains a few examples. They are also useful for finishing the bottoms of turned objects, such as bowls or boxes, which can be difficult to hold securely in a traditional chuck.

How to Make a Jam Chuck

To make a jam chuck, you will need a piece of wood that matches the shape of the workpiece you want to hold. This can be a scrap piece of wood or a new piece of wood that you turn specifically for the purpose of making a jam chuck. The wood should be turned to match the shape of the workpiece, and the jam chuck should be slightly smaller in diameter than the workpiece to allow for a snug fit.

Make Your Own Jam Chuck

To make your own jam chuck, follow these steps:

  1. Select a piece of wood that matches the shape of the workpiece you want to hold.
  2. Mount the wood on the lathe and turn it to match the shape of the workpiece.
  3. Sand the jam chuck until it is smooth and free of any rough spots.
  4. Test the fit of the jam chuck by gently pushing it onto the workpiece. It should fit snugly but not be too tight.
  5. If the fit is too loose, turn the jam chuck down slightly until it fits snugly.

How to Use a Jam Chuck

To use a jam chuck, follow these steps:

  1. Place the jam chuck on the lathe and secure it with the tailstock or by hand.
  2. Gently push the workpiece onto the jam chuck, making sure it is held securely.
  3. Turn on the lathe and begin shaping or finishing the workpiece.
  4. When you are finished, turn off the lathe and gently remove the workpiece from the jam chuck.
  5. Sand any rough spots or tool marks, and your project is complete!

Conclusion

Jam chucks are a simple and effective tool for woodturners that can make the turning process more efficient and effective. They are easy to make and can be customized to fit specific workpieces. By following the steps outlined in this article, you can make your own jam chucks