Topic: Wii Strap Break Test

[NeoThunder]

Ok, So after getting my new straps from Nintendo, I decided to sit down and do my own bench test to my old Wii strap to determine just how much force it takes to break a Wii Strap.

First of all it's important to tell all incase they don't know is that   Force=Mass*Velocity
by scientific standards Force is measured in Newtons, Mass is measured in Kilograms, and Velocity is measured in Meter's per second.  I will be referring back to this eqation a lot.

Of course since I only had one strap I could really only do one test.  So my test was symple and to the point, determine with gravity pulling on a set amount of mass, how much weight it would take to break the strap so I used empty milk jugs, and after filling 3 (24 pounds) the strap still was not broke, so i had to go find another and strap it to the mess I had already set up.  I tell you this only to let you know that the strap set with 24 pounds of weight on it for awhile, I would say 10 min, before adding a final 4 pounds that ended up breaking the strap.

So, 28 Pounds of weight to break the strap.

however, we all know our Wiimote's don't weight that much.  I infact never weighed mine but I guessed that it weighed about 1/2 pound (with batteries of course), so to get the strap to break you have to add velocity.  I figured that the average person could throw a baseball at 75 mph.  For arguement, lets just say they can throw at 100 mph, which is about 44.7 meter's per second. So that means .227 kilograms(about Wiimote Weight) multiplied by 44.7 meter's per second equals 10.1469 newtons.  How much force is that? 2.281 pounds of force

So, thrown at 100 mph, when let go, there is 2.281 pounds of force acting on the Wiimote strap.

So why are straps breaking?....We know that it takes 28 pounds to break a strap (which is 124.55 Newtons of force) and at 100 mph, there is only about 10 newtons acting on the strap.  But people seem to claim that it broke while throwing them,  Well I got great news, cause it seems these people have some really good arms

Which brings me to my last point, since it takes 28 pds (12.7 Kg) of force, which comes out to 124.55 newtons, and a Wiimote only weights .227 Kg.  By dividing 124.55 by .227 that comes out to 549.182 meter's per second of speed that a Wiimote is flying out of someone's hand.  Ohh, and incase your wondering, thats about 245.5 mph.  YES, these people are throwing Wiimotes 2 and 1/2 times the speed pro-baseball players throw at.

So what does this mean?  Well, I think it's pretty simple.  Any person that tries to say they weren't doing anything too wild when the Wiimote flew out of their hands and the strap broke is...well, LIEING, Or not telling the entire truth.  All these cases i've heard of are clear that people wern't using the strap, lost their grip, got mad, took strap in hand, and snapped it, then said it's Nintendo's fault.  Ohh ya, another thing.  That Wiimote wouldn't go threw a wall if the strap snapped cause there is this thing called "deflection".  Meaning that some or most of the energy would be lost when the strap snapped causing it's speed, or energy, to be slowed, and because of this it's tragetory would probley not travel where you aimed it.

Finally, I'm willing to admit some of my figures could be wrong, so if anyone wants to correct me, please feel free.

[UncleBob]

Here's the problem with your theory...

Firstly, you're assuming that all straps are made exactly alike.  It's always possible that somewhere along the way, some straps were made that had minor flaws in them - and thus they would require less force to break.

Secondly, I'm assuming you haven't swung your Wii Remote around a lot.  Perhaps repeated uses can weaken the strap.

To really do this the MythBusters way, you'd need to test more straps (I'd say at least 50 - 100) and you'd need to test them in a way that you'd be constantly adding and removing the force, or, if you will, "jerking the strap".  Try putting about two pounds at the end of the strap, then bob it up and down like a yo-yo some amount of time.  See if that makes a difference.

[NeoThunder]

my point was addressing all straps, not ones with defects and astablishing that it takes a great amount of force to break a strap...a normal strap, not one thats been uncared for, or one thats been roughed up.  It's not Nintendo's fault if you rough up your strap and don't replace it.

Why don't you do a test and show your evidence to counter my claim.

I think my test was as controlled as I could with only one strap at my disposole

[jasonditz]

You're using the wrong equation: force doesn't equal mass times velocity, it equals mass times acceleration. A newton is a kg * meter / s^2

Remember also that the 124.55 is an ideal maximum, as from the sound of your experiment you placed the load more or less equally over both sides of the strap. That would mean either side of the strap could handle about half that force individually, or 62.275 N.

What's really happening here is a transfer of momentum from your arm to the wiimote. To calculate a precise minimum velocity needed to break a Wiimote strap, we would need some information about the strap's elasticity. While it's difficult to say for certain with the information given, keeping in mind that the strap is basically constructed of 14 pound test material it is not difficult to perceive of a healthy adult arm's momentum transfer producing a force sufficient to break the strap.

Remember:

mv = F delta t

[UncleBob]

Quote
Originally posted by: NeoThunder
my point was addressing all straps, not ones with defects and astablishing that it takes a great amount of force to break a strap...a normal strap, not one thats been uncared for, or one thats been roughed up.  It's not Nintendo's fault if you rough up your strap and don't replace it.

Why don't you do a test and show your evidence to counter my claim.

I think my test was as controlled as I could with only one strap at my disposole

Oh no, I don't dispute your claim at all.  The thing is, it isn't really helpful (however, as far as the physics and math part of it all, y'all can debate that out as much as you want... I don't have a clue).  I'm just saying that if all the straps but one are made perfect and can withhold 1,000 pounds of pressure, but one of them has a flaw that sends it flying into (and through) the television, then the whole idea that someone is abusing their controllers goes out the window.

However, none of this addresses the fact that the user isn't supposed to let go of the controller in the first place.

