Sunday, April 8, 2012

resolving the back of a harmonic box

Finally, this harmonic cone has me by the hair. It's good to have a creative problem beckoning, and I'm just now entering the 'flow zone'- where an unfamiliar set of problems is unfolding, but enough is coming together to tickle the right-brain cells into imagining the next phase with some excitement.

Above, the cone has been cleaned up a little, and although it is amazingly tough, the shape is at it's most vulnerable stage.

Below, the unit sits in the cradle being set up for the angled base and cap. These angles are pretty important and the fit is complex so I ended up making a jig based on Rick Kemper's one, and I found it very handy to check symmetry, and angles in all directions while fitting the 'bulkheads', and then when gluing them.

In the pic below, one of the linings are being glued in after the central bracing 'bulkhead' has been fabricated to fit between the middle and lower sound holes- and these were just cut and left rough at this stage.

And here the sound box leans provocatively on the jointer inviting me to enjoy the angles, staves, facets and taper. Those holes are still rough, and will be faired with knives and birdsmouth files when I'm in a mood for finer, more focussed work. The off-cut from the base angle can be seen on the saw bwnch behind the jointer- one of the more enchanting of off-cuts...I wonder what I could do...


  1. Fascinating Dad! She is looking wonderful :)

  2. Vulnerable was my first thought. Everything must be just so.
    I'd make a compass box from that off-cut.