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  1. #201
    Legend minimoke's Avatar
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    Quote Originally Posted by Rocketman View Post
    Just had it clarified - the target parachute deployment time is 1.1 secs (fully deployed and inflated) from event with automatic electronic firing of rocket. From a hover you will fall less than 6 metres in that time, and it takes only 2 more metres to slow down to the parachute descent rate. So if they can achieve this then 8m is enough. They also say they are designing other safety features to take a 10m fall.
    The physics and forces involved to get a free fall arrested in 1.1 seconds and 10m are way beyond my comprehension! 1.1 seconds - they are having you on surely? Is there any system in the world that comes even comparibly close?

    US navy fight jet ejector seats take over 4 seconds and I have no idea how much money they would have invested in that technology.

    You might find there is a lot more money to be made in the safety systems than in the jetpack!

    Or imagine the military application. You'd be able to drop paratroopers over enemy lines and the could free fall to 10m deploy the chute and land before anyone know it

    The technology to recognise an engine failure, blast out a chute and get the chute inflated in less than 1.2 seconds must surely be a world first. Have they given you any idea how long they expect to perfect this technology - or is it an idea with another 30 years worth of development.

    But I suspect there will be justification and the money for flying paramedic response in other cities of the world. Even motorbikes can't take the crows route to emergency events. And maybe a medical insurer will diferentiate its product with guaranteed response times enabled by flying paramedics - you buy the insurance to get the service.
    I think you missed my point. That you can create a device to fly paramedics is one thing. To actually get paramedics to fly it is quite a different proposition. The desire to save life does not ordinarily go hand-in-hand to significantly risk ones own life!

  2. #202
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    Quote Originally Posted by Nevl View Post
    Scouting, recon, Aerial surveillance. Coordination.
    Everyone seems to be heading towards UAV these days, instead of a single guy doing it, there could be a few of them from the safety of a room. Hi-Def communications these days have come along way, you can now buy hi-def wireless links and its good for flying hobby r/c planes. Plus they have things like FLIR infrad that would be more valuable and a vulnerable pilot.

    I think that this jetpack is a solution to a unknown problem. Is there not confusion on what applications these are for?

    On a side note I think that quadrotor helicopters would have vast more applications. They are highly maneuverable and mechanically speaking they require only 4 motors, unlike with a jetpack which required rudders, controls sticks, its still a mechanical problem with constraints for user safety.
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  3. #203
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    Quote Originally Posted by minimoke View Post
    The physics and forces involved to get a free fall arrested in 1.1 seconds and 10m are way beyond my comprehension! 1.1 seconds - they are having you on surely? Is there any system in the world that comes even comparibly close?
    Try airbags - from Wikipedia:

    The design is conceptually simple; a central "Airbag control unit"[25] (ACU) (a specific type of ECU) monitors a number of related sensors within the vehicle, including accelerometers, impact sensors, side (door) pressure sensors,[26] wheel speed sensors, gyroscopes, brake pressure sensors, and seat occupancy sensors. When the requisite 'threshold' has been reached or exceeded, the airbag control unit will trigger the ignition of a gas generator propellant to rapidly inflate a nylon fabric bag.....

    .....Typically, the decision to deploy an airbag in a frontal crash is made within 15 to 30 milliseconds after the onset of the crash, and both the driver and passenger airbags are fully inflated within approximately 60-80 milliseconds after the first moment of vehicle contact.


    So airbag is 0.06 seconds fully inflated after event. I see no reason a rocket propelled parachute with airbag inflating outer ring could not be out in 20 times this figure (1.2 seconds from accelerometers detecting free fall)

  4. #204
    Legend minimoke's Avatar
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    Quote Originally Posted by Rocketman View Post
    Try airbags - from Wikipedia:

    The design is conceptually simple; a central "Airbag control unit"[25] (ACU) (a specific type of ECU) monitors a number of related sensors within the vehicle, including accelerometers, impact sensors, side (door) pressure sensors,[26] wheel speed sensors, gyroscopes, brake pressure sensors, and seat occupancy sensors. When the requisite 'threshold' has been reached or exceeded, the airbag control unit will trigger the ignition of a gas generator propellant to rapidly inflate a nylon fabric bag.....

    .....Typically, the decision to deploy an airbag in a frontal crash is made within 15 to 30 milliseconds after the onset of the crash, and both the driver and passenger airbags are fully inflated within approximately 60-80 milliseconds after the first moment of vehicle contact.


    So airbag is 0.06 seconds fully inflated after event. I see no reason a rocket propelled parachute with airbag inflating outer ring could not be out in 20 times this figure (1.2 seconds from accelerometers detecting free fall)
    I've noted a key device in air bags is the Impact Sensor. So, if I've got this right Martin are going to invent essentially a huge donut which will self inflate similar to an airbag. This will blow the sides of the chute out and allow it to be immediately filled with air enabling the gentle descent of the pilot with brown pants. Your idea might be quite feasible - have you any clues that anyone has come close to achieving such a device.

