Blaine Petersen: Turning Chess Pieces

Blaine does not play chess, but has become a devoted turner of chess sets to satisfy the requests of family members. It is obviously a labor of love requiring precision and care. He displayed a completed set at the recent Utah Symposium Instant Gallery.

Materials

The dark wood is highly figured bocote and the light wood is primavera (white mahogany). The dome on the queen piece is light holly and, on the black queen, holly dyed black.

The base of the chessboard is walnut with fiddleback makore (Africant cherry) veneer. The squares are highly figured bocote (dark squares) and birdseye maple (light ones). The border is by Sauers and Company, purchased from Woodcraft. The strip is white maple, dyed black, and mahogany item #250-016-2.

Design Issues

A number of issues must be considered before turning begins. First is the design of the individual pieces of a chess set. The turner has total freedom in the designs; however, tradition dictates that the king be the tallest piece in the set. The other pieces on the back row of the board should diminish in height as you move from the center of the board to the edges. Blaine provided a handout that included several references for designs and material sources. Another issue is the choice of woods to be used. A complete set traditionally involves a set of dark pieces and a set of light pieces. The woods must be sufficiently dense and close grained to hold the fine detail in the pieces. In this demo Blaine used Bocote for the dark set and Primavera (white mahogany) for the light set with a warning that Primavera does darken to a tan color as it ages.

Blaine also resorts to stains or dyes to generate color matches or contrasts for special elements or details of the pieces. He has learned to purchase initially enough materials, with allowance for waste and errors, from a single source to complete a set and maintain color and grain uniformity. The size of blanks to be used for the individual pieces is entirely dependent on the designs chosen.

The designs Blaine chose for his sets primarily involve basic shapes consisting of beads, flats, and coves, many of which are very fine and require special shop-made tools. Due to time limitations for the demo, Blaine demonstrated the techniques for creating the fine details and for creating the special features of the specialty pieces: the rook, queen, bishop, knight and king.

The Rook, or Castle

This piece is traditionally shaped like a castle tower topped with battlements. In addition to the basic beads and coves forming the tower, the special trick is carving the notches in the top of the piece to define the battlements. Blaine has, in the past, has cut the notches of the rook with the Dremel as described below and then, used a hand file to make them square.. However, he has developed a more elegant technique using a Dremel–type rotary carving tool with a 3/16" straight bit.

He first mounts the partially completed piece (completed except for parting off from the base) in a scroll chuck. He marks a very fine pencil line 3/16" from the top edge of the castle as a depth reference. He carefully tapes the Dremel-type tool to the concave side of a Robust tool rest so the axis of the tool is parallel to the edge of the tool rest. With a 3/16" cylindrical bit mounted in the tool, Blaine adjusts the tool rest and banjo so the bit is perpendicular to the axis of the lathe and the banjo is perpendicular to the ways of the lathe. He then locks the lathe spindle using the indexing features of the lathe and carefully advances the rotating bit into the wood by sliding the entire banjo directly toward the headstock until the leading edge of the bit just touches the depth line. He then retracts the banjo and stops the rotary tool.

The spindle is then rotated to the next indexing position and locked. In this case, Blaine creates six notches so he used the "A" hole on the headstock and the 1, 3, 5, 7, 9 and 11 positions (60° apart) of the 12 indexing holes in the spindle of the Powermatic lathe. The banjo is again advanced to cut the second notch. The process is repeated until all six notches are cut. The rotary tool will usually leave some burn or burnish marks in the notches. Blaine removes these by wrapping a strip of fine-grit sandpaper around the shaft of a scratch awl and carefully sanding the interior edges of the notches. With the notches completed, Blaine sands the piece with the lathe turning to remove any burrs from the exterior and to create the final surface finish before parting off the finished piece from the base. Blaine prefers the Nick Cook thin parting tool (by Robert Sorby) which has a fluted edge. The corners of the flute provide a cleaner parting cut than square edge tools. He strives for a dead flat parting cut. The base of the finished piece is then hand sanded on a sheet of sandpaper laid on a flat, hard surface such as the lathe bed.

The Queen

The queen is also a notched piece although the notches around her crown are shallower than those of the rook. This process uses a 1/8" straight bit to create 8 notches 45° apart. They are formed in the same way as those of the rook. In addition to the notches, the crown is embellished with a small domed inlay inserted into the top of the crown. The inlay is a partial bead formed on a small tenon that can be inserted into a hole drilled in the top of the crown. This inlay can be made from a small piece of contrasting or dyed wood.

