Some of you pro aerodynamics geeks need to verify somethinfg for me please.

I am going to make some lead glands with fins molded into them to see if it will make them fly exta staight.

Assuming that I am right handed and using an OVERHAND cast, the spin caused by the release is in a clockwise or left to right direction. I am sure this is correct.

My question is: if the gland is in front of you and pointed straight ahead, would the fins need to be running diagonally from front right to back left on the gland to give it the same rotation as the release? If they are not in the right direction they will be fighting the rotation caused by the release.

I apreciate the input

I am thinking about making the front point of the gland being able to accept some type of arrow type tip that would give it cutting action for penitration. Something that would screw into it and not be too bulkie to hang up in the pouch.

It will be a pain to get this "right". The twist is same as a rh screw, like you both said, but the angle is going to be important too. Get it wrong to either side and the fins will be slowing down the glans (trying to spin faster if too shallow a pitch and slowing it down if too steep). Add to this the disturbance to the flow and I'm not certain that you have a winning proposition. The force exerted by the small fins over a short moment arm will probably be too small to fight the "gyro stabilisation" effect of the spin as well, but we'll never know unless you try! I expect that they will look pretty trick no matter what 8)

You want to try a couple of experiments for the sake of advancement of sling physics David? (and you other rifle-spinners out there?) Pick of some plastilene clay and make some prototype projectiles (if you are keen make them bi-colour!) and then throw them close range at a solid wall. Photograph the results. Then throw them long range at a wall (hitting the proverbial "broad side" ) and compare. I would like to see the attitude at impact...

Might be worthwhile for testing ideas like fins as well if you have a range where you can recover ammo and they wont get _too_ dirty. Make the test glandes big enough for appropriate weight and the effects will scale down for lead. If the clay available is too soft, bringing a bucket or cooler of icewater should stabilise them nicely.

Matthias

I used to punch holes in things with my sling, but you sort of lose track of how much power you are actually putting behind your projectile when most of your shots go out into the ocean. Pegging my ballistic pendulum to the ceiling a couple of times was an eye opener - I'd underestimated by about 3 the mass needed to absorb the impact force. Equally impressive is the flattened diameter of the clay glans on impact with the wall when I miss the target. Methinks at close range, pretty much any projectile is going to pulverise a turkey, let alone penetrate it

Matthias

squirrelslinger wrote on Feb 11^th, 2013 at 2:59am:



I was trawling for info on slingstones and glans plumbata dimensions only to find this.

That's the only thing I know of that would make C_A wig out.

[quote author=BRENT link=1151350360/0#8 date=1063494426]one trouble with making ammo is losing it.but,i have an answer.go to micheals or an art store and buy the clay brand Sculpey,yep i spelled it right,buy the atomic orange color its really blaze orange but they call it atomic orange. Make it into a ball  and bake it you wont easily lose your ammunition.
Brent    [/quote]


Hi, just wondering, what kind of results can I get merely baking clay?  Is there a good way to make a homemade kiln?

What David said.  I fire mine, I have a kiln and I pit fire, also.  It makes good ammo even better, the fired clay will break pine boards.  But, you still lose it so I usually just make up some and let it sit until I have a load of pots to fire.