Tips on Segmented Turning

This type of turning requires a basic amount of maths and geometry. lt requires some basic machinery to prepare the wood and cut angles.

To start, you must design the shape of the vase or bowl on paper. Once the diameter and the height is decided, which must be within the scope of your lathe, you can then decide on the thickness of each ring and how many segments for each ring.

Now comes the maths, "PI" is the value used in your calculations. lt equals 3.1416, to find the circumference the formula is 3.1416 x the diameter. To get the length of each segment you divide the result of the sum above by the number of segments you want in each ring.

Say one of your rings is 10 inches in diameter and you want 12 segments in a ring, then it would be calculated as 3.1416 x10 = 31.416 by dividing that number by 12, the length of the segment is 2.618 inches, taken to the nearest decimal 2.5 inches. Now comes the angle you have to set your saw for the mitres. There are 360 deg. in a circle, you have chosen 12 segments in your ring, so 360 divided by 12 is 30, but you have two bevels together so the angle of your saw is 15 deg.That is the basic formula for your calculations for all diameters.

It is much easier if you can work in millimetres but it is up to individuals.

You might like to look at the Segment size calculator

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