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Tilting 4WD 'Spider Car' Makes Light Work of Bizarre Terrain
Zothecula writes: The Swincar Spider is a remarkable tilting 4-wheeler concept that boasts absolutely ridiculous rough terrain capabilities. Each wheel has its own electric hub motor and is independently suspended on a spider-like limb. The result is a vehicle that leans into fast turns like a motorcycle, but can also happily go up or down a 70-percent gradient, ride across a 50-percent gradient that puts the left wheels a couple of feet higher than the right ones, or ride diagonally through ditches that send the wheels going up and down all over the place like a spider doing leg stretches.
If you look at vehicles like the AM General HMMWV you find that each wheel is connected to a control arm setup that places it low relative to where that control arm is mounted to the chassis. That has the effect of suspending the vehicle's center of mass from a higher point. This vehicle has a similar design.
The downside of this, which is also the downside of the HMMWV, is that the load carrying capacity is dramatically different than conventional suspensions and drivetrains, so that passengers and cargo have to be packaged weirdly to make it all work.
Do not look into laser with remaining eye.
Trust me, with so many other sites to waste one's time on, getting first-post is not the achievement that it once was. Not that it was much of an achievement to begin with...
Do not look into laser with remaining eye.
Just what the backroads need something that makes it own. Look out fish spawning in creeks and shallow ponds, ground squirrels, ground nesting avian life, insect colonies here comes another bunch of idiots to tear up your home. ZOOM ZOOM their goes the neighbourhood! Well that is if Mazda brings one out before anyone else like Honda, Polaris and Skidoo/whoever the heck does not corner first. Oh and I am sure that they will be available in two stroke oil injected hot rod models that can tear the shit out tree roots as well.
This message was not sent from an iPhone because Peter Sellers really was a deviated prevert without a dime for the call
Bizarre perhaps because its French ?
How does it have conventional axle assemblies if there are no axles in the entire thing?
You missed the bit where it said that each wheel had a hub motor in it.
No
I would like to see a bake-off between this thing and a dirt bike. Which one can cross given terrain fastest?
When all you have is a hammer, every problem starts to look like a thumb.
You'll have to be supportive as for some ACs, it is probably the biggest achievement they'll ever attain
"The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
as he is an AC, he probably didn't read a word of the article
"The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
So, who remembers the Spider Bike from Dark Reign?
Fast, can handle any terrain ... but lightly armed and armored.
Really, Dark Reign was a pretty good RTS ...
Tilting 4WD 'Spider Car' Makes Light Work of Bizarre Terrain
I'm guessing whoever came up with that headline grew up in a town. A very flat town.
"A bit of a hill with rocks in" is not bizarre terrain.
systemd is Roko's Basilisk.
this isn't a new concept: there was a quad-bike i saw a few years ago with an amazing 4 wheel double wishbone suspension that could articulate at least 2 feet per wheel, independently. watching the videos of the rider tipping the handlebars side-to-side was particularly interesting, because when they did so all four wheels leaned side-to-side as well (because of the double wishbones). can anyone remember what the company was who did that quad-bike? the demo videos they did of going at about 10mph over 1ft high rocks were pretty damn impressive.
No, you have for reading 4chan.
Slashdot has already surpassed the mantle circa 2012.
Yeah, try to drive one of those in the sort of lava fields we have here, it'd bottom out before it even gets started. ;) Even on less extreme terrain, its clearance looks like a pretty big flaw - it can hardly drive on a flat slope without nearly bottoming out, let alone uneven terrain. They could raise the center, but then they'd also be raising the CG because not on the driver but the batteries are in that center bit, and on an offroader you really want a low CG.
Seems to me the solution is to put the batteries next to the hub motors. Something right next to the hub should never bottom out, and as they're low so the CG will stay low. It also allows you to reduce or eliminate your in-arm power wiring (esp. good given all of the bending that goes on in those swing arms), thus reducing wire mass, wire cost, and wire resistance. If you fully eliminate the in-arm power wiring you'd have to charge the packs individually, but even if you retain it you could reduce it to smaller wires that only need to be able to handle charging currents and inter-pack charge balancing, not peak discharge currents. Having the batteries next to the hub motors, you could upgrade them to pretty much whatever power level you wanted.
