The Fundamentals of Segmented Woodturning

Projects, Techniques & Innovations for Today's Woodturner

James Rodgers

• Éditeur: Linden Publishing
• Année: 2016
• ISBN:
  9781610353007
• Sujet: Tecnología e ingeniería
• Sous-sujet: Oficios técnicos y manufactureros

In The Fundamentals of Segmented Woodturning, professional woodturner and woodturning instructor Jim Rodgers provides the most up-to-date guide for any woodturner trying his hand at segmented woodturning. With an emphasis on visual instruction, The Fundamentals of Segmented Woodturning offers the new segmenter with a simple, accessible introduction to the established practices while providing advanced segmenters with all the new techniques that have emerged due to the growing popularity of the craft. Starting with the basics, The Fundamentals of Segmented Woodturning covers the essentials of tools, the steps of construction, and critical technique of accurate segment cutting before moving on to ring segmented and open segmented turning. Also covered for today's segmented woodturners are simple design enhancements to dress up any project, a bowl-from-a-board project that utilizes lamination to create mind-blowing designs, and fun techniques for simple and fast segmented pens and vessels that utilize scrap wood and can be completed in a small amount of spare time.

1 Getting Started, How It’s Done—The Basic Steps

Cautions:

• Always plan ahead, build a cutting plan and follow it.
• Assure that woods used are dry and stable.
• Build grain alignment into your plans.
• Make clean, tight joints.

Start with a simple bowl where you can follow the basic steps of ring segmentation and build a project at the same time.

Make a Drawing

Make a full-scale drawing on graph paper with a wall thickness of at least ½". (Figure 1)

Figure 1

A basic bowl drawing with an interior wall added

Determine the thickness of each ring to be built which may be the thickness of the wood you purchased such as ¾" stock. Add horizontal lines to your drawing to indicate that thickness; number each level. (Figure 2)

Figure 2

Drawing with layers indicated and numbered

For each level mark the widest exterior radius and the narrowest interior radius and record those dimensions on the drawing.(Figure 3)

Figure 3

Drawing with the min/max radii recorded on the drawing

Build a Cut List

Calculate the stock length required by multiplying the maximum radius of each ring level by 2π (3.14 x 2) to get the circumference of that ring; add five additional inches. This additional material allows for the 12 separate ⅛" saw kerfs from cutting the segments, additional material for replacing errors and enough for holding safely while cutting. Start a chart and record this information as the required material length. (Cut List 1)

Cut List 1: Table with stock length calculated and added

Subtract each layer’s minimum radius from its maximum radius and record this as the stock width for that ring. (Cut List 2)

Cut List 2: Table with stock width dimensions added

Calculate the segment edge length by dividing the circumference of each ring (2 π x radius) by the number of segments desired for the project and record this as the segment edge length. In this example we are building a bowl with 12 segments to each ring. (Cut List 3)

Cut List 3: Table with segment included angle calculated and added

Divide the number of segments into 360 (number of degrees in a circle) and record this as the segment’s included angle. (Cut List 4)

Cut List 4: Table with segment included angle calculated and added

There are several software programs on the market that can assist with the vessel drawing, completing the calculations and providing a printable cut list. These programs utilize trigonometry to accurately calculate the dimensions taking into account both vertical and horizontal curvatures that our simple “flat” graph paper cannot do. Check them out; a list of sources is in the appendix.

Cut the Segments

Rip the stock to width and cross cut it to a length to exceed the material length needed from data in the table and number the strips to match each ring number. Also cut a square for the base. (Photo 1)

Stock ripped and cross cut for making segments

Crosscut the segments on your cutting sled and bag them to keep them sorted (the next chapter covers cutting accurate segments in detail). (Photo 2)

Cutting and bagging segments

De-burr each segment being careful not to touch the cut faces. (Photo 3)

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