JWaldo
Aluminum
- Joined
- May 4, 2011
- Location
- Northern Virginia, USA
I've got to build a jig for a small production run.
My initial assumption was, wider in the middle, narrow at the ends, just draw in a fair curve and you're good to go.
Wrong. (at least, the trial pieces didn't work)
So, mathematically, I've got a curve section, turned into a curved sheet that intersects a plane at an angle. Slice it off at the plane intersection, flatten it out, and there's the plan pattern for the stave. College 3D geometry was 40 years ago, and while I vaguely remember intersecting cylinders with planes at angles, I don't remember enough of the math to do it now.
Rather than try to re-create the math, does anyone know of a stave pattern calculator available anywhere? (I've searched the web extensively - it's like any pattern is the super secret, only if you know the handshake, ingredient - perhaps only given to apprentice coopers after 10 years of slaving?) Lots of stuff on making barrels, some video, but nothing so far on the actual plan pattern for a stave. Could do a trial and error, but would like to take a more engineered approach.
Thanks,
Jim.
P.S. Yes, the sides of the stave's are beveled. Got that part worked out (% of circumference * 360 / 2). It's the plan view of the stave that's giving me trouble.
My initial assumption was, wider in the middle, narrow at the ends, just draw in a fair curve and you're good to go.
Wrong. (at least, the trial pieces didn't work)
So, mathematically, I've got a curve section, turned into a curved sheet that intersects a plane at an angle. Slice it off at the plane intersection, flatten it out, and there's the plan pattern for the stave. College 3D geometry was 40 years ago, and while I vaguely remember intersecting cylinders with planes at angles, I don't remember enough of the math to do it now.
Rather than try to re-create the math, does anyone know of a stave pattern calculator available anywhere? (I've searched the web extensively - it's like any pattern is the super secret, only if you know the handshake, ingredient - perhaps only given to apprentice coopers after 10 years of slaving?) Lots of stuff on making barrels, some video, but nothing so far on the actual plan pattern for a stave. Could do a trial and error, but would like to take a more engineered approach.
Thanks,
Jim.
P.S. Yes, the sides of the stave's are beveled. Got that part worked out (% of circumference * 360 / 2). It's the plan view of the stave that's giving me trouble.