This sequence of images and text will follow the process that I use to make ceremonial wood rattles.

 

It begins with the selection of the birch wood blocks.  I try to avoid wood with weak areas as the shell will be thin and grain weakness will likely result in structural failure somewhere along the way.  Still, some grain patterning and even the beginning of spalting will make the finished sphere much more interesting.

I will look for wood that is at least 2.5 inches thick if I am hollowing wood across the grain as opposed to end grain hollowing.  I will cut perfect square pieces, and will try to place the grain centre to the centre of the cut piece if the end grain is important to the finished appearance.

After finding the centre by drawing two diagonal lines from the four corners, I will bore out a shallow hole with a 2.5 inch forstner bit so that I have a simple hole for the chuck to hold the piece for its shaping.

Once the centre is established by the bored hole, I will use a compass and pencil to scribe the largest circle that is possible from that block, and will use the same radius setting to scribe the second block that will be the match to the first.  If making more rattles at the same time I will pair up wood pieces that seem to have grains that mate well.  Once scribed, the block is cut to a circular shape on a band saw to reduce the work required on the lathe. (However, at times I have done the rounding on the lathe itself when I am doing smaller blocks.)   With a large shaping bowl gouge it can go rather quickly as long as the shaping is done from the flat face of the block, working toward the edges as the bowl shape is created.

I will first turn a 0.5 inch deep "base" with a diameter just large enough to be held firmly by the chuck in its narrowest setting.  Then I will shape the bowl, creating as closely as I can , a hemisphere with the largest diameter just below the face which has the bored hole being held by the chuck.  I will do this to both blank / blocks trying to ensure that they are of the same finished diameter and as similar a shape as possible without actually doing measurements along the way.  I do not do final rounding or sanding until later in the process.

I have found it most useful to establish the exact centre of the base with a small dimple.  Later in the process that enables the insertion of the point of the tailpiece at the exact centre as the sanding and initial turning is done to the sphere and later to the rattle with its attached handle.

I replace the piece on the lathe with the newly turned base in the chuck and then fashion the edge and hollow the hemisphere to approximately 1/8 inch thickness.  The staggered flange will add to the gluing surface and will enable precise alignment when the other half is turned.

The image to the right is the second half of the sphere with a matching flange.  I use a sharp parting tool to precisely cut the matching flange and test it till it is a snug fit, and then finish the hollowing process of this second half.

When both halves are turned and fitted, I add glue to the flange surface and press the two halves together and then compress the joint with a clamp until the glue is well set and hardened.  I do not worry about the glue squeezing out as it will be easily turned off later.  There will be little or no glue squeeze-out to the inside because I applied the glue to the first of the two haves turned and not the second.  If you are thinking to yourself : "He forgot to put in the pebbles / steel balls", do not worry.  I will add them later in a very easy manner.  In the past I used to add them at this point and then had to be careful that the glue would not get stuck to the rattle materials.

 When the hollow sphere has been properly cured (you do not want the glue to give way), I used a 1 inch forstner bit and set a caliper to the same diameter.

Using a 8 X 1.5 X 1.5 inch blank mounted in the lathe chuck, i turrned the handle creating one end as a 1 inch diameter insertion point.  I did a partial  cut off with a paring tool but leave the end piece attached till later.  It will need to be re-inserted in the lathe later.

 I take the hollowed sphere and bore a 1 inch hole exactly in the centre of one end.  This is where the small dimple assists in an exact centering of the drill bit.

 I select pebbles and two sizes of steel ball bearing for the rattle contents.  The stones make a harder thump sound and the ball bearings will chatter more and also roll around the inside of the rattle giving a residual sound that the stones alone are not able to provide.  These can be easily added to the sphere at this stage and then the turned handle is glued,  inserted and then clamped for drying

 Once the handle  and rattle glue joint is properly dry the handle and sphere are remounted on the lathe.  Here again the dimple put into the end face will assist in exact centering of the piece into the tailpiece of the lathe.  When this is mounted the trimming and sanding process can proceed.

 First I trimmed down the joint between the handle and the sphere.  In this manner the wood of the sphere becomes part of the handle and adds to the strength.  Shock or resistance is able to be absorbed by the thicker and stronger wood and not the thin portion of the sphere.  Then I trim the end at the tailpiece leaving the final 1/8 inch to be sanded down after it is removed from the lathe.  The rattle can be further trimmed if needed and sanded down with progressively finer grades of sand paper until the desired finish is obtained.  I ususally go through an 80 / 100 / 120 / 220 grit sequence and then burnish the wood with a hand full of birch shavings that earlier came from the same project.  Held against the turning  rattle a nice smooth finish is achived.

The finished rattle just prior to removal from the lathe.

Because I add a leather thong loop at the end of the handle I bore holes through the end and in from the bottom.  That way I can have the loop come out of the very end of the handle.

After this it can be waxed, varnished, lacquered, painted, decorated etc as desired.  The construction is finished.

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