07-26-2010 05:35 PM
I hope someone here can help me. I'm trying to build an old fashioned A&W root beer stand for my neighbors car club for a show in March. I can't seem to figure out the formula for cutting a correct barrel stave. We're making it out of thick cardboard as it is only temporary.
The total heighth of the assembly will be nine feet tall, done in three sections. Is there a formula for a cutting a curved board with a taper?
Thanks everyone! Bob
07-27-2010 05:10 AM
You need to determine the top/bottom circumference and the middle circumference of the barrel. The sides of each stave are curved (not tapered) to achieve the belly of the barrel. After deciding the middle circumference, divide that number by 36 (or whatever number that you want/need) to determine the width of each stave. Divide the top/bottom circumference by 36 to get the width of each stave at the ends. Draw an arc from the middle width to the end width and remove half of the difference (middle width minus end width) from each side of the stave (both ends).
To find the angle for the curved joints, divide 360 degrees by the number of staves (360 / 36 = 10) and make half of that angle on the edge of each stave (5 degrees using my numbers).
I hope this helps...for mor more information, Google "making barrel staves".
07-27-2010 09:14 AM
Good luck on your cooperage. I was at the St. James Gate Brewery (Guinness, Dublin, Ireland) and they had a great video on their coopers making the staves. Yes it's a pretty complex process, but I bet with a curved template and a chamfer bit on the router you could do a respectable job. Maybe a 15 degree bit up against the curved template for each stave. What are you using for rings? The process for getting the first 2 rings on is pretty simple, it gets a little tougher for the bottom 1 or 2 (depending on total number) where you ahve to pull the taper back together. Should be exciting, post some pictures.