Another problem I see is with the use of hub motors. Everyone loves them until they start messing around with them and then the problems start to become clear. One, they're unsprung mass, which reduces your ride quality. Two, they're harder to cool, which limits performance. And three, you shake them to bits even on normal roads, let alone offroad. I'd prefer each wheel being hooked up to a small high power motor, connected to the wheels via a stubby CV joint (which should lose only a fraction of a percent of the energy transmitted). That way you keep your unsprung mass low, your motors are easy to cool, and they're not shaken to bits.
This thing is underpowered, but with some proper design choices there's really no limit to how high powered it could become.
The last issue I see is, if you're making an offroader, do you really want motors and wiring connections somewhere that they're going to get wet? Do you want to have your wheel drop into a deep puddle and suddenly short out? It seems to be that they really should have the motors (and as per above, battery packs) protected by a cowling. For transmitting the power to outside of the cowling I see two options. One is to use a waterproof rotary joint, like submarines use, although those are somewhat lossy. A better option might be to have the rotor simply penetrate the cowling (with only a small clearance around it) and use your pack / battery air-cooling system to maintain sufficient positive pressure inside to resist water influx - around 5-10 PSI should be enough for unbridged river crossings, while only 1-2PSI would be needed if you only want to be able to handle the occasional puddle. The air ingress to the cooling system would need to be located as high as possible, of course, whatever design one chooses.
(Yeah, this is something I've been thinking about for quite a while, I'd love to build my own go-anywhere electric vehicle some day ;) )
I'll never forget the last thing grandma said to me before she died: "What are you doing in here with that knife?!?"
Once Jezza gets his steak-soaked hands on it, he will crash it Robin Reliant style.
... and hardly "extreme".
https://www.youtube.com/watch?v=w_F7QrR4Ur8
That rig is bad-ass...
You're messin' with my Zen Thing, man.....
https://www.youtube.com/watch?...
If you want that type of off road capability, I'd think you'd be better off losing two of the wheels on one side. We could call it a "dirt bike" or something.
Seriously though, it seems like a lot of effort to let you sit on your butt, when a dirt bike can go everywhere this could. An electric two wheel drive dirt bike would be cool.
You're forgetting, rivers don't stand still. One can interpret the velocity of the water as relating to the volume of an imaginary water column above the surface, h=v/(2g). So a 10m/s (22mph) flow is equivalent to a 5 meter (197") water column. The force of fast flowing water is a more significant impact than the water depth, at least in a worst case.
I'm not sure what you mean by "at those volumes". Volume is relatively irrelevant in this context, and only really matters for the motor itself anyway (batteries, having no moving parts, can be water sealed on their own easily), and modern electric motors can be pretty tiny versus their power output. What matters is flow rate combined with pressure. The required flow rate in turn is related to the heat output of the motor. A "normal" motor for a vehicle like this a couple meters per second airflow in peak conditions, while a really high power low profile motor like one of the EMRAX ones at peak would need somewhere along the lines of 15m/s airflow at these sort of pressures (average airflow needs being much lower than the peak). Either way, at pressures of only several PSI, you're just looking at a rotary-vane air compressor, nothing like a piston-driven shop compressor or the like.
The other alternative is of course a submarine-style waterproof rotary joint. But it's an extra cost, will cost you some energy, and either way you still need to cool your motor and pack (unless you only ever operate in a very low power regime)
I'll never forget the last thing grandma said to me before she died: "What are you doing in here with that knife?!?"
Oof. I need this.
Spider car, spider car,
Goes wherever that spiders are.
Climbs terrain, any type,
At least that's what they say in the hype,
Look out!
Here comes the spider car.
File under 'M' for 'Manic ranting'
Indeed, but it's not the average speed that matters, it's the peak. When water funnels between rocks it can end up moving much faster than the average speed, and it also moves faster below the surface than on it. My personal preference would be more pressure than is necessary rather than too little; the concept of one's vehicle dying in the middle of an unpredictable glacial river is rather scary. Then again, I'm a big chicken when it comes to highland river crossings (had to do a bunch about a month ago**) so I probably have an overabundance of caution in this regard ;)
** Word to the wise: When driving in a wilderness location with lots of fords, make sure that your vehicle hasn't accidentally slipped out of 4wd before your first crossing, not after half a dozen nail-biting crossings of slipping along riverbeds while steam rises from your engine compartment. ;)
I'll never forget the last thing grandma said to me before she died: "What are you doing in here with that knife?!?"
