FOOTBAG PATTERNS

by Derrick Fogle

[Ed. Note: See also http://www.footbag.org/footbags/patterns/ (the Footbag Patterns page).]

The specific design of the `shell' of a footbag is, from my understanding, what makes different kinds of footbags patentable. Making flat pieces of material join together into spherical shapes is no easy task. The problem is that for any flat piece, there has to be some extra material left in it to compensate for the `bulge' once it is turned into a part of a sphere. While attempting to generate templates for footbag patterns on my computer, I found out that this `spherical compensation' is essentially an unsolvable mathematical problem.

No matter what, footbag design and construction have to rely on both good patterns and good construction. Spherical compensation is critical on 4-panel and 6-panel footbags. The gray area starts around 8 panels. I round the edges of my templates to compensate for the spherical bulge for everything up to 12 panels, but that is because I have a very anal-retentive sewing technique that requires very exact panels. Once you get beyond 12 panels, however, it really doesn't matter.

The Basic Pattern

All footbag patterns have their basis in an "equidistant" division of a sphere's surface. This "grandmother" of designs spawns three primary categories of division. These are the "whatever it takes to make it fit" divisions like the 2-panel Hacky Sack (TM) design and the 4-panel Mumbus (TM) (TM) design; the basic "citrus wedge" division made by dividing the surface of a footbag the same way an orange creates it's own slices; and the geometric equidistant division where the footbag surface is divided into equal plates whose centers radiate from the core of the sphere in an evenly spaced geometric pattern. Pretty much all of the patterns that exist contain elements of all the basic designs, and the more complex the patterns get the less distinct the differences are.

Modification Techniques

There is one primary modification technique that is the basis for all variations in patterns: Subdividing and Rejoining. By taking an existing pattern, and breaking a panel up into more smaller panels you create new designs. You can also join panels where there was previously a seam, creating other new designs.

Of course, to get some designs, you really have to stretch the concept of subdivide/rejoin. The primary `exception' is asymmetrical modification of panel outlines. If you broke a spherical surface into enough little tiny pieces, and rejoined them to the point of having a few large panels, you can get pretty much anything, including the classic two-panel baseball-style Hacky Sack (TM) pattern.

But a simpler way to look at the 2-panel Hacky Sack (TM) design is asymmetrically modifying then rejoining a 4-panel, equidistant pyramid design. Round out each of the triangles involved, leaving a little `tail' on one side of each panel, then join each of two sets of panels by the tail, with each new panel inverted on the other. Of course, you can also create the classic two-panel by modifying a 4-panel citrus-wedge: Flatten the tops of two opposing panels, and widen their bottoms; and invert that procedure for the other two panels. Then join each pair of opposing panels where their new wide bottoms join.

To further muddy the lines between pattern types, consider that a 6-panel footbag is both a perfect equidistant pattern and a modified 3-panel citrus wedge. The 8-panel design is a perfect equidistant and a subdivided 4-panel citrus wedge. The primary distinction that warrants a category all it's own for geometric equidistants is that the number of panels is directly related to 3-D geometrical progressions: The 4-, 6-, 8-, and 12-panel designs are examples. There are more geometric equidistants out there, but I have yet to see the practical application of them.

Ice-Cold Patterns

There is one interesting phenomenon in equidistant footbag pattern design that I have stumbled across, but I can only note it, not explain it. There are 720 missing degrees in a footbag. Always (almost). Take a 4-panel. Three panels meet; if it were a straight-walled pyramid, the angle of each panel corner is 60°ree;. With 3 panels per joint, that's a total of 180°ree;, or 180°ree; shy of 360°ree;. With a total of 4 joints (I'll let you decide if this is a high principle), the total number of degrees the footbag lacks is 720. Now take a 12 panel:

3 panels per joint at 108 degrees each:     324 degrees
                                          - 360 degrees
                                          =  32 degrees

There are 20 joints in a 12-panel          (*20)
Equals the magical....                      720 degrees

This principle holds true for every geometric footbag I have ever tested. Wow, my brain is going to melt.

More Complex Patterns

Once you get past the philosophical task of trying to decide which category a design most resembles, you can begin to apply the technique of subdivide/rejoin to come up with all sorts of wonderful patterns. A few neat examples are: the 30-panel, made by dividing each pentagon of a 12-panel into 5 triangles, and then joining each triangle where there was originally a seam; you can also get the Juice (TM) 32-panel pattern by clipping the tips off each pentagon in a 12-panel and turning those little tips into one panel, then shrinking/enlarging the resulting panels; a 14-panel I-DIG (TM) (licensed from FC's Tangent) is made the same way from a 6-panel.

There is really no limit to what you can do with the subdivide/rejoin principle. Witness the 100+ panel footbags the Danes create; they do alot of division and not alot of rejoining. Of course, notoriety awaits those who come up with really creative ways to do this. The Twisted (TM) footbag is a wonderful example of a uniquely subdivided/rejoined 4-panel geo-equi design. That most unique footbag pattern innovation in years was born by cutting up the original triangles of the design into spirals in a way that allowed those spirals to become the three arms of a new panel when joined where there was originally a 3-way panel joint.

Endless opportunities await the creative who want to make new patterns. There's a woman in KC somewhere that occasionally makes a spiral 2-panel design. I'm still waiting to see someone that takes the Twisted (TM) design concept to a 6-, 8-, or even 12-panel footbag. I've also seen some very intricate interlocking-star patterns from a woman in the eastern US named Anna Foot (not sure of spelling).

Other Design Ideas

For those who hunger for something a little more radical, I suggest the "garbage bag" technique. Get a wooden or styrofoam ball about the size of a footbag. Use small pieces of pliable tape (duct tape is recommended) to completely cover the ball. Now, using an exacto and some imagination, carve up that ball into some totally asymmetrical panel pieces. I recommend using at least 8 or more panels and avoiding "innie" angles, because then you must peel off the tape and flatten them out, trace them, and use the trace for panel templates. Using too few panels in a design almost assures that the flattening/tracing process will not render panels that go back together well. Remember to add a little extra for the seams when you create the panel templates. Numbering your panels and putting your prototype back together will help, too. Danny Judd is the first person I know of to have toyed with this idea, but I have yet to see anyone follow through and create a cool design.

Another idea that could actually be a terrific marketing idea is to take a basic footbag design and insert some simple logo-based panel into it. Someone would have to come up with the capital to license the logo, but Randy Denham came up with the idea of putting a Chief's Football `Arrowhead' logo into a basic 8-panel bag, simply cutting the logo pattern out of the original so that it substitutes for one of the 4-way panel joints (using certain color schemes, of course). Think whether those might sell during football season, eh?

It might be difficult to improve on the other really different design idea. The Sipa Sipa (TM) crocheted footbag could be viewed as a spiraling series of little-bitty panels, but that description falls short of giving full credit to the seamless, panel-less uniformity of simply weaving the shell out of yarn. But anything is possible. One idea Jeff Haas worked on for awhile was a multi-body crocheted footbag. He made small citrus-wedge shaped bags and then sewed the tips of them together in 4-, 6-, and 8-panel configurations. You could poke your finger right through the middle of the bag and no beads would fall out.

If you've ever considered designing footbags, what the heck, give it a try! If you make them, maybe you can inspire yourself to do something a little bit different. Of course, I'm not going over the actual sewing together of a footbag here, but that's been done before. Maybe I'll do that next issue.

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