Jim's Bol is 8 feet wide. It is all made from triangles.

The Plans are available on page 34 & 35 of the Fall 2002 issue of
KITING magazine, Volume 24, Issue 3. Or here: Warning! It takes a while
to download on a dial-up (phone) connection.

http://www.geocities.com/gengvall/2003/BolPlanGE.doc

There is a file available on the CTKiters Yahoo Group available
for download that will make planning your own version of the Bol much
easier. Click here:

http://groups.yahoo.com/group/CTKiters/files/2003 Kitemaking Workshop/bol.doc

If you have any trouble getting to the File in the CTKiters Yahoo location, here is another link to the file. If you can look at this page and have Word on your computer, you should be able to see this file: http://www.geocities.com/gengvall/2003/bol_rwb.doc

Back to Workshop Projects List: http://www.geocities.com/gengvall/2003/projects.html

Bol Math: When Jim Johannesen designed the triangle Bol, he wanted an 8 foot diameter Bol. He took 8 feet, mulitplied by pi to get a 301.584 inch circumference. Divide that by the 15 hexagon triangles that rim the Bol, and it comes out to 20.1056 inches. Add a seam allowance, and call it 20.25 inches.

Only one problem: 20.25" works great cutting pieces from scrap. It either fits, or it doesn't. Cutting pieces from rolls of fabric, it's a different story. 20.25 inches turns out to be 3/4 of an inch too long to get 3 even triangles out of 60" fabric.

I always try to buy 60" fabric since it is the cheapest per square inch. Workshop Bol Kits will be cut using 20" base triangles. (20x3=60) This yields 5 triangles per row with minimal waste.

Triangles for hexagons will be 20" on every side. They are perhaps easiest to make using a compass using a 20" radius. A compass could be easily made from a strip of posterboard.

Triangles for pentagons will have a 20" base. Form the other two sides by measuring out 10" each way from the center, and use 54 degrees for the angle. Confirm by checking the top angle where the equal sides join is 72 degrees. (360/5=72)(180-72=108)(108/2=54)(54+54+72=180)

From 54 inch fabric, use 18" for the base of the triangles. Hexagon triangles will be 18" on every side. Pentagon triangles will have a base of 18", form the other two sides by measuring out along the base 9" each way from center, use 54 degrees for that angle. Confirm by checking the top angle is 72 degrees.

41" fabric, you do the math. (I'd use 13-1/2" for a base . . .)

Back to Workshop Projects List: http://www.geocities.com/gengvall/2003/projects.html