Nope, all worlds are ours except Europa, hummers be damned.
Wow, nasty much? Along with the half-wit up-votes.
Actually, the OP is correct:
- The term "Axle Assembly" refers to the axle housing as well as as the actual axles.
- And if it doesn't have axles, how come the wheels don't fall off?
- And having hub motors adds essentially nothing to it's off-road ability. It could as well use chains, hydraulics, or more conventional shafts and universals.
It's essentially no different to a conventional 4WD, except that the pivot points are above the center of gravity.
The very last shots were impressive. Scale it up, harden it, and put a diesel on it and they might have something. An alternative would be scaling it up less, harden it a little less, and turn it into one of the buggies that special forces seems to use. I can see some value in it and, as it is, it is fine. It is fine because, as it is, it is a toy and meant to be a toy. The articulation in the last shot of the video on YouTube is impressive though, credit where it is due. You can get a Jeep to do that, to some extent, but not without a great deal of expense and a great deal of fragility.
For what it is, a toy, it is just fine though. And, again, if you look at the last shots of the video you can see how vastly different the angles are. It would need to be beefed up to be of any real value beyond that of a toy. There is not enough clearance. When they go down over an embankment you can see them hitting the skid panel and the only reason it made it over is that it retained some speed and had gravity on its side. They also transversed a 35-40 degree slope like that was impressive. *sighs* It is not. But, again, it is a toy and should be treated as such. As a toy it is novel and looks like it would be fun for someone interested in those things. I did not read the stats but I suspect the battery does not last long enough to even consider it as anything other than a toy for a half hour's worth of fun.
Those statistics are probably available. I did not read one single word of the article because I am not a heretic. I do have an enjoyment of the physics, risks, and excitement offered by off-roading and have a couple of off-road appropriate vehicles but nothing of that nature. I have a fairly fancy 85 Jeep and a handsomely decked out and heavily modified 1998 Ford Explorer Sport.
You may laugh at the concept but with a lift kit, TruxUs tires, front and rear winches, heavy duty suspension, brush guard, Euro rack with spare tires and lights, and all the creature comforts it does exactly what I paid it to do and does it very well. It is not meant to be a rock climber. It is meant to get to the top of mountains, however, and it does that just fine as well as going through scads of mud, over very rough terrain, on old logging roads, and still looks good enough to go to the bar afterwards.
All the mods were absurdly expensive and many were labor intensive so I do not think I will ever bother building another one. It was one of the last projects I did pretty much all by myself and it predates my retirement. I'd just get something built for me these days. I kind of want to do something on a late 70's Chevy chassis. I certainly will not be doing the work myself, though. I am too old to be busting knuckles and getting grease embedded in my skin to the point where it takes a half dozen showers to get it truly clean. I appreciate the geekitude of doing the work myself, and I have, but I really have never been all that fond of it. There is something primal and childlike to packing bearings however. But, it still is messy and labor intensive.
"So long and thanks for all the fish."
Your shared picture... I have friends, much more into off-roading than I am - I do get some joy out of going out to extract them however, who would actually attempt to drive over the terrain you have there. I have two friends, in specific, who would consider it a personal slight by mother nature and would feel the need to tackle it post-haste! They are specifically, very specifically, into rock climbing and have heavily modified vehicles for the task. It is not uncommon for them to call me and have me provide a second winch, block and tackle, and even some pulling power (they are both scientists with one being a physicist) to extract one and that often requires putting them back onto their wheels before we can extract them. Sometimes it is a bit rougher than that and requires that we just say screw it and yank it out while it is still on its side. There is not a whole lot to them that they can not fix.
One is a physicist who works for the University of Maine as a professor and the other was (I guess he still is) a materials scientist who worked at JPL but now has his own place where he does materials certification. He is a sole proprietor and makes great money but has huge expenses. He has very nice toys too. He has his own lab in what used to be a barn and lives out in the woods though not really all that far from civilization. I am not certain what certifications he does but it is similar to Underwriters Laboratories and I think, I do not know, that he may actually do some work for them? I do know he often has government projects and is unable to disclose some of them and I have no idea what those types of projects would consist of. Given that he is a materials guy, well, I suspect that it may be anything from armor to heat shielding. His toys are pretty fun but that's not really my type of job. He does not create anything. He just tests and does independent certifications as far as I know.
