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DIY Motion Cabinet: Is it even possible?
RandyT:
--- Quote from: pbj on August 29, 2024, 09:03:00 pm ---Randy, stop being a wet blanket and go into detail about how far your took your project. I’ve got $6 in hand for video of you being thrown out of it.
I sold a fully functioning Miata for $2,000. I don’t think any arcade experience is going to top that, but if you’re differently abled then do whatever you have to do… I’m a waddling barrel and I could still maneuver it.
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My post shows pretty much the extent of where my project sits currently. Honestly, I'm lucky I had the time to get it that far. It's functional, but I wouldn't call it "safe".
Trust me, the $6 is nowhere near enough for me to show you the pain that thing is capable of inflicting. Whiplash is a real thing, and the forces are enough for it to destroy itself. The right malfunction or a misconfigured application is all it takes to put a non-trivial hurt on the machine or me. This is from experience, whether you believe it or not. Each of the actuators I designed are theoretically capable of flinging ~250kg (~500lbs) close to 10"/second, based on similar designs, and there are four of them on the machine. In other words, with a good platform, there's more than a small chance that the 4 units could lift your Miata 10" off the ground in not much more than a second.
God help you if something goes wrong and you aren't able to shut it down, as was once the case when I stupidly tried configuring an untested roller coaster whilst in the seat of the thing. It was throwing me around so bad, it took a good 10 seconds for me to hit the escape key to stop it...on the keyboard that was on my lap! That 10 seconds felt like 10 minutes. The machine had thrown itself off it's floor pads because it was violent enough to only have 2 of the 4 actuators in contact with them at certain points during the ordeal, and it felt like it was close to flipping on it's side. My neck ached for a week afterward. That reminds me, I really need to get that industrial slam kill-switch installed.
I'm not trying to dissuade anyone. But the hard truth is that (almost) anyone can build an arcade cabinet that won't fall over and hurt you. But not everyone can design something with enough power to move in near real-time with a person attached, and do it safely. Driving a Miata is not the same as designing one, and if one average person engineered it, you would be foolish to drive it.
If you aren't an experienced engineer/builder (or at the very minimum, so inclined), and have a limited budget, just go here. It's about as cheap as these things get and you still have to assemble it, but at least the hard work is done and you will be unlikely to hurt yourself or loved ones.
pbj:
This one time, I got suckered into participating in a "do you like video games" study. Basically they put you on a platform in a basement that could move in any direction, you sat a foot away from a screen that completely filled your field of vision, and they'd have you move around in some video game that kinda looked like Battlezone. The joystick and platform input would conflict with each other and they wanted to see what it did to your brain and eye activity. So far, so good. Well, they custom molded a mask that immobilized my head, and I was too fat for the seat belts so they duck taped me to the chair. At one point, some of the equipment fell off and hit me in the face and bounced into the pit below the platform. When I told the researcher afterwards what had happened, he started yelling at me in Greek and wanted to know why I didn't say anything. I mean, you've got me in a basement (in Texas), all lights off, sound proof walls, duct taped to a goddammed chair. Throwing stuff at me would have been the least crazy part of it.
They also wouldn't let me me play Mario Kart on it after the session was over. Jackasses. But that was the most precise and immersive motion thing I've ever experienced.
Here's my contribution to science:
https://elifesciences.org/articles/63405
lilshawn:
RandyT:
--- Quote from: lilshawn on August 30, 2024, 06:15:46 pm ---youtube...
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Now just imagine what would happen if one of those upper ball joints was out-of-spec, the engineer did not fully consider the forces they would encounter, or all of the possible angles combined with those forces. If one of them snapped, that design could allow the two remaining supports, combined with gravity, to angle his body to face directly at the broken actuator arm, which would still be functional and possibly drive it into all of his important squishy parts. Things like this are the ultimate confidence test of one's own engineering prowess and is probably representative of the first stage of becoming a Darwin Award nominee.
--- Quote from: pbj on August 30, 2024, 03:59:35 pm ---...But that was the most precise and immersive motion thing I've ever experienced.
Here's my contribution to science:
https://elifesciences.org/articles/63405
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What they had you on was a commercial-style simulator platform of the type used in aeronautics/NASA/etc. There are massive ones using this design, which have complete cockpits and nosecones sitting on the platform. They are usually referred to as "6DOF" simulators, as they can move in all directions in 3D space. Due to the fact that there needs to be 6 actuators to pull this off, they are the most expensive type, and it's probably one of the safest types, given the number of supports and their distribution. The home version from the same company I linked to earlier can be found here, however, their design is of the glorified wiper-motor approach, which limits the range of motion to some extent. This makes it inherently safer, but probably not as immersive as something which could literally put you near 90 degrees relative to the ground plane in any direction, if the actuators have enough travel. Some have rolled their own versions of this type from common materials to pretty good effect, but using them is akin to stepping aboard a thrill-ride at the jankiest run-down carnival you can imagine and expecting nothing to go wrong. :)
The sad part about your contribution is that the Aperture Science guys probably threw out your results due to the testing anomaly, which is why they were upset. They didn't offer you cake to get you to participate, did they? Spoiler: There is no cake. ;D
pbj:
Yeah, and he also yelled at me for not going exactly over the targets. There was inertia in the video game, so I kept trying to come to a sliding stop. Apparently I was supposed to drive all the way to the target and release the joystick. “Stop taking so long!” Has nobody played Crazy Taxi?
The time perception study may have been worse, that guy had a show on PBS. Hours spent in a sensory deprivation closet saying whether number sequence one or two counted down faster. Made $40 on that one. That scientist got famous for throwing graduate students off a cliff and testing if time dilation during a traumatic experience is real. (I’ve experienced it, it’s real)
Neuroscientists are all nuts, and I’m married to one so I’m allowed to say it.