Measuring Drive Speed

[TheBeardedFatGuy]

Yes it is simple if you have a ridiculous camera. I did this quickly and used a couple of internet conversions, and am not being stringent with significant figures (pretty irrelevant when you see the result), but it's probably still correct:

A 60MPH throw is roughly 2685 cm/s
An average disc diameter is 21.5 cm
It would take a 60MPH throw only 0.00801 seconds to travel 21.5 cm
A 240 frame per second camera would shoot one frame for every 0.00417 seconds

This means approximately two frames for the disc to travel its diameter, at this high framerate.

A 59MPH throw travels 2637 cm/s.
This throw would take 0.00815 seconds to travel the same 21.5 cm
The difference between these two throws (59 vs 60 MPH) is 0.00014 seconds over this distance
To judge the difference between 1MPH at this velocity, you would need a camera that can shoot roughly 7,000 frames per second.

I'd say just set up some posts or indicators a decent distance apart.

That would work, but you'd run up against trying to judge where in the frames the disc hits its marks. Odds are you'd catch the disc anywhere but right when it hits the marks you're using to measure. At least if you measure distance traveled relative to the diameter of the disc as I described you're not stuck hoping your disc is hitting a mark at the exact moment the frame rate ticks. There's no reason you couldn't extend your measurement over more than two frames, other than the fact that disc movement is only truly perpendicular to camera angle in one position, though you can fake it over a relatively short distance. You can pull the camera back to prolong 'perpendicular' flight in frame, but you'd sacrifice fine measurement. Plus the disc is slowing from the moment it is no longer being propelled by your hand. Over 2,000 years ago Eratosthenes correctly measured the circumference of the earth with simple observation and math. I can't help but feel we're missing some simple solution to this problem.

 

[DiscJunkie]

I can't help but feel we're missing some simple solution to this problem.

The disc should be measured as close to release as possible. It will begin to lose speed immediately after release. The longer your distance between reference points, the more the speed will deteriorate during the measurement.

The simple solution seems like a radar gun behind a net.
It may not be the cheapest solution, but it is fairly simple.

 

[ILUVSMGS18]

Seems like befriending a cop is the easiest way to solve this issue, well that and a batting cage.

 

[runningDoc]

The disc should be measured as close to release as possible. It will begin to lose speed immediately after release. The longer your distance between reference points, the more the speed will deteriorate during the measurement.

The simple solution seems like a radar gun behind a net.
It may not be the cheapest solution, but it is fairly simple.

Brand new radar gun on amazon is around $70.... super high speed camera probably in the thousands.



What I want to see is innova get 30-50 different pros throwing a aviar, roc, teebird, destroyer to benchmark distances and averaging the arm speed required to throw an aviar 250, 300ft, 350ft.

Then a roc 250, 300, 350, 375, 400ft. Same with destroyer teebird etc. maybe do this inside a indoor stadium/controlled environment.

With a big enough sample size you could start getting general data on arm speed required to throw specific discs certain distances.

It may seem obvious that you need 60+mph arm speed to throw a destroyer 400+ft but to get actual baseline numbers could be really useful in gauging your arm speed.

So if the average of 50pros have a 60mph arm speed when throwing a roc 375ft and you can throw a roc 375ft then you know you've got around 60mph arm speed

 

[slowplastic]

I'd love some data on pro release speeds and distances like that. Not like that one random chart that exists from some tournament on one hole.

I definitely agree that the likelihood of the disc hitting the set pole intervals perfectly on both ends is very very low. Having a few markers on them (like +/- ~1" for a few inches) would then allow for the disc to accurately hit some marker, most likely. It's possible to set this up for sure. But, radar gun is the best option...there's got to be one that's reasonably affordable out there that works ok.

 

[RonTheWhip]

While I'd be curious to see the sample data from measuring a bunch of pro arm speeds it wouldn't be much help to anyone trying to learn about the relationship between speed and distance. There are too many other variables that determine why a disc flies as far as it does. Suffice to say higher speed = more distance.

When I got to throw in front of a radar gun I was surprised to learn the consistency in speed of what I considered my "standard full throw". 65 mph every time over 10 throws or so. Most amateur arm speeds I would guess fall in the 45 to 55 mph range with pros in the 55 to 65 range. Each arm is different though and it would be cool to see a statistical spread of arm speeds.

 

[TheBeardedFatGuy]

I wonder how accurate the automatic speed detectors they set up by the side of the road are. You'd probably get your ass in trouble, but you could set up a net, like maybe a portable soccer goal, and huck a few discs right at this. Also don't know if it would register something as small as a disc edge-on. Probably not.

http://www.dgcoursereview.com/forums/attachment.php?attachmentid=60382&stc=1&d=1481212419

 

[Putt for D'oh]

... a batting cage.

probably this. Find a guy that gives pitching instruction in the area. I know a few that use the local batting cages, good chance one of them has a radar gun. Maybe a high school coach. might be a chance it sounds like something fun to them to see.

