Fabulous. I love the discus shape and the way it intersects with the flat surface of the ash.
I'm struggling to see just how the cabochon was inset into the complex shape present in the centre. Care to share your secrets?
Duncan
...not sure I can explain this in writing, but here goes...
1...When the disc was still circular, a 4mm-deep, 90mm diameter recess was cut in the centre.
2...The oak burr cabochon is 100mm diameter, but has a 90mm tenon on the back of it, just shy of 4mm long....so it sits snugly into the recess, which it overhangs by 5mm all round to hide the edge of the recess.
3...The disc was then cut into 3 segments, the shape of the central segment matching the shape of the black-ash pinnacle. Thus the disc became two wings and a central piece, which was discarded.
4...The two wings were dowelled and glued onto the long edges of the black-ash pinnacle, with great care being taken to exactly line-up the edges of the 90x4mm recess with the front face of the pinnacle, then left to dry
5...the oak burr cabochon was placed in position over its recess, which it couldn't drop into because of the solid, front face of the pinnacle.
6...at this point, I had 2 options...
...option a....mark a pencil line around the cabochon, on the face of the pinnacle and then use a router set to 4mm deep, to cut out the rest of the recess
...option b...make pencil marks where the edges of the pinnacle crossed the tenon on the back of the cabochon and then chisel-away, by hand, that central portion of the tenon.
7...I settled for option b and turned a block of sycamore into a jam-chuck, pressed the cabochon (face down) into it, laid it flat in a bench-vice and cut away the excess central area of the tenon. This left the tenon looking like two segments of an orange, one on each side, and those two segments fitted perfectly into what was left of the 4x90mm recess.
8...the cabochon was glued into place with plenty of epoxy adhesive.
Les