Also take into consideration that the Balearic home is an island. Slinging at sea level is not the best place to try slinging for distance.

When I was slinging rocks at the sea, I was surprised to see that my shots fell short of my usual distance. I quickly realized that the thick atmosphere was slowing my rocks.

Rockman wrote on Feb 12^th, 2011 at 3:00pm:


Leaden projectiles due its density aren't as much sensible to air density or wind as stones. I have done the attempts 72 m over the sea level and there was frost. Of course if one have a perfect consistent technique it could be significant.

I disagree with the drill part, unless the gland is rotating at speeds approaching electric drill speeds, plain old momentumn is what is going to make it dig into the ground.  And for a small projectile, it doesn't have to go all that deep to make finding it almost impossible.  Bill

The rpm maintains an on axis flight and hopefully a point first hit. No meaningful drilling takes place because of the low rotation rate per unit of distance, which can be as low as 3 turns in each lineal meter. The penetration is solely determined by impact force, nature of projectile and target.

HYPOTHETICAL  SLING  

50 mps ave. @ 50 m gives 150 turns in 1 second and 9,000 rpm

HYPOTHETICAL RIFLED FIREARM      

500 mps ave. @ 50 m gives 150 turns in .1 second and 90,000 rpm

Curious Aardvark wrote on Feb 14^th, 2011 at 12:40pm:


Sorry, Old Chap, I've heard you make that claim before. Whilst I cannot prove it to be untrue I suspect you'd have a devil of a time proving it is.

Sure the gland is spinning rapidly, but it's also moving forward very rapidly so the ratio of spin to travel is really quite low. Even when drilling soft materials a drill advances only millimetres for every revolution, and then under power. A sling projectile has only a very small percentage of its kinetic enery due to rotation, nearly all is due to forward motion.

The spin is essential in keeping the gland flying point forward, exactly the same as a rifle bullet. This materially aids in accuracy, but I doubt it adds much to the striking force.

The majority of the spin on a projectile is induced as it comes out of the pouch on release. There is also some due to the actual rotation of the sling but this is comparatively small. The pouch does not let go instantly but opens from one side allowing the projectile to roll out. So, the rate of spin varies considerably dependent on the centrifugal force, the diameter of the projectile, the degree of grip between the projectile and pouch, etc. I know from observation that when I sling tennis balls they rotate comparatively slowly; I estimate no mor than ten revs per sec or 600 RPM. However judging from the sound of small whirring stones, similar to the sound of transformers, I estimate their rotational speed to be up around 3000 RPM.

Morphy wrote on Feb 2^nd, 2011 at 1:59pm:



It's good to know that I'm not necessarily doing something wrong because I don't get a whip-crack on my release. My slings make a sound a lot like Larry's did in that video.

I'd love to be able to sling a golf ball farther than good golfers can drive them. It's been a while since I got out with a bag of balls on a long open field. Have to do that again soon. I've done some slow-and-easy practice (as I've posted about here) and I do feel a need to get out and cut loose, soon.