PROTOSHAPER©
- a description by the author - Jim Staley
Protoshaper© is a
spreadsheet for Microsoft Excel. It helps folks understand how to make bowls
and vases other than the standard straight-sided Ring Master bowl.
If you
admire the photos of the curved bowls that are shown on the Internet, but don’t
know how to make them, then this software is for you.
The first spreadsheet
graphically explains how and why only one angle for any combination of board
thickness and ring width can make a Ringmaster bowl.
What happens and why when
you have either larger or smaller angles is explained graphically, also.
The next spreadsheets use the concept of
prototype shapes. I noticed that virtually all of the large variety of shapes
that I found could be classified into a few basic shapes:
- Standard Ringmaster Bowl: These have straight
sides. The angle is determined by the thickness of the board and the wall
thickness.
- Simple Vase: This is simply one standard shape
overturned on another. A ring with vertical sides may separate the two.
- Curved Bowl: The sides after sanding are curved
outward rather than straight. The angle of each ring progressively increases.
This gives a shape that many find more pleasing to the eye than the
straight-sided standard Ringmaster bowl..
- Barrel: This is one Convex Curve bowl overturned on
another. A ring with vertical sides may separate the two.
- Horn: The sides are curved inward. This gives an
appearance that many find to be more graceful. The angle of each ring
progressively decreases.
- Round: The sides of the bowl form the arc of a
circle when sanded. The angles of the rings are fixed.
- Chalice: This vase in its simplest form is the
bottoms of two horns joined together. Instead of a horn, one or both of the
horns can be replaced by a curved bowl.
- Long-necked Vase: The rounded body is capped by a
straight-sided neck with a lip.
- The user starts with the Protoshape,
then modifies it by inputting board thickness, wall thickness, and diameter of
the largest ring.
For all but the standard Ringmaster Protoshapes, the user
modifies the angles.
- Protoshaper© outputs the outer
diameters (OD) and inner diameters (ID) of each ring and the diameters of the
remaining blank.
- It also outputs the setting for the Precision Angle Guide.
- This tool is probably indispensable for making complex shapes and is useful for
making any shape.
- For those cases where more than one board is required,
Protoshaper© calculates the number of rings required and
specifies what ring should be cut from what board.
- For particularly complex
designs, the user may have to consult the table that gives blank dimensions and
ring dimensions to insure that the ring can be cut from the designated board.
- By changing the diameter of the largest ring and the angles the user can create
an almost limitless number of designs.
- Effects of any inputs are seen
immediately on a diagram of the cross-section of the shape.
In the event that modifying standard Protoshapes does not give the desired shape, a Free Form spreadsheet is
included:
- After entering board thickness and wall thickness, the designer
enters diameters of the desired shape.
- These diameters may be obtained by
measuring an existing bowl or vase, or they may be purely from the imagination
of the designer.
- The design may be up to 11 layers.
You
will need to have Excel
®
installed on your computer to run this spreadsheet.
Excel®
is a registered trademark of Microsoft Corp.
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