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General >> Here Be Maths... >> Chronographs! https://slinging.org/forum/YaBB.pl?num=1534470400 Message started by woodssj on Aug 16th, 2018 at 9:46pm |
Title: Chronographs! Post by woodssj on Aug 16th, 2018 at 9:46pm
Hello All,
Attached via the links is the form for submitting results, and a way to access the results as they currently stand. Submit Results Here! https://docs.google.com/forms/d/e/1FAIpQLSfH7aKd7YyHN6R55MAhaF-x0dtwcOBNM0HMvzyTYWIl5A0iNg/viewform?usp=sf_link Access Results Here! https://docs.google.com/spreadsheets/d/1SA9v0WGYd4ppDte8GXRtFTluwcKb8vNyJNEegpx0HCE/edit?usp=sharing I'd appreciate if you'd attach your results for each throwing session to this thread, and to make that easier, I happen to have a really simple form to fill in that has all the details you'll need for up to 80 throws. That's a lot of throwing. The reasons for attaching your scanned or photographed results here, is that the study only asks for fastest, slowest, and average throw from your results. Your more detailed results will allow us to create a more detailed picture of the gathered aggregate data, and then we can periodically drop that off in the Data Publication Thread for your enjoyment. Thank you for all your help! ![]() |
Title: Re: Chronographs! Post by Mersa on Aug 26th, 2019 at 4:29am
Yesterday I was able to pass one unweighted stone through someone else's "pro chrono" chronograph .
105fps |
Title: Re: Chronographs! Post by Kick on Aug 26th, 2019 at 8:56am
That's awesome!
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Title: Re: Chronographs! Post by woodssj on Aug 26th, 2019 at 11:30am
105fps is pretty good, especially if you're looking at heavy projectiles.
32m/s or 71.6 MPH. Also, that's a small window to throw through. I'm Impressed! |
Title: Re: Chronographs! Post by IronGoober on Apr 22nd, 2020 at 11:05pm
I added my data to the spreadsheet. It seems the only other entry is in mph, whereas the spreadsheet specifies "m/s".
Here is the video from the data in the spreadsheet, this was almost full power, from 16 yards. https://www.youtube.com/watch?v=RQ3bAICVD8M |
Title: Re: Chronographs! Post by woodssj on Apr 24th, 2020 at 3:49am
That's some pretty impressive numbers. We've only got two samples at the moment, but with any luck, we can build some pretty good ranges of velocities and energy.
It's looking to be about 5.2 Kg-m/s of energy on average for your throws, and that's not a small amount. |
Title: Re: Chronographs! Post by Logan757 on Jul 8th, 2020 at 4:48pm
add newtons or ft/lbs of energy to your data i've heard that with lead bullets slingers can get up to 9mm power or around 350 ft/lbs of energy which would require a 2.89891304339 pound projectile at 36.8 m/s or 120.7349 ft/s and then the other guy would have to sling a 1.90500035379 lb object at 183.727 ft,s or 56 m/s and a nat geo article "The Roman slingers would have exacted a heavy toll. Recent experiments conducted in Germany showed that a 50-gram Roman bullet hurled by a trained slinger has only slightly less stopping power than a .44 magnum cartridge fired from a handgun" https://www.nationalgeographic.com/news/2017/05/ancient-slingshot-lethal-44-magnum-scotland/#close which would require the slinger to get speeds of a center fire riffle something isn't adding up here either we realy suck at slinging are using the wrong projectiles or people have drasticly over estimated the power of a sling
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Title: Re: Chronographs! Post by Logan757 on Jul 8th, 2020 at 5:02pm
https://youtu.be/_1oeZQH4oEc this guy says that they would throw at 240km/h or 218.723 ft/s or 66.666770388894 m/s which is a lot higher than what we are getting but very believable https://youtu.be/w_nWywEmWMg this is some deep potato version of an actual documentary which he gets a force not energy measurement of 3.6 kilonewtons
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Title: Re: Chronographs! Post by Mersa on Jul 8th, 2020 at 7:46pm
Have you looked at the numbers for momentum?
I haven’t checked your maths but it’s pretty achievable to hit 30-70m/s and projectile weights 50grams. I think 52m/s and a 200g projectile was recorded by Luis |
Title: Re: Chronographs! Post by Logan757 on Jul 9th, 2020 at 1:47pm
The record is just under a hand gun calibers energy
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Title: Re: Chronographs! Post by woodssj on Jul 26th, 2020 at 5:37pm
I wish that NatGeo article cited some sources. You'd think we'd be aware of such studies, being experienced slingers they would call upon. Does Mr Jeagor know anything about this?
