The Wood Turner’s Selection Guide, Part II: Choosing a ChuckComments (0)
After choosing a lathe, getting a good chuck is probably the next important task. The most popular manufacturer, Nova Teknatool, has three main models of four jaw scroll chucks (smaller to larger): Midi, G3, and SuperNova2. Most of the chuck bodies accept an adapter matched to the lathe spindle. Some versions have a dedicated thread specifically for a certain spindle size. While dedicated is less expensive, the adapter is more versatile because it can be changed to fit a different lathe. With a little research, matching the lathe spindle size to the adapter is straightforward. Some terms to know: Spindle- shaft through the headstock which rotates, Swing- largest diameter which can be turned, Scroll Chuck- all four jaws move in union when adjusted, TPI (threads per inch)- the number of threads on the spindle in one inch.
The Midi chuck is best suited for bench top lathes with swings between 5” and 10” and horsepower between 1⁄4 and 1⁄2HP. Adjustment is done with Tommy Bars, or short steel bars which fit in holes on the chuck and are rotated counter to each other to tighten or loosen. The adjustment process can have a learning curve to master.
The G3 has a geared key that fits into the chuck body and turns to adjust. It is best suited for swings between 12” to 14” and horsepower between 3⁄4 and 1HP. The chuck or adapter will have a set screw which locks the chuck onto the spindle– useful so the chuck won’t spin off when sanding in reverse.
Midi 50mm, G3 Soft Jaw, SuperNova2 70mm
The SuperNova2 is much heavier and is designed for lathes with a 14” to 20” swing and 11⁄2 to 2HP. Adjustments are made with a T-handle hex wrench and it can also lock to the spindle.
One of the great benefits to using a chuck is the ability to quickly change the holding jaws to fit a certain project. Every chuck comes standard with a 50mm set, and jaws are available from 9mm up to 130mm in a variety of styles. Specialty options include plastic jaws which can be custom turned to fit a project and cole jaws used to hold bowls when removing the tenon. Each jaw and carrier on the chuck are sequence numbered so the jaws align properly when opening and closing.
The important aspects to remember are the size of the turning project, capacity and spindle size of the lathe, and desired jaw configuration. Since it can be confusing to know how each jaw set works with each chuck, a chart is available which showcases all of the options. Most chucks work well for future expansion, just get a different adapter or jaw set.
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