  5. #205
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    Quote Originally Posted by minimoke View Post
    I've noted a key device in air bags is the Impact Sensor. So, if I've got this right Martin are going to invent essentially a huge donut which will self inflate similar to an airbag. This will blow the sides of the chute out and allow it to be immediately filled with air enabling the gentle descent of the pilot with brown pants. Your idea might be quite feasible - have you any clues that anyone has come close to achieving such a device.
    I wouldn't think it would be too hard. It is all about setting the right parametre so it doesn't go off accidentally. It might include rev meter (drops below a certain amount), altimetre (rate of decent), gyroscope (lean is great than expected - ie. one engine down, or rate of spin indicates out of control), fuel meter (out of fuel), distance sensor (when combined with rate of decline might indicate problems).

    There are others you could add in (ie. smoke sensor) but it may actually be better for it not to deploy as the pilot might be able to land even in there is an issue (I know helecoptersc can autorotate(?) and land even if the engine dies)), or just that you have a stunt pilot pushing the boundaries (ie a fast swoop to the ground that would look pretty darn cool, the system may think is a probably crash landing and ruin the look).
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  6. #206
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    Quote Originally Posted by CJ View Post
    I wouldn't think it would be too hard.
    If its not so hard where is there a working example. The concept seems ideal for military, adventurer parachuting, space craft recovery, dragster (Car and boat) type applications - indeed anywhere there is a parachute that is used. So we are now looking at a Jet pack carrying a pilot, a parachute and a inflating donut that has to be, what, 25 metres round? Sounds like you are packing a fair bit of gear onto the jetpack. Backers of the IPO are, I reckon, backing more garage tinkering - this time on parachutes!

  7. #207
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    Quote Originally Posted by minimoke View Post
    If its not so hard where is there a working example. The concept seems ideal for military, adventurer parachuting, space craft recovery, dragster (Car and boat) type applications - indeed anywhere there is a parachute that is used. So we are now looking at a Jet pack carrying a pilot, a parachute and a inflating donut that has to be, what, 25 metres round? Sounds like you are packing a fair bit of gear onto the jetpack. Backers of the IPO are, I reckon, backing more garage tinkering - this time on parachutes!
    Cars already preload teh brekes if an accident is sensored. Some even apply them lightly and the technology (but not public acceptance) is there for the car to brakes to be fully deployed (but imagine if you got a false postive on the motorway with ABS brakes deployed and no way to overrid them!!!).

    And I dont think the jet pack investment will be a flyier - I just feel sory for Rocketman who continually jumps into the ring with Tyson and gets pummelled each time.
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  8. #208
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    Quote Originally Posted by CJ View Post
    Cars already preload teh brekes if an accident is sensored. Some even apply them lightly and the technology (but not public acceptance) is there for the car to brakes to be fully deployed (but imagine if you got a false postive on the motorway with ABS brakes deployed and no way to overrid them!!!).

    And I dont think the jet pack investment will be a flyier - I just feel sory for Rocketman who continually jumps into the ring with Tyson and gets pummelled each time.

    Actually Rocketman has shot down every single one of Mini's arguments. He is getting so desperate that he is inventing ever more implausable needs to back up his equipment. If we follow Minis logic you would never be allowed to drive a car or fly in an airplane unless every single passenger had their own self inflating parachute. He is setting the bar for the jetpack on a way higher level than airplanes that have to fly 100's of people at a time.

  9. #209
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    Quote Originally Posted by Nevl View Post
    Actually Rocketman has shot down every single one of Mini's arguments.
    He is certainly able to come up with all the answers. However converting answers to a product that you can manufacture for a reasonable price, sell to a market that wants it and can find people actually prepared to fly it in the numbers required to turn a profit is another matter.

    Referencing technology developed in motor cars, for example, is all well and good but lets reflect on the many years it has taken to evolve this technology - which is on the back of sales volumes.

    The development, testing and certification of this unique parachute system in a JetPack application must surely going to cost truck loads of loot. Or am I just a bit nuts to think that Martin can't do it in a commercially viable way.

  10. #210
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    Quote Originally Posted by Nevl View Post
    Actually Rocketman has shot down every single one of Mini's arguments. He is getting so desperate that he is inventing ever more implausable needs to back up his equipment. If we follow Minis logic you would never be allowed to drive a car or fly in an airplane unless every single passenger had their own self inflating parachute. He is setting the bar for the jetpack on a way higher level than airplanes that have to fly 100's of people at a time.
    Rocketman has very calmly shot down Minis arguments.

    It is not something that I would invest in, however I am not going "bag" on anyone wanting to have a go. I hope it is a success for Martin Jet Pack and they seem to have captured a lot of interest from overseas.

    This country needs more people like Martin to give it a go instead of the continual knockers sitting on the sideline coming up with all the reasons in the world why XYZ wont work, cant work, stupid idea etc.

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