One thing I love about woodturning is that you can make tools for making things. There’s something deeply satisfying about turning a jig on the lathe that then helps you turn a better project. Over the years, my collection of shop-made jigs has grown, and a few of them get used almost every session.

The Jam Chuck — Your Most Useful Jig

A jam chuck (sometimes called a jam fit chuck or friction chuck) is simply a turned piece of wood that holds your workpiece by friction. It’s how you reverse-mount a bowl to finish the base after removing the chuck tenon.

How to Make One

1. Start with a scrap block. Anything stable will do — I keep a few chunks of radiata pine and some old camphor laurel offcuts specifically for this. Mount it in your scroll chuck.

2. Turn a recess. Face off the end, then turn a shallow recess that matches the inside rim of your bowl. The fit needs to be snug but not so tight that you have to force the bowl on. Aim for a friction fit — you should be able to press the bowl in with firm hand pressure.

3. Shape matters. The recess walls should be very slightly tapered — wider at the opening, narrower at the back. This wedging action helps hold the piece. A dead-flat recess actually grips less well.

4. Bring up the tailstock. Before you start cutting, always support the bowl with the tailstock and a live centre. Use a piece of soft leather or cloth between the centre and the bowl to avoid marking the inside. Only remove the tailstock for the very final cuts on the base.

5. Fine-tune the fit. If it’s too loose, wrap a layer of non-slip shelf liner (the rubbery mesh stuff from the kitchen drawer) around the rim of the recess. This adds grip without damaging the bowl.

Tips for Success

• Make the jam chuck oversized. It’s easier to turn it down for a snug fit than to start over.
• Label your jam chucks with the approximate diameter they fit. I write on them with a permanent marker.
• Don’t try to take heavy cuts with a jam chuck. It’s a finishing operation — light touches with a freshly sharpened gouge.
• If you turn a lot of similar-sized bowls, keep the jam chuck. No point re-making it every time.

A Simple Steady Rest

A steady rest supports the free end of a long spindle to stop it flexing and vibrating. Commercial ones exist, but you can make a simple one from a piece of 19mm plywood cut into a U-shape that fits over your lathe bed. Mount three small wheels (old skateboard wheels work well) in a triangular arrangement so they contact the spinning workpiece. Use slotted holes so you can adjust for different diameters.

Mine is far from elegant, but it’s stopped more than a few long spindles from whipping around, and it cost me nothing.

A Depth Gauge

When hollowing, knowing how deep you’ve gone is essential. Take a coat hanger, bend it into an L-shape, and mark it with tape at common depths. Rest the long arm across the rim and the short arm drops inside. Not high-tech, but it’s saved me from turning through the bottom of more than one bowl.

A Sanding Arbour

Sanding on the lathe is tedious but necessary. A sanding arbour makes it faster. Turn a disc from scrap MDF, about 75mm in diameter, with a Morse taper tenon that fits your headstock. Stick adhesive-backed sandpaper to the face. I use mine for flattening bowl bottoms and sanding inside small openings. Make several — one for each grit you commonly use.

A Cole Jaw Alternative

Cole jaws are rubber-tipped arms that grip a bowl’s rim from the outside, letting you finish the base without a jam chuck. They cost $150-200. A cheaper option is to turn four small wooden buttons, drill a hole through each, and bolt them to your chuck jaws using the accessory holes. Pad the contact surfaces with leather or rubber. I use mine for wider bowls where a jam chuck would need to be enormous.

The Philosophy of Jigs

Woodturning is a craft where problem-solving is half the fun. Every project throws up a holding challenge or an access problem. Rather than reaching for the catalogue, consider whether you can make what you need.

The jigs you build yourself teach you more about the craft than any purchased accessory. And when something works — when your homemade jam chuck holds a bowl perfectly while you clean up the base — the satisfaction is doubled because you made the tool as well as the piece.

Most of what I’ve described here can be made from offcuts in an afternoon. Start with a jam chuck. You’ll use it within the week.