Many years ago I bought me a book, called “Woodturning Wizardry”, written by David Springed. I was fascinated by the things he created, but I never really tried out this kind of turning.

From time to time it popped up in my mind to do give it a try, but it stayed with only one experience, in the form of a box with latticed lid. (See picture)

There is nothing wrong getting inspired by other artist, but the goal should be to create your own style and your own objects.
Inspired by the things David Springed makes, (for example, a cube in a sphere) I played with the idea of making a sphere in a cube, turned from a solid piece of wood.
Struggling with this idea for a while and thinking about how to realize this, I went on to my lathe and just had a go. I started with a piece of ash, planed/sawed and sanded it to an exact measurement of 85 mm. all sides. This first attempt was really trial and error, some simple drawings were made on the workbench and from an old file I grinded a special tool, but all went very well. I didn’t manage to get the sphere completely free by turning, in the 8 most outer corners, the sphere was still held by little triangles of wood witch couldn’t be reached with my standard tools. These triangles were cut with a small recipro saw blade, held in a Stanley knife-holder. Sanding the sphere was a bit tricky, but not difficult.

My first attempt of a sphere in a cube.

 Being surprised how easy all went, I developed this idea further and made another cube to try it again, but this time giving more attention to the sequence of workflow and preparing some tools. Also I would try to hollow the sphere to create a little bottle in a cube.

My second attempt, a bottle in a cube, made in Yew and Grenadille.

 

In the following story, I will explain how I made this Bottle in a Cube. 

• Select a dry and medium to fine grained piece of wood, for my first trial I used Ash and for this project I
  used a piece of Cherry.

• Saw, plane and sand it to an exact cube, I made mine 85 mm. each side, but it can be any size.

• You will need a special tool for cutting the corners between cube and sphere, so make a real size drawing of the cube and draw in a circle of  79 mm. , the diameter of the sphere will be 6 mm. smaller as is the outside of the cube.

• This tool is an undercutting tool; it cuts through the corners, which are left when turning the windows, and parting of the sphere.
  Only the front tip and left side of this tool are cutting, the curved side of this tool is smoothed of and polished, to let the curvature of the tool follow the circumference of the sphere.

• One other devise needed is a template to measure the width of the window and the curvature of the sphere, this can be made of some stiff cardboard.

	Real size drawing with undercutting tool.
	A sample cut in halve, to show the undercutting action.
	The template measures the dept and the curvature.
	On the picture, from left to right: the Cherry cube, a earlier attempt from Yew, a finished bottle from Walnut/Beech, real scale  drawing with template and the curved undercutting tool with grinding template.

 

How to make the curved undercutting tool?? 

Turn a disc from scrap wood, with the same diameter as the sphere, in this case 79 mm. and use it as a template to grind the curvature on the tool.
Make the curved edge dull and polish it, only the front tip and left side edge doing the cutting.
The curved and polished side will ride against the just turned curvature of the sphere.

To hold the cube securely in the chuck, I made some wooden jaws, which were mounted on my Axtminster 4-jaw chuck.

 

Picture: 1   Start preparing a cube and sanding it to an exact squarnesh and measurements of 85 mm. all sides.

The cube could be hold in the outer jaws from the four jaw chuck, but in the final turning actions, where the sides of the cube are slightly turned inwards, it can’t be gripped concentric anymore.

To hold the cube securely, there has to be made a wooden chuck.

This is how I made my wooden chuck.

Picture-2   The wooden chuck is made from 40 mm. thick plywood. A disc is cut on the band saw and quarter sawn.

Picture-3   The wood plate jaws are screwed to the plywood parts. Be alert to align the jaws in the right direction, it is very easy to make mistakes when the jaws are of the chuck.

Picture-4   Because the chuck exists of 4 separate parts and to make sure, the wooden jaws won’t move during turning, I tightened the chuck by gripping a wooden dowel.

Picture-5   The wood plates trued up and the corners rounded over.

Picture-6   Two circles are described, the outer circle meets the corners of the cube, and the inner circle meets the sides of the cube.

Picture-7   Place the cube exactly on the described circles and draw lines along the sides of the cube.

Picture-8   The square form has now to be removed, about 20 mm. Deep.

Picture-9   First, turn a 20 mm. recess, just touching the inner circle.

Picture-10   Then, the remaining corners are sawn and chiseled away.

 

The working sequence of making a Bottle in a Cube.

 

Picture-11   Wooden chuck ready and the cube gripped securely.

Picture-12   Start with the first window in a side grain side of the cube. Mark the center with the point of the skew, set the compass to 30 mm. place the right foot of the compass in the center and mark the width of the window with the other foot of the compass.

Picture-13   The diameter of the sphere is made 6 mm. smaller as the outside of the cube, so in each side I started with a recess from 3 mm. deep, to define the diameter of the sphere.

Picture-14   Measuring the dept with a dept gauge.

Picture-15   Start hollowing the window with a 6 mm. spindle gouge, and forming the curvature of the sphere.

Picture-16   Checking the width of the window and curvature with the template. Refine the curvature and check it with the template until the right dept is reached.

Picture-17   Place the undercutting tool and let it ride against the curvature of the sphere. Push the tool forward and let it follow the curvature.

Picture-31   The bottom window cut, and viola, the hollowed sphere free in its jacket.

Picture-32   Turning a dowel, which fits exactly trough the hole and pushes the bottom and the rim simultaneously.

Picture-33    The setup for sanding the sphere.  I don’t bother the indention made by the revolving center, because the bottom will be plugged and you will never see it.

Picture-34   One hand is holding the cube, and the other is sanding the sphere trough the side, top and bottom windows of the cube. It is a little bit tricky, but not very difficult to do. Go through the grids from 120 to 400 and don’t skip any grid.

Picture-35   To give the cube a more pleasant look, I turned the top and sides slightly inwards. Therefore, push the sphere back to give clearance at the front and secure it with some folded sanding strips.

Picture-36   Carefully turn the sides slightly inwards. With a 6 mm. shallow spindle gouge, cut from the most outer corners towards the centre. Be careful when starting on the corners, because there is more air then wood to cut.

Picture-37   One side finished.

Picture-38   Sand the surface, but only the visible solid wood. The corners, which are seen as a ghost image, are sanded with the lathe off.

Picture-39   When all sides are done, I made a plug in the bottom, sanded the whole piece further by hand and buffed it with a buffing wheel, using white diamond. Be careful not to touch the upper corner of the cube or the buffing wheel will grap it.

Picture-40   And the hollowed sphere in the cube is ready.

Picture-41   Making the neck for the vase. Take a suitable piece of wood, Beech in this case, and grip it in the chuck. Here I’m using O’Donnell jaws.

Picture-42   Drilling a hole all the way trough.

Picture-43   Centering the piece and turned to a cylinder.

Picture-44 Grip the neck with the tennon in the chuck to form the spout.

Picture-45   Turn it over and fit the spout in a piece scrap wood and forming the bottom end of the neck.

Picture-46   I used a piece of ebony for the transition between bottle and neck.

Picture-47   I gave this piece two coats of finishing oil and buffed it with a rotary brush when dry. This is quite save, because this kind of brush doesn't grip.

Picture-48   The finished piece: Bottle in a Cube.

Picture-49   The tools used for this project.