 

[Shamis]

I wonder how accurate the automatic speed detectors they set up by the side of the road are. You'd probably get your ass in trouble, but you could set up a net, like maybe a portable soccer goal, and huck a few discs right at this. Also don't know if it would register something as small as a disc edge-on. Probably not.

http://www.dgcoursereview.com/forums/attachment.php?attachmentid=60382&stc=1&d=1481212419

lol, I'm totally pulling over the next time I see one of these damn signs and throwing all my discs at it.

 

[slowplastic]

I just want to reiterate, as RonTheWhip also found...that velocity is surprisingly consistent for each person, from throw to throw (considering they have played enough to have a regular throwing form). Again I don't think knowing MPH is super useful for relating to what "disc speed" someone can throw, but it's very interesting as a teaching tool. Especially learning that trying to throw 20% harder than "normal" often doesn't increase your velocity at all!

I would love to see a pro or two do something like throw a putter in 25' intervals from ~225' to ~350', and a mid like a Roc in intervals from ~250' to ~400' or wherever they max out. It would be very interesting to see how much extra velocity per distance is needed for discs like these, and I bet in this class of disc it would be very consistent from player to player (considering they are high level players).

I think with some drivers it can be weird, especially with AM's. I remember at one point I was maxing out ~325' and I got my hands on a Vulcan...instantly threw it ~380' several times. Then I cleaned up my form and I lost all that extra distance. Turns out with drivers there can be some weird balance of torque and stability that can give people more distance than they "should" have with their velocity...some people find this weird balance with a couple of discs and it works perfect for them (but it's not long term improvement/a way to throw that far with all discs). So with mid-level players throwing drivers I would imagine the data could be potentially more messy.

As far as pro's with drivers of their choice...a pro without a massive arm throwing a 400' shot would likely throw a less stable disc and it would have a lower speed than say Simon or Eagle throwing a PD2 400' and crushing it to counter the stability factor. So a 400' shot from pro to pro with different drivers I think could have a reasonably big velocity spread depending on if it's a max D shot or a control overstable shot for them...which is why I'd love to see mid/putter data instead/as well. (It may take 60MPH to throw a Tern 400', but 65-70+ to throw a PD2 400'...I'm just guessing as best I can for an example)

 

[Consult20]

I have one I use for airguns.

Lighting is critical and it has to be the right kind. No fluorescent, e.g.

I don't know anybody who hasn't eventually shot theirs including me. Sometimes you get lucky and just dent something nonimportant.

I guess you could put it in a stout wooden box, something like a heavy footlocker.

These have two sensors and time the light interruption across them.

A disc might be 7 inches across at the center and one inch across at the edge, so would you have to throw straight and right over the middle? Not sure.

I never shot mine but I could see it happening, you would absolutely want to protect it from a disc hitting it. And yes you are correct with how they work, outdoor lighting and throw so the disc goes over the two sensors. It shouldn't be too hard to hit the sweet spot if you set it up fairly close.

I'd set it up with a sheet or something behind it to catch the discs. And yes, set the chrono behind something to protect it, and mark the sweet spot area you need to throw over. It should work great, and then convert FPS to MPH (5,280 feet in a mile, 3,600 seconds in an hour).

So if you throw 100FPS that would = 68.18MPH (100 x 3600 / 5280)

Let us know if you try it, thanks.

 

[Consult20]

While I'd be curious to see the sample data from measuring a bunch of pro arm speeds it wouldn't be much help to anyone trying to learn about the relationship between speed and distance. There are too many other variables that determine why a disc flies as far as it does. Suffice to say higher speed = more distance.

When I got to throw in front of a radar gun I was surprised to learn the consistency in speed of what I considered my "standard full throw". 65 mph every time over 10 throws or so. Most amateur arm speeds I would guess fall in the 45 to 55 mph range with pros in the 55 to 65 range. Each arm is different though and it would be cool to see a statistical spread of arm speeds.

Here's a thread from earlier this year when Simon threw 103MPH on a radar gun.

http://www.dgcoursereview.com/forums/showthread.php?t=121482

 

[TheBeardedFatGuy]

Seems like befriending a cop is the easiest way to solve this issue, well that and a batting cage.

Police departments are always looking for community outreach opportunities. Any organized DG club might be able to arrange an event where the cops would be present for a couple hours to use their radar gun. Besides, it would be funny to watch the reaction of the doobage crowd when the men in blue show up at the course.

 

[Nick481]

http://physlets.org/tracker/

 

[Nick481]

I bet if you had police on hand a lidar gun may work even better than a radar gun. It uses laser and gives a near instant read out.

 

[Dr.Smooth]

hazy shade in dayton has one I believe, might want to talk your local retailer in to getting one.

good way to say yeah your arm speed would warrant you using these types of drivers for example

 

[DamonRipper]

I have a chronograph and set it up and it did work fine for discs, although the lighting is tricky as previously mentioned. You need sunlight, but not too bright or direct or it won't pick up. I did it on a semi-overcast day with good results. I hung a blanket from the garage door to catch the discs. I was most worried about smashing the chronograph with a disc, so I ended up putting it on a tripod and behind a large trash can that was just taller than the top of the chrono. If I released low it would just skip off the trash can