Papua New Guinea Spearthrower, made from 1 piece of wood.
Wood, 21 1/4" x 2 1/4" x 3/4"
Cut out the handle and peg ends as shows. It may be easier to do it in 2 steps for each end - for the handle end, 7" from the end cut down 1 1/2", then go straight out to the end. Cut 1 1/2" from the resulting block and taper it to the same place.
Thin the dart guide. Starting 3/4" from the bottom of the left side (while looking at the peg end), taper it to 1/8" wide on the top.
Cut the notch for the groove. Starting 1/2" from the peg end, cut down 1/4" and slant it up to the guide.
Carve out the groove. Go at least 3/8" wide and 1/4" deep, slanting up to the edge of the guide.
Make the handle round.
Round off the bottom.
Round off the peg end.
Round off all edges and sand smooth.
There are two different ways to throw with a Papua New Guinea style. I've described the methods here.