JReed: Thanks for posting on one of my favorite topics. Tom Mills --Paleoaleo on Youtube -- has a wonderful Web site called Paleo Planet, and one of the forums is the home of the World Atlatl Association. Each year in late spring, they have an atlatl get-together at the Valley of Fire near Las Vegas, camping among rock formations that bear original rock drawings of hunters using atlatls!
I've made a dozen or so, and have found the simple, slender "basketmaker" styles the easiest to use. My two favorites are made of juniper and hazel. I find the much stiffer throwing board types awkward. My favorite tools are a small finger plane, a draw knife and some small gouges for cutting the notches and hollows.
I traded Oregon obsidian for a batch of Kansas river cane for shafts. I find the cane works best with a "foot" of fire-hardened hazel, as it needs weight forward to fly well and store energy. My favorite dart material by far is red osier dogwood, which is abundant in the Pacific northwest along mountain streams. It's great for a number of reasons that native peoples appreciated. It grows relatively straight, and is easy to straighten by hand or with a bit of heat. It peels easily, and it normally has a very uniform taper. I like darts in the 5-7 foot range, and spining around 7 pounds. Engineers who have studied the atlatl system concluded that the atlatl itself extends the leverage of the arm, and the dart, when of the right spine and material, stores energy like a spring. That snakey motion you see is that spring energy helping propel the dart to the target. A too-stiff dart is lifeless on the throw. My first darts were made with hardware-store dowels. Worthless! I couldn't believe how the atlatl came alive with a proper dart.
Tom Mills makes his of Arundo donax, a large grass reed that infests much of California.