But, enough of the mindless banter...
I have a question and my question is this... That looks like Hawaii. Does anyone go out to those areas and try to tackle them with four wheeled vehicles? I found some off-roading pictures from Hawaii when I just searched but they were just on mountains or in some fairly shallow mud. I did not find anybody tackling terrain like that. I ask because, well, it is surprising what some of those vehicles are capable of doing. The two rock climbing friends generally go out in pairs and have spotters with them. They may take four or five hours just climbing a few hundred feet simply because they wanted to try it. They will sit there and ponder their routes, go out with orange marker paint, and will plan the most difficult track that they think they can accomplish. Rolling over (and down) is not uncommon but there is almost no way they can be hurt.
These are not road-legal vehicles, not by any stretch of the imagination. Well, they would be road legal in parts of Florida actually. They go out to specific areas (sometimes the same areas - over and over again) and really plan it. They even go out ahead of time, sometimes, and take pictures of the terrain and will map a preliminary trek before even considering it. I can see the attraction but it is not really my thing though I have gone with them a number of times. It is quite a mental challenge and a physical challenge though one many not think so. It is not easy driving and it is more than driving. Anyhow, they trailer the vehicles in, offload them, and then trailer them back out again. I believe both of them have been 'featured' in one of the off-road magazines. They tell me that there are competitions and prizes that they could compete for but neither of them are into that scene. It is just a hobby for them and it is not at all uncommon for their trek to include some rather complex math scribbled onto the sides of their ledgers. As I mentioned, they are heavily into it.
So, if they actually allow this sort of thing on that type of terrain and it is feasible then I may have a couple of friends who are just crazy enough to
"So long and thanks for all the fish."
Selective reading. The OP also mentioned 'conventional'.
There is nothing conventional about it's axles.
Hmm... More to add, I suppose. Oh well, I was not doing anything better.
With the HMMWV the general safety rule was three of water and fifteen miles per hour. If the water was over a three feet and moving faster than fifteen miles per hour we were not to attempt to ford it unless there was a great and compelling reason to do so. We were to test by finding something that floats and throwing it in the water and then estimating how fast it goes. If it was faster than fifeen mph and deeper than three feet then it was considered unsafe and that we should seek an alternative fording point. If, on the other hand, you have an armored unit in pursuit then you are obviously going to attempt the crossing.
However, an armored vehicle is unlikely to have any major issues crossing that theoretical three feet of water with a fifteen mile per hour flow. It is simply heavy enough and is not submerged enough to be buoyant so it will likely make it through that and worse. Obviously we are talking about a purely theoretical situation that is unlikely to ever be precisely met. HMWVVs were not armored, even lightly armored really, at the time - I was driving them in the late 1980s.
Now, in practice, I can not now or ever say I knew the exact speed of the water. I do know that we fairly frequently forded fairly rapidly moving bodies of water. We would generally lower the tire's PSI by fifteen to twenty pounds per square inch, put on (if not already attached) the deep water fording kit (if the water was deeper than four feet), and go for it. I can say, with some certainty, that we exceeded that safety limit with water that was most certainly much faster than your proposed 6 MPH limit. In fact, I have some photographic evidence that suggests this is not just my own personal experience and that I am not talking out of my ass. Here:
http://www.clublexus.com/forum...
Now we can not be 100% certain of the speed that the water is moving at. What we can do is guesstimate if you will allow such and still consider it evidence. Scroll down on that page and you will see some water fording in action. Given the height of a HMMWV - about 7.5 feet with the tires properly deflated for water fording, take the two feet away for the windscreen, and you end up with a HMMWV in about 5½' of water. If we look at the water, itself, and judge by its depth and then the whitecaps on the top, we can safely assume that the water is far in excess of your six mile per hour limit. It looks like, and this is just using the picture and personal experience which has been trained to observe such but - again - this is just a still picture, the water is fairly close to triple the six mile an hour limit that you have suggested.
