Here is a simple jig that allows you to cut a complete lute neck block on the band saw.. A base plate clamped to the band saw table provides a pivot for the movable mounting arm holding the neck block.
First you need to measure the approximate radius of your lute shape in the neck block area. I am building two lutes after J.C. Hoffmann and the radius is about 8.9". This radius gives you the dimension from your fixture pivot point to the band saw blade..
Next, mark the inside surface of the neck block with radial lines that go through the CENTER of each rib.
The neck block is mounted to the cutting jig. The gold-colored mounting screw forms the axis for rotating the neck block with each successive cut. The screw needs to be tight when cutting, but can be loosened to rotate the block for the next cut if needed.
After making each cut, rotate the block to the next rib line on the block. Notice a small reference mark for horizontal is placed on the fixture. Just match the line on the block (which represents the center of each rib) with the reference mark and make the cut.
Here the neck block has been rough cut and removed from the cutting jig. Notice that there is extra material remaining that was necessary for initial mounting to the cutting jig.
The extra material is easily removed..
The finished neck block - ready to attach to your mold or assembled back.
This back (of myrtlewood) was built without a mold and the neck block was put in after all the ribs were assembled. It fit very well, but was tricky to find good clamping positions while gluing. If you are building with a mold then this is not a problem as you will be attaching ribs to the block as you go.