Now obviously a whip is very different. I wonder though if our science guys could use a similar approach to better understand sling mechanics?

https://youtu.be/AnaASTBn_K4

Yeah, I’ve watched that video about a dozen times so far, and it still fascinates me. I’m still waiting for the academic paper on this, but I don’t think it translates to slinging. That video is really focused on the transition of a knot on a whip as it breaks the sound barrier. In that respect the mechanics of a sling crack are identical but that’s has little to do with the actual slinging part.

I do have some Mocap data from a few slinging motions, but I’m missing the speed of the ball, because it didn’t have a reflective marker.

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NooneOfConsequence wrote on Oct 16^th, 2019 at 8:15pm:

I do have some Mocap data from a few slinging motions, but I’m missing the speed of the ball, because it didn’t have a reflective marker.

(With the danger of repeating your thoughts ::) )
There should be a synchronized, timestamped video recording available for this MOCAP?
Two options:
a) Requirement: video from several known positions.
rewrite the code to do pattern recognition of the video to do triangulation onto the ball.
appropriate color channel separation, edge detection and centroiding should give a decent result for marker position for each camera channel. Then feed it as an additional marker point to the triangulation routine of the software. But I'm not sure if you have that deep access to the software  ::).

b) Requirement: video feed from single position with timestamp.
get the release time. approximate ball speed =  pouch speed at release time. This will yield an upper limit for the ball speed.

Cool byzantine capture :-)

did you do any other styles ?

I am not technology inclined,  but what is Mocap? That is sweet. I vaguely remember seeing something liliklilike this before.

vetryan15 wrote on Oct 17^th, 2019 at 6:55am:

what is Mocap?

Motion capture. The tracking of movement in space. This allows to create a "digital image" of some real-world action in your computer and then do analysis and further processing on it (e.g. animations in films and computer games).

https://en.wikipedia.org/wiki/Motion_capture

Curious Aardvark wrote on Oct 17^th, 2019 at 6:28am:

Cool byzantine capture :-) did you do any other styles ?

If I could do it again today, I would have better form, but here are the other variations.
I was also confined to an enclosed lab and was only allowed to throw a very lightweight plastic ball.

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Ok CP... I’ve been thinking about this, and I think I wanna was wrong when I said it doesn’t relate to slinging. The whip crack starts as a traveling wave, and heavier whip handles mean there is more momentum and thus it’s easier to get a good crack. There is a similar transfer of momentum from the ammo in the pouch to the pouch and release cord as the pouch is opening. I’ve noticed that heavy ammo tends to crack better... probably for the same reason that heavy whips crack easily.

NooneOfConsequence wrote on Oct 21^st, 2019 at 11:34am:

Ok CP... I’ve been thinking about this, and I think I wanna was wrong when I said it doesn’t relate to slinging. The whip crack starts as a traveling wave, and heavier whip handles mean there is more momentum and thus it’s easier to get a good crack. There is a similar transfer of momentum from the ammo in the pouch to the pouch and release cord as the pouch is opening. I’ve noticed that heavy ammo tends to crack better... probably for the same reason that heavy whips crack easily.

I've found this too. It still depends a lot on the whip but the extra momentum the larger ammo brings helps with cracking. Whether that really means a faster release/positive effect of the "performance" of the sling, I'm not sure. Cracking a whip and slinging are related but I'm not sure how closely.

I figured, I thought it was something like that, but I just didn’t have the scientific vocabulary or the know-how to express it.