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Thread: [WRC] Tour de Corse 2019
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20th March 2019, 15:19 #31
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20th March 2019, 15:26 #32
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you can't attach camera to the helmet, you can't glue to helmet any camera holder (by normal glue, 3M tape, etc.) it's simply like that, G-forces play here big role also I believe
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20th March 2019, 16:11 #33
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The peak G-force during a crash can reach well over 100G (per time period of milliseconds or even less). GoPro weights around 0,1 kg which means at the peak acceleration the force reaches over 100N (>10 kg). This is an additional force to what your spine and muscles (with the help of HANS) have to keep in place. It's clear that ideally the weight of anything attached to your head including helmet shall be the lowest possible.
Than there is a risk that the camera gets released in an accident or due to long-term vibrations and shocks in harsh environment in terms of temperature, humidity or dust and flies like a projectile in the car.
And last but not least the camera alone can penetrate the helmet if the helmet with the camera mounted on it hits the rollcage/roof or whatever.
I would personally never wear it.Stupid is as stupid does. Forrest Gump
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20th March 2019, 20:53 #34
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how plastic can penetrate kevlar is something that puzzles the scientists to this day...
Can't the dashboard/rollcage mounted cameras act as projectiles ?
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20th March 2019, 23:09 #35
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Ask yourself whether the screws, lens, acumulator or PCB will easier brake through the rollcage tube or the helmet in the moment when they find themselves in between.
Sure. That's why they are being checked by scrutineers whether they conform with safety requirements.Stupid is as stupid does. Forrest Gump
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20th March 2019, 23:21 #36
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Its a camera not a cluster grenade... once the things you mention hit the first object which most likely will be the windscreen or another part of the car the lost energy will be more than enough to render them incapable of doing any damage, and at the end of the day its 2019 i am sure it will take less than a month for engineers to develop a casing for a camera that will be safe, at the end of the day have a small elastic cord attached to a solid part of the car so in case of impact the movement of the camera is limited...
and have the scrutineers inspect these cameras as well...
its beyond stupid to discuss weather or not a camera weighing less than 200gr to be a hazard in a motorsport that involves driving at 200kph among trees...
I am sure if those useless blobs of fat over at the promotion of the WRC had the energy and the will to move the sport further they could figure something out instead of the joke angles we get today.
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21st March 2019, 08:16 #37
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Braking a helmet by hitting a rollcage is not that unusual (for example here: https://www.ewrc.cz/images/2009/suma...jf-crash-4.jpg ). If a camera is present on the helmet in such accident it's likely that some of it's parts penetrate into the helmet and you don't want to have metal joint or screws being pushed in your helmet by the rollcage. Moreover hitting a rollcage with the camera is far more probable than without simply because the camera takes some of the space between the helmet and the rollcage.
Massa's helmet was penetrated by 700 grams heavy spring being hit @ 250 km/h which ricocheted, i.e. only part of the energy was spent on the actual penetration. In case of a helmet hitting the rollcage what is moving is the whole head with the helmet and the camera together, i.e. the moving mass has roughly 6,5 kg which means that it doesn't need so high speed for similar effect (6,5 kg heavy head @ 82 km/h has the same energy as 700 grams heavy thing @ 250 km/h). The speed in which the helmet can hit the rollcage is hard to estimate but it can get close to the vehicle speed at the moment of the crash, i.e. it is not a magnitude lower than in Massa's case.
For your information a 200 grams heavy thing @ 200 km/h has a 3/4 energy of a 9 mm bullet and 1/2 more than a 0.32 ACP bullet (Škorpion submachine gun for example). That is not negligible at all like you imply.
Anyway any added weight on the head makes the risk of injury or even death higher. That's a fact hence why it's a bad idea to have a camera on the helmet no matter how well it is fixed. If there is a need for camera on the helmet than it shall be as light as possible, as small as possible and fixed on a helmet which is actually tested together with the camera.Last edited by Mirek; 21st March 2019 at 08:24.
Stupid is as stupid does. Forrest Gump
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21st March 2019, 09:04 #38
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It´s probably not the helmet hitting the rollcage. It´s the rollcage hitting the helmet. A camera made of mostly plastics seems not to be the problem when the rollcage coming with loads of G after a heavy impact.
Cameras or not - this is thread of Tour de Corse, not technical thread.
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21st March 2019, 09:11 #39
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Sorry for off topic but You are wrong. It's the head of the occupant which keeps moving after the bodyshell/rollcage already hits the obstacle (tree, wall or whatever). This is the very basic foundation of passive safety topic. And the camera of course is a problem.
Vague talk like "loads of G" is completely useless. What do You know about them? Is 10 G peak dangerous if You fall down on the ground on Your head? Tell me.Last edited by Mirek; 21st March 2019 at 09:30.
Stupid is as stupid does. Forrest Gump
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21st March 2019, 09:30 #40
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if you crash a rally car at 200km/hr on a solid object you are going to die no matter if the camera is present in the car or not... how many corners at 200 km/hr does the whole wrc have ?
a go pro hero 7 weighs IN TOTAL 116 grams... can you name a METAL component in that camera that can penetrate a helmet ? most screws in there are 1mm maximum... how can a screw weighing 0.1grams and 1mm wide penetrate a helmet ? most of the weight is the plastic casing and the copper in the circuits...
comparing the energy of bullets what fly at a straight line with the forces developed in a car crash and are in multiple directions almost at the same time is beyond stupid...
i wonder why people put cameras on their helmets during testing videos...Last edited by N.O.T; 21st March 2019 at 09:42.
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