How did you settle on the 6’10” darts?
Ray here: I found out by trial and error that longer darts are easier to control as regards accuracy. Its a matter of kinetic flexibility. Shorter darts are springy, flex out, flex back in a hurry. This means any slight change in throwing speed results in an immediate hyper reaction with dart flex. Longer darts are less kinetic and tend to allow slight changes in throwing motion to have little effect in their flexing motion.
Aluminum and carbon darts are hyper kinetic compared to bamboo and river cane. Bamboo is slightly more kinetic than river cane.
How do you match weight/lenght? I take a river cane about the right size, put duct tape on for fletching, put on a point and start throwing it. They are almost always too limber, so I start cutting them down little by little til they fly good, then I feather fletch. I guess that is what I meant by tuning.
Ray here: I choose dart shaft stock (bamboo or river cane) first by length, then by diameter at the base and rear end. Total length of the dart shaft is about 6 feet long with a foreshaft 12 inches long (with two inches of the foreshaft inside the cane), thus 6’10″” overall length.
I look for the base to be a little less than 5/8 of an inch in diameter (narrow enough that when string and glue is added it can still slide through the WAA’s maximum allowable diameter for the ISAC competition). The rear end needs to be 3/8 of an inch in diameter.
If you start with a 7 foot or 8 foot length of bamboo or river cane, you can probably get exactly what you need for a 6 foot length.
River cane and bamboo grow naturally into a dart shaft that is thicker and heavier at one end than the other and therefore, after adding a 12 inch foreshaft and 1 1/2 long 1/4 inch diameter copper point, I don’t need to adjust the dart shaft for balance as mother nature has already done the work for me.
Bamboo and river cane are not cloned, therefore each is a little different. I like my darts to be a little stiff. The way I check the dart for the right amount of stiffness is to hold the dart shaft horizontally chest high, hold the narrow in of the dart in one hand, reach out about two feet with the other hand and wag the loose big end up and done briskly but not wildly. If the loose end travels up and down between 12 to 18 inches, that’s what I want. If it wags greater than 18 inches, its too limber. If it wags less than 12 inches, its too stiff.
Mine are all under 5′- 6′. I have trouble matching them weight/lenght, I know this is important for consistancy. Mine all weigh 3-4 oz.
Ray here: I think I pretty much described how I choose dart lengths and diameters above. As far as matching, I may straighten 12 dart shafts (all the same length and diameter) before I find 3 that are a matched set as far as stiffness and overall balance and weight are concerned. That is just the nature of beast. Seek and straighten and ye shall find. Out of the 12 dart shaft, if I am lucky, I will find 2 or 3 sets of 3 dart shafts that are well matched. My darts are on average about 6 ounces in weight.
Also is there a picture of how you grip the atlatl with the hole in the handle?
Ray here: Check it out here: