Rat, those will work great. i know of several people who have used them for darts. i, myself, have used them for foreshafts on my shark darts. no, you don't have to put a spin on the fletchings if you don't want to.

Rat, i've thrown with both types of darts (spin and no spin) and haven't been able to tell the difference. it doesn't matter if you use right or left wing feathers, just as long as you use the same on any single dart.

  Well, I don't know a lot about atlatl's but generally something with a rifle spin will go farther than without.  For example a biconical clay shot, black powder guns without spiral rifling in the barrel do not go as far as with it, but this may not be much of a difference with atlatl darts, idk, but too much spin is also bad as the feathers will drag and slow the arrow down a bit.

So u dont need the fletching at all? Dose it make a big diffrents if there is or is not any fletching?

Thank for taking the time to share or info paleoarts

fletching it is 

it might, Dog, but i'm not sure. anything that trailed behind the dart i would worry about getting fouled with the atlatl itself during the initial cast. a simple two feather fletch crudely tied on will work just fine. in fact, this was how the ancient Basketmakers did it and they hunted some pretty big prey to great success, so... 

yeah, Walter, tail down is a clear indication of too rigid a spine. it's the flex of the dart that allows the front and back ends to stay in line and the dart to fly straight. if you are using some kind of cane or bamboo, try fitting a longer foreshaft. this increases the length of your dart and will add to the overall flex. if you are using solid wood darts, you can try adding weight to the front, or tapering the back 2/3. either should increase flex. test your spine by putting one end on a bathroom scale and pressing down on the other. whatever the weight tops out at is your spine weight. darts range anywhere from 4 to about 13 lbs with 7-8 being the norm for darts of around 6' in length. as a general rule, the longer the dart, the more spine you can get away with up to a point.

Chris