To design for a segmented turning:
- Draw the form for your turning on graph paper
- Decide on the number of layers of rings to be used.
- Determine the width of the segment by the drawing
- Determine the thickness of the segment by your drawing
- Decide on the number of segments per ring.
- Use the formulas below to determine the shape of the segments and splines for each layer
Closed Ring Segment Formulas
- The length of segment formula = ((R*2*3.14)/S)*1.024
- R = radius to outside edge of turning
- S = number of segments per ring
- 1.024 = fudge factor
- Angle of end cut = (180 / N# of seg.)
Example=: 4” radius ring, 18 segments per ring
- length = ((4*2*3.14)/18)*1.024 = 1.429”
- angle = 180/18 = 10 degrees
Open Segment Ring Formula
- The length of segment formula = 70% of the closed segment length or ((R*2*3.14)/S)*1.024 *0.7
- R = radius to outside edge of turning
- S = number of segments per ring
- 1.024 = fudge factor
- Segments for an open segment turning should be between 66% and 70% of closed cut size. (The formula above would be used for a segment with 70% segment.)
- Angle of end cut = (180 / N# of seg.) * 0.7
(The above formula is for a 70% segment)
Segments Closed Cut Angles 70% of Cut Angle 66% of Cut Angle 6 30 8 22.5 10 18 12.6 11.9 12 15 10.5 9.9 15 12 8.4 7.9 14 12.86 9.0 8.5 16 11.25 7.9 7.4 18 10 7.0 6.6 20 9 6.3 5.9 24 7.5 5.3 5.0 26 6.92 4.8 4.6 28 6.43 4.5 4.2 -