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Trip's g-LOC simulator project (for G-seat)

Discussion in 'DIY Motion Simulator Projects' started by Trip Rodriguez, Apr 1, 2020.

  1. Trip Rodriguez

    Trip Rodriguez VR Pilot

    Joined:
    May 8, 2016
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    Lake Ariel, Pennsylvania
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    My Motion Simulator:
    6DOF
    Hey guys! I imagine some of you have noticed my inactivity the past couple of weeks. I've had an uptick in personal responsibilities but I also got distracted by another side project.

    I've already mentioned that when I read Seattime's thread and saw the part where he mentioned having to back off on his turn in the F-18 for fear of cracking a rib I got pretty excited by that concept and really do want to have that as a "feature".

    I also ran into a thread somewhere a while back about a guy who hooked up his fighter-jet oxygen mask to a CPAP machine he found on ebay so that he could have real flow and also be able to control it with a panel just like the real thing. I thought this was a brilliant idea! Definitely something I want to use when flying fighter jets.

    For me "immersion" is king, so details like this get me pretty excited. Now when pulling too many G's I'd have the forces sqeezing me to the point of significant discomfort and also since I fly in VR my vision will dim. That sounds great, but the VR HMD I'm going to be using isn't OLED so the blacks aren't really dark. This makes the vision dimming quite a bit less convincing.
    Two weeks or so ago a friend linked me to a video of a couple real world F-18 pilots flying the DCS World F-18 and at one point one of them brought up the hypoxia simulator training they had all gone through.
    This got the wheels turning. I started thinking about how to make the g-LOC experience a more realistic hazard. In the real world if you don't back off quickly enough you lose consciousness and in many cases fly into the ground. In simulation that isn't a danger, so you can hold that high-G turn and get away with it.

    Since I've got the military oxygen mask and the CPAP machine the most obvious solution is to use some kind of gas to simulate a truly realistic g-LOC situation. All that would be required is a small motor operating a valve to control what percentage of the air that goes to the mask is proper air vs. the gas. I could also have a safety in place so to create a maximum time after which it will go back to pure air. Depending on the results of supervised tests I might also try to add electrodes to the setup to give a little zap to wake me up.

    cpacp.jpg mask.jpg

    The first and most obvious choice is Nitrous Oxide. Thanks to the popularity of Nitrous in performance vehicles and motorsports Nitrous is readily available and fairly inexpensive. It also won't raise any eyebrows for someone like me to be purchasing it!

    I figured that since it's used by dentists and such it must not be toxic or anything, and I had also heard of "whip-its" where a person inhales Nitrous Oxide recreationally. The latter provided a perfect opportunity for some testing.

    I ordered whip-its on ebay. Never inhale nitrous (or anything else IMO) for recreational purposes! This is illlegal and idiotic. In my case this was "for science!" not recreational and I had a friend monitoring for safety. If completed I would consider this system to be for my own personal training purposes only.

    whipits.jpg

    In my younger days I experienced loss of consiousness twice. Once because of a HUGE classmate in the auto shop thinking it was funny to "choke people out" and once because my blood sugar was WAY too low when I volunteered to give blood duing Army basic training. As a result I figured I had a pretty good idea of what it feels like.

    The experiments didn't yield the results I was looking for. I remember the blood giving incident pretty clearly because it was far more gradual than the choke-out thing. In that case my vision dimmed like turning the brightness down on a monitor gradually, until my vision was totally black. The "whip-its" instead quickly caused tunnel vision and then brought on what I perceived as a kind of flashing back and forth between black and red. There was also a loud noise accompanying this effect. A sort of echoing high pitched noise I can't possibly describe. I'm sure I've heard something similar in movies but I can't think of an example. At any rate, this was nothing like the effect I remembered so I believe Nitrous is a poor option.

    This did get me to thinking more about "red-out" and the more distant memory of being choked out and that it differed quite a bit from the blood incident. In that case I think what I remember was my vision slowly fading to red, then the red fading to black.
    At this point I remembered a third more recent but less severe experience I had. The most recent time I rode "Kingda-ka" at six flags great adventure I was very disappointed that I'd gotten out of shape (or old) enough for it to have physiological effects. I definitely got some grey-out from the forward acceleration. It happened, and then was over, so fast I don't know if there was any red. This memory did also make me realize that the onset can be super fast.

    kingda ka.jpg

    Anyway after the disappointing nitrous experiments I didn't know what other gasses I could easily acquire that wouldn't be harmful. As such i had to try a different angle.
    I fabricated a setup with a wide elastic strap into a possibly the worlds most comfortable garrote instrument! In order to get the tests done quickly and as safely as possible I sat down in my sim seat setup and started flying. While I had my eyes and attention firmly fixed on the simulation I had my friend pull the cords to tighten the strap around my neck. I immediately noticed the discomfort but I thought it still worth finding out if the effect matched up more closely to what one would experience in a fighter jet so I didn't try to call for him to stop. The experiment was successful, and even indicated to me that I might be able to use a more gradual means to provide red-out for negative g's. The physical feeling was still a serious problem though. Even with a super soft interface and the wide stretchy material there was no way my brain was going to accept this as being g-force induced.

    I gave it some thought and came up with the idea of using an inflatable device around my neck with a rigid exteral to keep it from expaning outward. I'm hoping that the effect of this inflating will be spread over a large enough area, and the inflated collar soft and flexible enough, that I might not be nearly so aware of the cause of the black-out.

    And that's where the experiment is as of tonight. I've been shopping around to see what kind of inflatable device and pump might do the trick. There are some inflatable neck braces and wearable pillows that seem like an obvious choice, but I'm not sure if that will work or if I will really have to design and build my own inflatable collar.
  2. SeatTime

    SeatTime Well-Known Member

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    My Motion Simulator:
    AC motor, Motion platform
    WTF :eek:. I hope this is a 1st of April thing ;).
    • Agree Agree x 1
    Last edited: Apr 1, 2020
  3. Gadget999

    Gadget999 Well-Known Member

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    you are experimenting with something dangerous - it could kill you

    if you want to experience a GLOC go and try a centrifuge or get a passenger ride in a real fighter jet
  4. SeatTime

    SeatTime Well-Known Member

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    My Motion Simulator:
    AC motor, Motion platform
    April fool ...
  5. Trip Rodriguez

    Trip Rodriguez VR Pilot

    Joined:
    May 8, 2016
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    Lake Ariel, Pennsylvania
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    +330 / 6 / -0
    My Motion Simulator:
    6DOF
    =D
  6. Trip Rodriguez

    Trip Rodriguez VR Pilot

    Joined:
    May 8, 2016
    Messages:
    675
    Location:
    Lake Ariel, Pennsylvania
    Balance:
    3,920Coins
    Ratings:
    +330 / 6 / -0
    My Motion Simulator:
    6DOF
    SeatTime called me out, check the date! =P
    • Funny Funny x 2
  7. Gadget999

    Gadget999 Well-Known Member

    Joined:
    Dec 27, 2015
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    1,886
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    London
    Balance:
    11,543Coins
    Ratings:
    +453 / 9 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino, 6DOF
    thank god for that ! I thought we had an erotic Asphyxiation member on here !
    • Funny Funny x 2