Project Tutorials

Chatter Finger Spinning Top

 

Spinning top Upside down spinning top
 
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Two types of chatter tools

I have two commercially made chatter tools, a Sorby and a Stewart. They’re both designed similar in that the cutter is a thin flat of cutting steel and it is held in a shaft so it can be adjusted to extend or retract the blade.

Homemade versions made from a piece of flat spring steel or even a butter knife blade will work. Some turners produce their chatter by turning the stem thin first and them presenting a tool to the wood to produce the chatter patterns.

Sorby chatter tool

The Sorby chatter tool has two straight blades that are ground to different profiles on each end. You get a straight, pointed, concave and convex cutter profiles. The shaft is beveled to angle the cutter down and has a ring and locking screw to hold the blade in place. The Sorby blades are ground at 90 degrees.

Stewart chatter tool

The Dennis Stewart chatter tool has a blade bent on the end to produce the downward angle of the blade. The blade is held in a hole in the center of the shaft by a locking screw threaded through the shaft itself. I think you can also buy a round profile cutter from Stewart. I mainly use the pointed blade for all the chatter I do. The blade of the Stewart tool has a bevel ground back to about 65 degrees.

Start of shaping

Chatter works best on the endgrain of real hard wood. I am using a piece of yellow heart because I will be coloring the chatter later and need a light color wood to start with. Other woods that chatter well are cocobolo, boxwood, ebony, lignum vitea, and hard maple to name a few. The harder and denser the wood the cleaner the chatter.

Chuck up a piece of suitable wood and start to form the bottom of the top. Turn the bottom toward the tailstock because the tip the top spins on is more important than the tip of the stem, oriented this way allows free access to form the tip to a good point.

A spindle gouge will do most all the cutting needed to turn a top.

Cutting to tip

The spindle gouge is oriented with the bevel toward the wood left as our finished top surface. The cut itself takes place just below the center of the gouge tip, the point nearest the support of the tool rest. The cut starts above center on the spindle and arcs down to the center point.

Turning top's tip

Take your time shaping the very tip. The wood at the center is moving at a slower feet per minute speed so you have to slow you tool advance to match.

Bottom of top turned

The shape and surface finish from the gouge. Keep developing the shape until you have what you want. The tip should be slightly rounded, not a needle sharp point. The first time the top drops on a hard floor the sharp point will break or deform and the top will not spin well anymore.

Sorby tool in use

The Sorby chatter tool in use. Raise the tool rest until it is about center point high. The tip angled down so the top of the blade can do the cutting. I have the lathe spinning at about 900 rpm's. I start the chatter near the center and pivot the tip to the outer edge. The cutting action is going to produce a loud squeal noise so be prepared.

Chatter patterns depend on several variables, lathe speed, density of wood, sharpness of blade, rate of blade transverse across the surface, pressure applied to wood, and length of blade extended from holder. Spend some time experimenting with all of the variations to achieve the patterns you want.

Chatter pattern close up

The chatter pattern produced. If the pattern does not look good to you, take the gouge and cut below the chatter to give you a clean surface from which to start again with a different lathe speed or other variable change.

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