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Discussion Starter #1
I have been working (not too successfully) on ideas for developing a router technique for making the barrel staves.
My goal is to be able to produce barrels of speciific size with repeatable accuracy.

Barral staves are tapered and angled along the edges where they join. I believe the taper describes an arc also. This would mean that the stave is widest in the middle with gentle curving tapers running off to each end with the edges angled.
The result, when assembled, is a rounded, double ended, conical shape tapering to the top and bottom of the barrel.

The old school method is to do this by hand with draw knives and specialty planes. I 'd like to figure a way to do it with a rounter and jigs.
So far I'm stumped. The elegant geometry of a barrel stave is defying me.

Any one ever accomplish this have any resources or info?
 

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I *think*... which is usually my FIRST sign of trouble... that the angle on the side of a stave will be the same even though the stave WIDTH is greater in the middle. The reason I think this is because you have a set number of degrees in a circle. The staves are basically forming a circle. The staves being wider in the middle will give you that barrel shape, but whether you're in the middle of the barrel or close to the top (or bottom) there's still the same number of degrees in a circle.

I haven't done a barrel myself. So I'm guessing. But this sounds right to me. :)
 

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Cliff

This is what I would try.
1st make a pattern(s) then make a template out of plywood and use it on the table router to make the staves all the same size. (with a Flush Trim Bit)
Then use a Chamfer Bit on both sides of the stave.(on the table router)
Then use a Round Nose bit on both ends of the stave. in a jig to keep it sq. with the end. (to hold the base and the top in place) a round dado slot on the ends about 1/2" from the ends.
Then use a Bull Nose bit on the side of the top and bottom to forum a socket to hold the staves in place.

Then put the stock in water or steam for a hour or two just b/4 you go to make the barrel.

I have made a buckets this way and it works but I don't use the water/steam because I didn't need to bend the ends in like you will need to do on the barrel.

I would start with the bottom and the put the metal band on to hold the base in place then with a band strap clamp pull the top of the staves in to the top plate then slip the top band on. (with a hammer ) at that point it should 90 % done then slip on the center band.

Hope this helps,Please post a picture or two when you get done with them.

http://www.sommerfeldtools.com for the bits, this is just one of many on the net.

Bj :)
 

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The only way you will get the accuracy you need is using a template. You will also need somebody to design the stave using Catia or a similar program. This should give you a consistant outside shape. One edge of the stave is straight and has no bevel. The other edge is beveled and has the eliptical curve allowing the barrel shape. You will still need to cup out the inside of the stave free hand, as well as shape the outside of the stave; unless you are planning on doing this with a CNC set up. Cupping the inside is a variation on the process used for making eyeglass lenses which is often done using a custom Bosch router motor and a ball shaped cutter. Unless you are a retired engineer/programmer looking for a project this would be cost prohibitive. Professor Roy Underhill had an excellent episode about barrel making on "The Woodwrights Shop" which airs on PBS. I believe the cooper that made the presentation was from Colonial Williamsburg, VA. You might be able to get a copy of that show on VHS tape.
 

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Great link(s) Ed

One mans Junk another mans Treasury , I'm always astonish and amaze what people
can come up with :)
Some people just see a old barrel and some see a beautiful chair made from the old junk barrel.

Bj :)
 

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bobj3 said:
Great link(s) Ed

One mans Junk another mans Treasury , I'm always astonish and amaze what people
can come up with :)
Some people just see a old barrel and some see a beautiful chair made from the old junk barrel.
bobj3 said:
I have my eye on stealing a few ideas from them and give them my twist...

Ed
 

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I think you should wander down to KY and pick up a barrel or two (full of course), we'll get a hundred or so members of this forum together an help you empty it, and then you can have the empty barrel !!!!!!
steveo
 

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Discussion Starter #9
I like the idea of getting a barrel or two to empty. I vote for a barrel of Bookers and another of Basil Hayden. Who is chipping in?

I haven’t drawn a stave up yet. However I can say with fair confidence that the edge geometry is nonlinear as the barrel diameter decreases while the sphere increases on the approach to the ends. It’s kind of hard to visualize.
I think as some have suggested that a fixture may be the only way to go. I have never even been in the same state as an older barrel stave making machine. The engineers who tackled that problem must have been quite bright.

Part of the problem with making that first stave is - well – making that first stave. It’s got to be dead true and perfectly sized as I don’t want to end up in the old cooper’s position of having to hand fit the final stave. Each stave must be the precise increment of the fully formed barrel. Hand coopers don’t worry about that as they are going to make that last stave to fit “just so.” Instead they have perfected the craft of making the staves in general so making a large-ish or small-ish final stave is not a big deal at all.

If I can’t make that first stave I can’t make a barrel no matter whether I use a router or a hand shave. I can’t cheat and reverse engineer an existing stave, simply accepting the diameter it produces as I have diameters fixed by other factors determining the diameters I need to produce.

I have considered giving up (ARRRGGGHH) and making the geometry a straight sided “bucket type” shape. Even though I will eventually do exactly that a straight sided geometry will not give me the sound I want on this go round. Straight sides and barrel shapes each produce different resonance patterns. Did I mention I want to make percussion instruments - drums? Drums can be every bit as demanding and exacting to manufacture as violins. Sadly they are also terribly easy to mass produce when no regard is paid to the finer points of tone and timbre. The glue in mass produced plywood drums does to the drum’s tone exactly what the glue in a plywood guitar does to the tone of the guitar. It wrecks it. So also does inattention paid to the materials. The shape and material selection of a mass produced plywood drum is dictated by economics and not the aesthetics of the sound produced. Most people won’t ever notice it.
 

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The Formulars for working out the widthof a stave useing bird,s mouth router bits
6 sided object is Width=Diameter/1.7
8 sided object is Width= Diameter/2.4
12 sided object is Width=Diameter/3.7
16 sided object is Width= Diameter/5.0

So if you work out the diameter for the ends and the diameter for the middle you should be able to cut the stave.


Big butt, bend over known as wedgetail
 
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