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Title: Re: Chronographs! Post by NooneOfConsequence on Jul 28th, 2020 at 11:49pm
If you look at bow hunting, big game can be taken with 65ft-lbs of energy using a bow and arrow. A humble .22lr bullet has twice that kinetic energy coming out of a rifle. I think we are overestimating the energy required for a projectile to be deadly, but something definitely does not add up in that natgeo estimate. I don't see how you get to .44 magnum energies unless the mass of the sling bullet is enormous... and we know that the Romans used relatively small sling bullets most of the time. Maybe they are comparing the energy of a sling bullet to a .44 revolver (not the bullet) that was being thrown at someone by hand???
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Title: Re: Chronographs! Post by Bill Skinner on Jul 29th, 2020 at 9:36am
Arrows kill by cutting and blood loss. Bullets do the same thing but also add the shock of the impact.
A stone thrown by hand can have enough impact velocity to rupture organs and break bones, a sling just increases the velocity to cause more damage. I don't think you can really compare a crushing projectile with a cutting projectile. |
Title: Re: Chronographs! Post by KnollSlinger on Aug 21st, 2020 at 11:38pm
The sling can chop a large jack rabbit in half. I've done it. Not even using a hard throw.
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Title: Re: Chronographs! Post by IronGoober on Sep 27th, 2020 at 10:54pm
I have some data to share from today's session. Measurements of velocity were made with a PocketRadar, throwing away from it. I was using a 72cm sling (from inside of pouch to center of fingers when in retention loop, i.e. the radius)
Tennis ball: 57.6 g Throw 1: 110 mph (49.17 m/s) Throw 2: 107 mph (47.83 m/s) Throw 3: 112 mph (50.07 m/s) Throw 4: 115 mph (51.41 m/s) Throw 5: 116 mph (51.86 m/s) Rusty balls: 160.2 g, 159.8 g Throw 1: 104 mph (46.49 m/s) Throw 2: 100 mph (44.70 m/s) Throw 3: 101 mph (45.15 m/s) Throw 4: 101 mph (45.15 m/s) The error is about 1 mph (~0.5 m/s). (according to a comparison with a high end radar gun) |
Title: Re: Chronographs! Post by IronGoober on Sep 27th, 2020 at 10:57pm
Also, check out these from Sarosh! Good stuff!
https://www.youtube.com/watch?v=Czg3VgZftco https://www.youtube.com/watch?v=ceaaplf_8FA Reference for how it was measured: https://www.youtube.com/watch?v=ocSaiDboFTQ |
Title: Re: Chronographs! Post by IronGoober on Sep 29th, 2020 at 1:35am
Aaaand one more from me...
https://www.youtube.com/watch?v=LHXB931PNcE Best 123 mph with tennis ball (questionable, likely 116mph) Best 106 mph with 160g rusty ball. |
Title: Re: Chronographs! Post by Mersa on May 11th, 2023 at 9:13am |
Title: Re: Chronographs! Post by IronGoober on Jul 5th, 2023 at 4:21pm
New data with a 30" Kevlar split seatbelt sling and then a 38" Kevlar sling and a 56g tennis ball.
I switched from the 30" to the 38" when I hit 61 m/s (for referencing the plot. All values are in m/s.) This is my best so far with a tennis ball. Stones always seem to go faster by about ~5 m/s or so. ![]() |
Title: Re: Chronographs! Post by joe_meadmaker on Jul 6th, 2023 at 10:43pm
I didn't total the numbers up to get an exact average, but at a glance it looks like the average speed increase (between the two slings) was in the neighborhood of 8 m/s. It would be funny if (up to a certain point) every inch of length got you another meter per second.
Incredible speeds by the way! :thumb: |
Title: Re: Chronographs! Post by IronGoober on Jul 8th, 2023 at 10:14am
That would be interesting. I could do slings every 4 inches and see how it holds up. But I really think it just comes down to the slinger for the most part. It's hard to separate the two.
Even averages session to session will vary, or depend on how warmed up (or sore, lol) I am. If you just consider max speed they aren't too far apart. My best with a 30" sling/tennis ball is 64, but it's only 68 with a 38" sling. But I guess that's why you would have to use an average and make sure the sampling was high enough that you gett a gaussian distribution (bell curve). |
Title: Re: Chronographs! Post by IronGoober on Jul 23rd, 2023 at 12:49am
From Archaic arms:
https://www.youtube.com/watch?v=kpcFYMB8Owg From Mersa: https://www.youtube.com/watch?v=ECUpWrDxMpg From Sarosh: https://www.youtube.com/watch?v=dYMfFopTcWs ![]() |
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