Decorative Woodturning Artful Designs with Exotic Woods. by
Heiko Weiner
Part 3
Stepping up Your Game: A Contemporary Design. www.hwrwood.com
Summary of Part 1 Introduction to Segmented Woodturning. Armed with the contents of this Introduction you now should be able to understand the basic terminology of segmented wood turning. The resources provided in Part 1 will allow you to select your materials, perform the necessary calculations, and select the tools and equipment needed. Carefully review the safety recommendations for tools and equipment, and consider personal protection for respiratory safety and ventilation in your work area. Starting with Part 2 of this series, a selection of decorative woodturning projects ranging from simple to more complex designs will be introduced. The projects cover segmented woodturnings using wood only, and also mixed-materials designs that incorporate semi-precious stones and minerals, synthetic materials, and jewelry-grade metals. Each project description includes information on materials, step-by-step instruction with actual photographs, and is intended to demonstrate particular designs and techniques. Feel free to mix or replace materials, and apply the techniques to your own designs.
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Part 3 Stepping up Your Game: A Contemporary Design.
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Calculations & Blueprints Center Line
2 1
2 - Second Layer (Top Ring) 1 - First Layer (Center Pattern)
B
B - Bottom (Block)
Bottom (Block): Single Block, Diameter = 8.0”; Height = 0.75” First Layer: diameter = 8.125”; n = 32; L1 = 1.06”; L2 = 0.53”; Width = 1.125”; Height = 1.25”; MA = 5.625 degree Second Layer: diameter = 8.125”; n = 20; L = 1.27”; Width = 1.125”; Height = 0.75”; MA = 9.0 degree Although this design appears more complex at first, only three layers (”rings”) are needed, similarly as for the project described in Part 2 of this series. The Bottom layer is made from a single piece of material, and no individual segments will be needed. Later on, and when using more complex or larger designs, a segmented bottom layer may be warranted. The First Layer (Center Pattern) is actually made by combining 16 segments, made of three individual layers, with another 16 segments, composed of 5 individual layers. However, we will be using pre-glued (laminated) boards before cutting each set (2 x 16) of segments. 10
The Second Layer (Top Ring) consists of a simple ring of the same material (20 segments). This project builds on the one that was introduced in Part 2, and also uses a similar – “prelaminated board” approach prior to cutting the segments. Two additional design elements are included in this project1: (i) The center ring design consists of two sets of segments with different length; (ii) We will use veneer to separate patterns in this design.
Veneer Layers (2x)
Board #2
Board #1
Veneer Layers (4x)
Σ (n) = 32 16x
16x
Veneer Layer (1x)
The general steps involved are mostly identical to the ones covered for the previous project described in Part 2 of this series: (1) The assembly consists of three layers, the bottom, the center ring design, and the top layer (ring); (2) All general steps involved in the assembly of the layers, and the bowl for turning, are the same as for the first project. 1
This general design has been used by Ray Allen in various projects, see Ref. [3] in the Literature section. 11
Center Ring Assembly There are no set rules of which ring or layer to start with, the order very much depends on your design. For smaller projects I recommend to (1) start with the center ring, (2) prepare the base next, and then (3) continue with the top layer(s). For each ring to be assembled, carry out the following (6) Steps. Note that this sequence is applicable to a large variety of projects, regardless of ring size or the number of segments. Recall that I recommended to select segment numbers that can be divided into quarters. The purpose of this will be shown in the following illustrations. (1) Start with gluing pairs (for a ring with 32 segments – 16 pairs); add a layer of veneer vertically between each segment; (2) Combine the pairs to obtain quarter rings (4 quarter rings, 8 seg ments ea.); continue adding veneer between the pairs; (3) Check for accuracy of the 90 degree quarter circle, and correct by sanding if needed. Note: You will need 32 pieces of 1/16” Yellowheart veneer, 1.92” (48.7 mm) in length. Cut them from strips that are 1.12” (28.6 mm) wide. A total of 69.7” (177.0 cm) will be needed. When assembling the segments, take note to use the alternating segment patterns. Check for the proper alignment of the center strips. After finishing the assembly of the center ring, check its final diameter before cutting the segments for the top ring. Slight changes may result due to the thickness of the veneer that was used. Make adjustments if needed, i.e. recalculate the segment length. 18
(1)
Begin with gluing pairs (for a ring with 32 segments – 16 pairs). Add one layer of veneer between each of the segments.
Continue with combining two pairs. Again, add one layer of veneer between each (1.5) of the pairs. With this step, you obtain eight pieces with four segments each.