The Bishop

This piece can be turned on axis in one mounting. Before parting off from the base a saw notch is to be created to suggest the bishop’s miter. Blaine does this while the piece is in the chuck and the spindle locked. He has created an L-shaped jig. The base of the L is clamped to the bed of the lathe. The wide horizontal top of the leg of the L is beveled 30° from the horizontal. A notch was cut in the center of the top edge of the jig to allow the jig to surround the bottom of the bishop’s head. The length of the leg of the L is set so that the bevel just intersects the upper edge of the bishop’s head at the point where the saw notch is to begin. Using a fine-tooth dovetail saw laid flat on the jig bevel Blaine carefully saws a notch 1/8" deep into the bishop’s head to define the miter. He then lightly sands the piece with 400 grit paper to remove saw burrs. The piece is then parted off from the chuck with the narrow parting tool and base sanded as before.

The Knight

In Blaine's process the horse-shaped knight is carved rather than turned. He begins with a rectangular blank with square cross-section. On a band saw he precuts the blank to remove the side sections of the upper part of the blank to form an inverted T. The stem of the T is left ¾" thick and long enough to suit the length of the horse head pattern. The flat of the T is left thick enough to be gripped firmly and squarely in a four-jaw chuck and to provide a stable surface for subsequent band saw cuts. It is helpful to make a shallow undercut at the intersection of the stem and the flat of the T. It is important that the portion of the blank other than the stem of the T be left square and flat. The blank is then mounted in a four jaw chuck and a pin is turned with a parting tool at the intersection of the stem and flat of the T. This pin will be the tenon by which the carved head will be mounted to a turned base. Blaine pastes a paper pattern of the horse head profile to the broad side of the stem of the T.

A band saw or jigsaw can then be used to cut around the pattern to form the profile of the horse head. Blaine then marks the centerline of the thickness of the head with a pencil. He uses a small belt sander to shape the thickness profile of the head to be symmetrical on each side of the center line. Blaine uses a rotary carving tool to round and define the shape and details of the horse head. To form the eyes in the head he uses a small (1/16") serrated circular leather-working tool. The head is then parted from the rest of the blank and hand sanded to finish. The base of the knight is turned separately either from the remainder of the rectangular blank or another piece. It is drilled with a hole to receive the pin or tenon at the bottom of the head. The base can be sanded on the lathe and parted off and base sanded as before.

The King

In the design Blaine used the king is characterized with a formee cross (like German iron cross) that tops the crown. To form the cross Blaine turns a ½" diameter dowel. He then forms a clean but tiny full bead at the free end of the dowel ensuring that the face below the bead is cut very clean. He uses the Cook parting tool to create a cylinder ½" long (equal to the diameter) beneath the bead and leaving a stem about ¼" in diameter below the cylinder. This stem will become the pin that will join the finished cross to the crown of the king. Blaine uses a pyramid (point) tool applied at the very edges of the ½" cylinder to create both the upper and lower V notches that define the four legs of the cross. It is important that the depths and angles of the sides of those notches be equal so the legs of the cross will be perfectly balanced and symmetrical. With the notches formed the stem can be refined to 3/16" to fit into the hole that will be drilled in the crown. Blaine uses the small belt sander to sand both sides of the cross to be flat and rectangular in thickness cross section. The thickness of the cross should be the same as the diameter of the pin (3/16").

Forming Beads and Coves

The beads and coves that embellish the basic pieces in Blaine’s design are very small (1/6" – 1/8"). Blaine has created some special tools to facilitate turning these small details. For the coves he has taken drill rod of various diameters ranging from 3/32" to ¼" and ground the tips at a flat 45° angle. These tools can be held in a handle similar to the keyed or keyless Handy Chuck. When applied point-down to a spinning piece the curved cutting edge produces a nice cove. Blaine uses bead forming tools such as those manufactured by Ashley Isles and Henry Taylor in sizes from 1/16" to ¼" for cutting his smaller beads conveniently and quickly. For larger beads at the base of pieces he uses the Easy Beader tool by Robert Sorby. Another tool Blaine has modified to clean up tight areas is the pyramid point tool. He has ground off one face of the pyramid to provide a flat rather than sloped face. This provides more clearance for getting into tight corners.

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Demo illustrations...

Show and tell

Wood exchange and drawing

Turner's gallery