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Calculating Theoretical Sling Range (Read 17968 times)
David_T
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Re: Calculating Theoretical Sling Range
Reply #15 - Jan 22nd, 2004 at 2:12pm
 
I once read an accout of a Roman slinger as to projectile speed.
He observed that if you saw an ememy slinger release his stone at the same time you did and his stone hit you before you saw him fall---you were slower than he was. Grin Grin
Its my lunch break what can I saw Roll Eyes
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David_T
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Re: Calculating Theoretical Sling Range
Reply #16 - Jan 22nd, 2004 at 2:15pm
 
I meant: ...what can I say
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Yurek
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Re: Calculating Theoretical Sling Range
Reply #17 - Jan 22nd, 2004 at 4:34pm
 
David,

Just the great idea of the projectile velocity measurement! We must try it! It is just absolute measurment! LOL

Jurek

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In the shape, structure and position of each stone, there is recorded a small piece of history. So, slinging them, we add a bit of our history to them.
 
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Hondero
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Re: Calculating Theoretical Sling Range
Reply #18 - Jan 22nd, 2004 at 4:50pm
 
Humm, to be exacts I think the David method has some deficiency as it dont´consider the velocity of the light. So, the slinger that see the enemy falling when he is struck has thrown to higher speed than him  Shocked  Grin
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He brought a conquering sword..., a shield..., a spear... , a sling from which no erring shot was discharged.&&
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Yurek
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Re: Calculating Theoretical Sling Range
Reply #19 - Jan 22nd, 2004 at 5:09pm
 
Hondero,

Probably David assumed that a velocity of the missle is greater than the light velocity  Grin

Jurek
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In the shape, structure and position of each stone, there is recorded a small piece of history. So, slinging them, we add a bit of our history to them.
 
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Ulrica
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Re: Calculating Theoretical Sling Range
Reply #20 - Jan 22nd, 2004 at 5:18pm
 
Hi...

I´m totally green in this subject, but I just got an idea...
( maybe it was the Champange??)

Well, is there somewhere, something you can throw that can measure the speed in the air when it´s flying?
I mean like a watch but something that measure the stream of air???
I don´t know if such thing really exciced...  But maybe there is??

Just an idea.....
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May the stones go your way&&&&//Ulrica
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Yurek
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Re: Calculating Theoretical Sling Range
Reply #21 - Jan 22nd, 2004 at 5:23pm
 
He he

That thing is an anemometer, so just we must throw the one Wink

Jurek
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In the shape, structure and position of each stone, there is recorded a small piece of history. So, slinging them, we add a bit of our history to them.
 
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mgreenfield
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Re: Calculating Theoretical Sling Range
Reply #22 - Jan 25th, 2004 at 1:45am
 
Jurek, .....I went to your www.scri.fsu.edu/~jac/Java/baseball4.html site & tried a little "experiment".    

I launched a baseball in the simulator at 93mph, an angle of 35deg.  It "flew" 330ft.

I assumed the baseball sphere had a volume of 8 cubic units.

I found the circular area a flying sphere of 8 cubic units presents to the oncoming wind.  It is 4.75 square units.

I "rearranged" these 8 units into an almond shaped glande that flying point-first would present just 2 units to the oncoming wind.

The same almond glande flying edge-first would present 4 to the oncoming wind.

The same almond glande flying top first would present all 8 units to the oncoming wind.

My estimates are these.    If my spherical glande could fly 330feet, my almond glande flying point first (best case) could make 430feet, ....almost 1/3 farther than the sphere.   Worst case is my almond glande flying flat-side first, making just 277feet, ....which is 15% less than the sphere.

Here's the kicker, ....a well thrown (point-first) glande in my "experiment" "flew" 432feet, ....which is over 50% more distance than a poorly thrown (flat-side first) glande at 277feet.

If the above is pretty much right, why would ancient slingsters throw almond glandes if they couldnt control them go point-first?   Distance results and therefore accuracy of "uncontrolled" almond glandes are just too variable.    I say, if they had not means of controlling the almond glandes, they would have thrown spherical glandes.

What do you-all think??    mgreenfield
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Yurek
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Re: Calculating Theoretical Sling Range
Reply #23 - Jan 25th, 2004 at 2:05pm
 
mgreenfield,

Your experiment is interesting. I'm a bit surprised that you have got so big differences between the ranges in the different kinds of fligh. Yesterday I tested a few ball shaped and elongated lead projectiles on the frozen lake. But, alas, I didn't find any of them. All projectiles were lost because there was too much snow and the traces on it, and I hadn't too much time for seeking due to grow dusk. One day I will repeat it.

But, at a guess, the range differences didn't seem so big, although the launch velocities had to be bigger than that one which you tested. The bigger velocity, the bigger shape influence for the range.

Surely, the reason is in a big desity of the lead projectiles relative to the baseball density.