(2)
Proceed with combining two pieces with four segments each to one quarter ring. Recall: for a ring with 32 segments, eight are needed to make up a quarter. Again, add one layer of veneer between each of the pieces. 19
Bowl Assembly Before starting with the assembly, prepare and cut the veneer segments that will be used for a total of four (”separating”) layers. Two will be placed between the center ring and the bowl bottom. The other two will be placed between the center ring, and the last (top) layer. The lighter colored layers (two, Yellowheart) are placed above and below the center ring, and the dark layers (two, Wenge) are located above the bowl bottom, and below the top ring. The segment dimensions for all veneer segments are the same as for the top ring (Table 1), using a height on 1/16” (1.59 mm). They can all be cut at the same time, using veneer strips of 1.125” (28.6 mm) in width, and a miter angle of 9.0 degree. We will need 20 segments per layer for each of the light, and the dark color, a total of 40 pieces of Yellowheart, and of Wenge veneer (1/16”; L = 1.31”). Approximately 63” (161 cm) of veneer strips, 1.125” (28.6 mm) wide are
Stop Block
Veneer Segments (40 x 1/16” Wenge, & 40 x 1/16”Yellowheart)
Miter Fence (9.0 degree)
Veneer Stock (Stripes of 1.125”)
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With the next steps, we will add the “separating” veneer layers to our design, starting at the bowl bottom. Rather than building rings from 1/16” veneer segments, we will add (glue) the segments directly onto the bowl bottom. Begin with the first (dark, Wenge) layer: First veneer layer (1/16” Wenge) Veneer Segments
Bowl bottom After completing the first layer, place the bottom upside down, add some weight, and leave for about 45 mins to cure. Note that the chuck is still attached. Next, re-attach the bowl bottom with the first veneer layer to the lathe. Remove the segment corners, outside, and inside, by turning. Slightly sand the veneer surface true and even by removing uneven sections, and excess 25
Re-attach the bowl onto the lathe, and slightly turn the top side flat and even. Only small corrections should be needed at this time. Finish by sanding the outer surface of the center ring true and even.
Lathe
Center Ring, Surface
Next, continue by adding the two veneer layers onto the top end of the center ring. Use the same steps as described earlier for adding the veneer layers onto the bowl bottom. Remember this time to start with the Heartfelt segments, and then follow with the Wedge veneer layer. As for the bowl bottom, add the veneer segments now directly onto the top of the center ring. Place the assembly upside down for about 30 muns after each layer is completed. Finish each layer with light sanding to assure the surface is true, and even. 28
Top Ring Assembly The top ring consists of 20 segments of the same material. Follow the basic steps (1) – (6) as outlined earlier for the center ring. Note that the number of segments will be 20, and 5 pieces will be needed to form a quarter ring. With the first step, 8 pairs need to be assembled, leaving 4 segments to prepare four sets with three segments thereafter. One pair of two segments, and one with three segments will then be combined to form a quarter ring. Stop Block
Segments (20 x) (Bird’s Eye Maple)
(1) Combine segments to pairs (8), then add one Segment to each of four pairs.
(3) Check quarters for 90 degree fit.
Miter Fence (9.0 Degree)
Stock Material (Board)
(2) Combine to form quarters (4 x).
(4) Combine quarters to halves (2x).
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(5) Check halves for 180 degree fit.
(6) Combine the halves and clamp securely.
After setting the top ring aside for at least 45 minutes, continue with the final step of stacking the top ring onto the bowl assembly.
Prepare the top ring for gluing by sanding one side flat and even (belt/disk sander). “Dry-fit� the top ring to ensure that the seam will be tight and closed all around. Add glue, and place the top ring as centered as possible onto the center assembly.
Center Ring Assembly with Two Layers of 1/16� Veneer.
Finished Top Ring, on Belt Sander.
The final Bowl Assembly.
Set aside (overnight) before turning the bowl.
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Turning Take the time to decide and turn the outside to the desired shape: The outer shape is the most important part for the final impression! Next, proceed with turning the upper (open) side of the bowl. Turn the opening to its intended width, then work your way back towards the head stock. When turning projects that are a bit larger, I recommend to start with the section farthest away from the chuck. This will give you a feeling on how stable your piece will be with respect to vibrations or a potential catch on your tools. The section that is the furthest away is the most sensitive part. Try to achieve a smooth transition at the top (rim) of the bowl, on the inside, and towards the bottom. Be careful not to turn too deeply into the bottom of the bowl. Once you satisfied with the outer shape, invert and re-clamp the bowl, using NOVA Cole flat jaws. I recommend to use the tail stock for additional support, and leave it on until the very last moments. You may chose to remove the recess at this time. But only do so once you are completely finished with turning, and sanding of the outer shape, and also the inside. Continue with finishing the bottom of the bowl.
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