"360 degrees to a circle.
for a simple drum 8 staves will work. Divide 360 by 16 if you want to dress both sides or 8 if you only angle one side.
Angle on the staves is 22.5 degrees when planing or cutting both sides or 45 degrees if planning or cutting one side.
The nice thing about 8 staves and one side cuts - Cheap plastic miter boxes are set to 45 degrees - no guessing, no messing and it works.
Sand the section where the natural 90 degree is glued to the 45 degree and you have an octogon hoop.
I've made these with 1/4 by 4 x 2 foot alder. you can make one drum with 8, 3 inch sections.
Home Depot is selling thier Alder at this size for $1 close out until they are gone.
So the basic math is
if doing both sides of the staves
# of staves / 360 = angle of cut
example
360 / (8 staves x 2 sides) = 22.5 degrees
360 / (16 staves x 2 sides) = 11.25 degrees
If doing one side (works for me)
360 / 8 staves = 45 degrees
360 / 16 staves = 22.5 degrees
360 / 12 staves = 30 degrees
OK now how big around is this drum going to be?
Diameter wanted x pi / number of staves = length of each stave
example
I want a drum that's 10 inches across.
10 x 3.14 / 8 staves = 3.925 inches
What about the 3 inch drum I built from one piece of 1/4 x 4 x 24?
Turn it around
length of stave x number of staves / pi = diameter
3 inches x 8 / 3.14 = 7.64
Now the drum is octagon so it's not 7.64 at the points or the flats, but this is close.
If you use 1 inch thick boards, then you can sand it down to pretty much round on 8 staves.
I may have made an error in my calculations, but you get the idea - I'll try to remember to take a picture of one of the drums this weekend."
Here's another shot of the one I made using Legba's method of calculating the angles and over-all size of the frame. Thanks again Legba!!
