Does the frequency of the buffet increase or decrease as the stall worsens? Is there change in amplitude?
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How hard would it be with a small compressor to rig up a g suit…that runs off of g data from the sim.
This is really exciting…
Depends.
The number of times I explain there is no such thing as a technically correct simple answer to a simple question in aviation. Simply put if you enter the stall rapidly the symptoms of the approaching stall will all occur more rapidly. As a result many of them might not be noticed. If you are firmly holding the controls you will probably not feel the buffet even if it is pointed out to you. It is important to hold the controls lightly. The aircraft will speak to you and tell you she is unhappy with what you are asking her to do. If you enter the stall with a marginal rate of loss of airspeed the buffet and other symptoms of the approaching stall will be present for longer giving you more time to respond.
NB stall speed increase with angle of bank make climbing turns after take off and descending turns onto final the flight regimes where students try to kill their instructors.
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Well, yes. Buffet is the term most widely used in aviation, for the phenomenon we are discussing.
Yes, I’d go along with that. Although it depends on the aircraft. A tight fibreglass kite will just vibrate, but an old tin can can resonate pretty bad… 
I’d say the amplitude increases more than frequency.
It all depends. If that turbulent air from the wings hit the stabilizer, you will feel it in the entire airframe. If it starts to resonate with your elevator the vibrations in the stick will be more pronounced.
You really need to know the signs that the aircraft will show you, as it is about to fall out of the sky.
Why would it be dangerous? The DCS sim pilot is normally not restrained and the amount of inflation deflation is minimal. It just gives a sensation of g loading. It does not reflect actual g loads.
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I was replying to what @schurem mentioned above about a pressure collar choking you out. But it gave me the idea of a full pressure suit that reacts to g unit measured in the sim itself. Almost like a set of g pants you could wear while flying to give some actual real time feedback similar to your tornado experience.
I need to think about how to implement this as I think its a fantastic, if slightly impractical idea. But I like the thought of how it could work with a small compressor integrated into a seat.
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The Viggen sim I tried had inflatable G-pants. I have never flown with G-pants, but I have pulled 6G without them… The G-pants are supposed to help you contract your leg and belly muscles. It’s not like you can fly around and let the G-pants do the job, so to speak. So I’m not sure what the simulated G-pants did for the sim experience? I felt that it would be pretty unnatural to squeeze my abs, butt and legs, without feeling the onset of G forces, but the pants inflated anyway…
I think the balloon, or bellows as it was called in the Viggen sim, and a harness tightener, did more for the overall immersion.
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Ok boys and girls the demo is live. Still not sure it gets the point across; not enough in speaker version, and perhaps too much in the headset version. And as I mention a few times - I have the amp maxed out here to hopefully demo the worst case (but it is subjective).
And, what you RL pilots describe is kinda what I feel. Or as close as $200 will ever get me 
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What you say here is kinda why I’ve backed off on the G-feel in the haptic system. I mean, I want it to tell me something is happening but I’d rather feel the stall buffet more. Have to balance them out, for me it’s about 60/40 Stall/G. Just depends on the sound samples and your gear.
Now, some “sim jeans” for G sound like good idea. Not sure I’m ready for that yet
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This is important to keep in mind!
Thanks for the video!
Seems like this feedback works a lot more like I wanted the JetSeat to do.
At 7:15-7:20 there’s a sort of pulsing vibration before the buffet came on constantly. Was this the beginning of the stall buffet vibrations, or was it something else?
It sounded a lot like the type of vibration I got from the JetSeat, only that was as much as I got from that system.
I think you sealed the deal here, @jross!
I need to do this!
Yes. You feel it before you can hear it. When it is audible it’s already going at, maybe, 50%? Hard to give it an exact number but it’s felt before it’s heard.
And again, it depends on your system. The transducer linked too (the one I used in the example build) I don’t think ever makes noise no matter how high you crank the amp - the puck isn’t very big/heavy. Or maybe it’s built slightly differently.
It’s just so hard to demo this. Need an app that shows a bar of the output (in this case the Stall effect), but even then not sure it would translate. Hmmm, maybe a small cat collar bell taped to the plate holding the gizmo? Hmmm.
I’m not sure any transducers are made for flight sims specifically, especially concerning something like stall and G. Seems you’d need more room for ‘excursions’ (travel distance) for something that is sensed across a broad range, from just a ‘nibble’ to a full on spank. So to speak…
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Ordered a set of four Dayton Audio Bass Shakers and an Amp.
This will be fun!
Oh, and @Troll, those times you ref’d: in the video you can see that I’m only at about 1.5G so the vast majority of the feedback was from stall. And the stall WAV file feels like it was recorded at a lower frequency perhaps as it will make noise sooner at higher levels than the G; just something about the puck mass + freq + amplitude + blah blah?
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What sold me in this was the way you entered secondary stall when recovering. That looked incredibly real.
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Yes, it’s definitely there. Oh, and above I meant Stall was higher freq than G. I just did a rough measurement and Stall WAV sample is about 60 hz and G is 22 hz. All very rough WAGs.
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Trying to convey how something feels isn’t easy…
But you’re doing a great job so far!
I’m not sure about the sound of a stall. But I think the smell is a lot like poop in the pants…
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That air bellows in the seat seems backwards. It should have been inflated at normal g and slowly deflated as g increased to simulate getting pushed down into your seat, then reinflated as the g’s came off.
The original incarnation of Mission to Mars at EPCOT put everyone in a centrifuge with a video screen and faux controllers in front of you. When liftoff happened, you were PUSHED into your seat. They cranked it up to 4g’s I think? Then when MECO happened it was an instant cut and you felt weightless (even though it was back to 1 actually). Better than the old full-motion Afterburner arcade game from WAAY back by a big amount.
I would’ve loved to hook up a flight sim to that rig…but Disney wouldn’t allow it of course! They later shut the centrifuge down after a handful of people had heart attacks, totally ruining the ride.
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The experience wasn’t backwards anyway.
There wasn’t much displacement in the bellows. The experience was more a pressure, like you were pushed down in the seat. The feeling when unloading after pulling G was very convincing, when the bellows deflated. That really felt like you got lighter in the seat.