Anyway your tests confirm our common opinion about adventage of the elongated projectiles in the "point-first" flight over other ones. I think you are right about the reason of using the almond shaped glandes by the Romans.

Jurek
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In the shape, structure and position of each stone, there is recorded a small piece of history. So, slinging them, we add a bit of our history to them.
 
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mgreenfield
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Re: Calculating Theoretical Sling Range
Reply #24 - Jan 25th, 2004 at 4:10pm
 
Yeah, Jurek, I suppose the real-world range and accuracy differences between well thrown & poorly thrown glandes will never be as dramatic as my estimates of best case and worst case.    In real life a well thrown glande is still never "best case" thrown, and a poorly thrown glande is still never "worst case" thrown.    Plus there are a lot of other variables in every throw that hide the effects of glande orientation in flight.    So, it will be tough to tell really how good a job a slingster is doing.   

That aside, I figure no slingster will make it to "world class olympic" status without getting a LOT of glandes off point first.    That will be the difference between a world class slingster and a simple rock-chucker like me.

I have cast some 80gram plaster of paris eggs, which I will paint one side white and one side red.  I plan to sling them "softly", and watch them closely to see if I can learn a technique that puts point-first NFL football spins on them most of the time.

But it's gotta get warmer outside!!    Last week or so it has been -20 to -3 Celcius all the time here in Wisconsin USA.

Happy potato chucking!        mgreenfield
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JeffH
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Re: Calculating Theoretical Sling Range
Reply #25 - Jan 25th, 2004 at 4:44pm
 
I have slung a stones of varying size, weight and shape.  I have achieved 400 feet or so with these widely varying stones.  I am not, therefore, convinced, that the difference in shape is going to have as much affect on the distance as the baseball program suggested.

Certainly some elements of the stones shape and weight will affect distance.  But without good experiments, I distrust the software.

jeff <><
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So David triumphed over the Philistine with a sling and a stone. (1 Samuel 17:50)
 
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mgreenfield
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Re: Calculating Theoretical Sling Range
Reply #26 - Jan 26th, 2004 at 9:38am
 
Right you are, Jeff.   Looks to me like we have guys doing pretty consistent long-range rock-chucking.   I'm concerned about possibilities of putting (say) 4 out of 5 rocks in a washtub at (say) 400yards.   Ancient writings are full of tales of hair-splitting sling accuracy, ...makes 'em sound even better than bow & arrow.    How DID they do that??    Or is much of this writing hot air, .....my army slingsters can beat your army slingsters, etc.    Further, if slingsters were known to be such crack shots, why didnt Goliath just throw down his spear & run when David showed up??  Inquiring minds want to know!   Smiley  mgreenfield
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David_T
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Re: Calculating Theoretical Sling Range
Reply #27 - Jan 26th, 2004 at 12:31pm
 
If we lived in the Belaric Islands off Spain we would not doubt the accuracy that the sling is capable of in the right hands. I'm really hoping Hondero can get videos of some of the competitions they have over there. It would help us non-experts see exactly how they sling and how good they are.

As to Goliath, my theory is that David did not "telegraph" the fact that he had a sling. Scripture says that Goliath was angered and mocked Israel and David for sending a boy with a stick (staves) to fight him (I Samuel 17:42-43) Goliath definately saw the stick David had not the sling.  I believe that Goliath, in his pride and anger, came at David, and amazingly, David ran to meet him. It says that at that point David reached into his shepards bag, got one of the smooth stones and slung it. I believe that Goliath probably did'nt figure out what was happening  until one or two seconds before he went cross-eyed trying to see what was coming at his head. Grin
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mgreenfield
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Re: Calculating Theoretical Sling Range
Reply #28 - Jan 26th, 2004 at 2:34pm
 
I would love to see the Belaric Is guys do their sling thing.   Maybe we take up a collection to pay Hondero's way there w video equipment, ....full speed & slow-motion to record exactly how the slinging job is done.    I'd sure kick in some decent $$ to see this tape & hear what Hondero said about it.   Maybe we meet someplace in USA to see, hear, discuss, practice.   (Which means also taking up a collection to help Jurek, Ulrica, Hondero, others buy air tickets  Grin)

I figger slinging is like golf, ...get the Form & Technique down, and everything works fine.  Without the F&T, nothing works very well.     I feel like a guy who's been handed a golf club and ball, who's never even seen the game played on TV.   If Hondero goes to the Belaric Is, he gets to be the first modern Internationally Known Sling-Pro.

mgreenfield
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Ulrica
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Re: Calculating Theoretical Sling Range
Reply #29 - Jan 26th, 2004 at 3:05pm
 
Sounds great to me. I would like to fly to USA and meet you guys! And almost for free... even better Cheesy
But why doesn´t we all go to spain and see it live?  8)
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May the stones go your way&&&&//Ulrica
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