Official Luthiers Forum!

Hi everyone,

Just surfacing from my lurker mode:

I was just looking at some of the heavily arched tops from Dave White/ Nigel Forster / Stefan Sobell/ Laurent Brondel

and was wondering to those who build such tops tend to induce the arch/cylinder by forming the tops to the heavily radiused braces? I seem to read that some of the construction techniques do not involve this? Any help would be greatly appreciated!


Terence

I use "cylinder" arching for the octave mandolins I build. I use a combination of arched X braces and "arched sides". I use a sanding board to put the arch in the sides similar to what we do for "doming" sides. To make the sanding form I took a piece if 1/8th inch plywood, covered in sandpaper and tacked it down in the middle to a piece of 3/4 ply. I then used sticks under the long edges that could be moved in or out to create more or less arching. To arch the rib assembly you move it up and back without too much side to side motion. I haven't motorized this operation, so placing the rib assembly on the sanding board and drawing around the inside with a pencil and then planing to the line can save some elbow grease.