[NeoThunder]

well, since i was thinking velocity instead of acceleration, my numbers might be wrong then.  Even though I would like to think i'm at least close to being correct.  So my question is, how much acceleration or velocity is required to apply 28 pds to a Wii strap with 1/2 pd on the end of it?

[RiskyChris]

Hanging a weight off the remote strap free in the vertical axis would exert an accelleration of g, 9.8 m/s/s.

[oohhboy]

The equation he should use was F=m(v^2/R). The (v^2/R) part comes from a=v^2/R. Combined with F=ma produces the first mentioned equation.

The first numbers used were abit too high. An average person is only going to throw about 25 meters per second. That is alittle under 100 Kph. But since this is science everything will be done in S.I. No imperial units please.

F=m(v^2/R)

m=0.25 Mass of wiimote
v= 25 mps
R= .75 Radius of circle, ei lenght of my arm

F=208.33 Newtons

Force applied to strap in a static situation. F=ma

m = 14 Kg
a = 9.8 Gravational constant

F= 137.2 Newtons

As you can see, the forces involed in an average swing does excced the static load that the strap can bear. But materials have different breaking points depending on how the force is applied. When the wiimote is swung the load on the strap is dynamic and short. There is no way that during the entire throw that it is exposed to that much stress. The above only represents peak load during a dynamic event. 137.2 Newtons is the maxium it can hold if you were to hang some thing off it indefinately. Although at that poiny material deformation would change how much weight it can bear as the strap would deform pernamently via streatching. When swung the strap, like a rubber band should revert back to it's original form since the amount of total energy is probaly not enough to cause lasting deformation.

Never the less given enough throws over time, especially over short periods of time, the strap would deform, and eventally break from stress fractures.

Hence the almost doubling of the strap width. It should tolerate atleast 3 times more force than before, signifancly above an average throw and problay at the limit of the human body.

In conculsion, the strap was too weak even though it could bear the stress over limited durations and time.

[Caliban]

Quote
Originally posted by: UncleBob
To really do this the MythBusters way...

Ahem, someone please email MythBusters to test this out, with some cooperation with Nintendo I think this would be great publicity and we could have a "Busted" myth to clearly show that some people are just over-playing the remote.

[ryancoke]

That would be sooo awesome if a strap test ended up on mythbusters. I think it would be very beneficial to both Nintendo and the Mythbusters show.  I think in order to have an accurate test thew would need to test 50 to 100 straps and average out the force required to break them.

[couchmonkey]

Quote
Originally posted by: UncleBob
Here's the problem with your theory...

Firstly, you're assuming that all straps are made exactly alike.  It's always possible that somewhere along the way, some straps were made that had minor flaws in them - and thus they would require less force to break.

Secondly, I'm assuming you haven't swung your Wii Remote around a lot.  Perhaps repeated uses can weaken the strap.

To really do this the MythBusters way, you'd need to test more straps (I'd say at least 50 - 100) and you'd need to test them in a way that you'd be constantly adding and removing the force, or, if you will, "jerking the strap".  Try putting about two pounds at the end of the strap, then bob it up and down like a yo-yo some amount of time.  See if that makes a difference.

I've never seen Mythbusters put in that much effort.  Maybe they do put in that much behind the scenes, and they'd definitely test more than one, and probably take into account some of the arguments jasonditz made, but it's not really the most thorough science show around.  It is pretty darn entertaining though.

Edit: For the sake of argument, there's also wear and tear to consider.  Constant, heavy use of the Wiimote probably results in fraying of the strap due to friction.  I wouldn't be surprised if some of the people with breaking straps were doing silly things like swinging the remote by the strap to toss cows or literally flinging the remote and letting the strap hold it in place when pitching baseballs.

[NeoThunder]

The Wiimote myth has already been submitted to mythbuster's, by me and many others.  So we'll see if they take it up.

[UncleBob]

Quote
Originally posted by: couchmonkey
Edit: For the sake of argument, there's also wear and tear to consider.  Constant, heavy use of the Wiimote probably results in fraying of the strap due to friction.  I wouldn't be surprised if some of the people with breaking straps were doing silly things like swinging the remote by the strap to toss cows or literally flinging the remote and letting the strap hold it in place when pitching baseballs.

I said that...

[jasonditz]

The thing is, sure, you're not supposed to throw your wiimote. But if you never threw your wiimote, you'd never need the strap either. The strap's only value is in the case where the wiimote leaves the user's hand.

It's simpler for Nintendo to just use a stronger strap, after all what's it going to cost them, a few cents per unit?  

[Smash_Brother]

I'd love it if the Mythbusters tackled this...

[couchmonkey]

Quote
Originally posted by: UncleBob

I said that...

Sorry, must have been skimming!  Yeah, it would be cool if Myth Busters looked at this one.

[vherub]

It was my understanding it wasn't just about breaking, but the slightly thicker strap was less likely to loosen and slide off during a gaming sessions.
I thought this whole letting go of the controller was nonsense- until I was playing a particularly intense bought of wiisports tennis and my perspiring hand lost the grip during a forehand smash. The remote went crashing into the wall, bounced off, striking a dresser and then sliding across a barewood floor. I thought for sure it would be busted (and wiimotes are out of stock everywhere) or at least the battery cover and batteries would have come off. But it was unscathed, not even a scratch.
And I'd won the point.

[SixthAngel]

I am pretty positive it had absolutely nothing to do with remotes slipping off becaue the new thicker part doesn't even touch your wrist.

[oohhboy]

Quote
549.182 meter's per second

On another note I wish I could throw anything at 1.5 times the speed of sound. Imagine the party games you can have with that.