Welcome, Guest. Please Login
SLINGING.ORG
 
Home Help Search Login


Page Index Toggle Pages: 1
Send Topic Print
A better estimate (Read 643 times)
Mersa
Interfector Viris Spurii
*****
Offline


Druid

Posts: 2594
Australia
Gender: male
A better estimate
Dec 16th, 2017 at 12:47am
 
So up untill today my estimates for muzzle velocity were done by filming me throwing over a measured distance then counting the frames it takes to reach the target .
This method was revealed to be less accurate due to the digital roll.
So today I tryed a new method filming on slowmo with a stopwatch in frame.
This way I was able to get a time of release and a time of impact.
This seems to be more accurate to me ?
Any reason not to think this is pretty accurate method??

We also did the same for a friends bow.



Back to top
 

Razor glandes, Aim for the eyes!!!
 
IP Logged
 
johan
Funditor
****
Offline


no longer active:keep
the flame of slinging
alive

Posts: 531
Re: A better estimate
Reply #1 - Dec 16th, 2017 at 3:03am
 
i have filmed with 2 cameras one is "compact", the other dslr . dslr has 50fps but rolling shutter, compact has 30fps but no rolling shutter.
what i wanted to measure was not time over distance (e.g.30m) but "muzzle" velocity
for time over distance @20 and @30 m i get velocities of 35-44m/s depending on how hard i throw ...
thats an average.
for muzzle velocity i measured distance traveled frame by frame ~58m/s max
for more details:http://slinging.org/forum/YaBB.pl?num=1491867623/0

i don't think that the stopwatch in the frame will make measurements more accurate. any video editing program has time measuring if thats not enough then count the frames. 
Back to top
 
 
IP Logged
 
Mersa
Interfector Viris Spurii
*****
Offline


Druid

Posts: 2594
Australia
Gender: male
Re: A better estimate
Reply #2 - Dec 16th, 2017 at 3:40am
 
I think an average over 10m is still going to be close to my max speed , in both styles of measuring that I have used my average soft throw is averaging around 30m/s and my harder throws are in the 40-50m/s over 10m.
I'm slinging a 27inch sling so I think I'm doing ok if I can achieve those speeds. I wasn't sure whether the first method of reading speeds was an accurate representation but after the second method coming up with similar more accurate readings I'm more convinced that's where I'm at.

Now to break the 150m mark and finally the 200 ..... Hopefully !!
Back to top
 

Razor glandes, Aim for the eyes!!!
 
IP Logged
 
johan
Funditor
****
Offline


no longer active:keep
the flame of slinging
alive

Posts: 531
Re: A better estimate
Reply #3 - Dec 16th, 2017 at 11:01am
 
with the velocities you mention, you probably reach around 200m.
Back to top
 
 
IP Logged
 
Mersa
Interfector Viris Spurii
*****
Offline


Druid

Posts: 2594
Australia
Gender: male
Re: A better estimate
Reply #4 - Dec 16th, 2017 at 5:01pm
 
I haven't tried to throw for distance for a while now.
I set myself a goal of 200m after I first measured out my throws over 100m. All my longest throws have been with golfballs or stone so I'm hoping there is still some fine tuning I can do. Lead bipoints might give me the extra meters in chasing. But then it's finding them. If I can get 150 out of a golfballs id be pretty happy
Back to top
 

Razor glandes, Aim for the eyes!!!
 
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print
(Moderators: Morphy, Rat Man, vetryan15, joe_meadmaker, Curious Aardvark, Chris, Kick)