I think that, maybe, you are confused in thinking that a vehicle that floats, a boat, is similar to a vehicle that does not float - namely anything that is not a boat with few exceptions. If you examine the above linked photographs you will see that it is quite effective with water moving much faster than your proposed limit. I strongly suspect that is because an HMMWV is not, in fact, a boat. This is the Army and they do get confused but I was in the Marines. The Marines are a department of the Navy. I am no expert but I have spent time with some experts and I think it is safe to conclude that I can spot a boat. The Humvee is not a boat. Automobiles have a number of characteristics that make them different than a boat. The primary difference is that, unlike witches, they do not float.
I suppose you could say that, "Well, we do not know that that water is going faster than six miles per hour." That is true - we do not know that. What we do have is an opportunity to use our own judgment. In my judgment, based on years of observation and a modicum of training, I strongly assert that that water is moving much more rapidly than six miles per hour. I suspect, again - this is subjective, that the water is going so
"So long and thanks for all the fish."
You do not understand how traction control systems work, do you? Physics is not too difficult for a layman's understanding. The ability to power each wheel, individually, is not something commonly seen even in many "AWD" vehicles and even less likely in 4WD vehicles. There is a reason we have posi-track and ESC in fancier cars that do, indeed, benefit from being able to power each wheel individually. What's more is that, with some tweaking and actually few additional components, they could apply proportional power to each wheel individually giving even greater traction.
There's a reason why we have ESC and AWD. Some AWD vehicles only have a single wheel that is powered at the front and rear of the vehicles much like a typical front-wheel-drive vehicle will have one wheel powered for forward gears and one wheel powered for reverse. That is why you have two separate CV shafts in many vehicles. Even some of the low-end AWD vehicles will have only two wheels that are powered for forward and two for reverse. Some ESC only have braking for stability controls. Good ones have all four wheels powered individually and can generally apply anywhere from 30 to 70% of the power to a single wheel when stability control is actively engaged.
I will assume you either did not know or do not understand physics very well but it is a great deal more easy to control if you can apply power to all the wheels individually and even more control is granted if you can apply different percentages of power to different wheels at different times. If, for instance, a single wheel is spinning the system will stop applying power to that wheel and will apply a higher percentage of power to the opposite and diagonal wheel and then work its way around with different percentages of power depending on the friction. It is a bit complex but not totally foreign. Even advanced systems sometimes only use the brakes for ESC. My BMWs have all been rear-wheel-drive so stability control is a combination of braking and, perhaps, power being applied to one or the other of the wheels or, in some cases, less power than I may be calling for depending on how much I depress the accelerator pedal.
"So long and thanks for all the fish."
"In general" is key (and in general people will get *very* mad at you if you offroad on public lands or on private land without permission - me among them). However it's perfectly legal on private land if you have permission. On my land, for example, I sometimes *have* to offroad to haul things around (supplies for fences, trees to plant, manure for soil restoration, etc); I don't have roads that go everywhere, and nor do I want them.
There are three cases on public lands where people won't get mad at you offroading. One is if you're in a björgunarsveit (rescue squad) - they go wherever the heck they need to if there's a person there. The second is up on the glaciers, as those get wiped fresh every year. The third is, in specific locations, there's areas specifically designed for offroading (including difficult rock crawling).
It should also be mentioned that some of our highland roads are worse than what people in most countries would call "offroading" ;) Where they cross lava fields, for example, you'd be crazy to go over them at more than 15kph/10mph, and even that can be pretty jarring in places. But they don't involve any serious rock crawlimg, they're designed to be such that any high-clearance 4x4 can get through (don't even think about it with a regular passenger car, though!)
I'll never forget the last thing grandma said to me before she died: "What are you doing in here with that knife?!?"
Thank you both - I have been to Iceland and Hawaii but only as a pretty basic tourist in both instances. I live in Maine so we have crappy weather too but I still would want a guide. I watched a very boring (to most) documentary about some lady who hiked all over the place and one of the places she hiked was in Iceland. I sort of want to go back and do that but I am awfully lazy at times. I also want to go check out some of the gyms. There are some giant people there and I want to see how they work out. For such a small country there is an inordinate number of giant folks who win that tough man competition thing frequently.
"So long and thanks for all the fish."