h a l f b a k e r yIt's as much a hovercraft as a pancake is a waffle.
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It occurs to me that a drag racer might have trouble doing a burnout with synthetic gecko textured tires -- they'd have *too much* traction for the front brakes to hold the vehicle back. |
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[+] for look into it further. |
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//... I have a feeling dirt and rain are going to scupper plans for an everyday tyre.// |
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Does rain and dirt thwart geckos? |
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Because tyres wear. So unless you plan a growing tyre that can reconstitute the setae you will start experiencing van der walls forces. |
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Well you could also advertise for your car
insurance on the rims. (see link) |
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Greco Grip Tyres might be a new form of sportswear worn by participants in Classical Wrestling to counter the slippery olive-oil problem. |
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I think there is a salad option/comment in there
somewhere [zen-tom]. |
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//That was a bit of a rubbish anno// |
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Well if we're going to be childish: |
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Geckos have to cope with wear too - you idiot.
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One might have to consider how to either embed the appropriate materials so as to be continuously exposed throughout the tyres lifetime, or to be continuously re-applied to the surface. That's if you don't want a growing tyre, of course. |
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Incidentally, the Wikipedia gecko page includes the following snippet:
//adhesion varies with humidity and is dramatically reduced under water, suggesting a contribution from capillarity. The setae on the feet of geckos are also self cleaning and will usually remove any clogging dirt within a few steps// |
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So dirt may not be such an issue, but the tyres may not be as good in the wet. Then again, that's true of rubber tyres and people still seem to drive around. |
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//It occurs to me that a drag racer might have trouble doing a burnout with synthetic gecko textured tires -- they'd have *too much* traction for the front brakes to hold the vehicle back.// |
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Since they may be at their most useful as a speciality coating for short races, this won't do. I propose some form of small piston to hold the back end of the drag-racer off the ground while they spin their tyres up to speed. I'm not actually sure - is the idea to do this before the lights go green to get their large mass moving? Or is it as I vaguely recall done before the lights come up, to warm up the tyres for better grip later? If it's the latter, you just wouldn't need to do that at all. |
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Wouldn't the sound of thousands of little gecko suckers add to the sound pollution problem?
phack, phack, phack..... |
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//Now that scientists have figured out how geckos stick to walls// |
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Figuring out is one thing. Recreating is what they've had trouble with. Even moisture in the air or tiny amounts on surfaces will ruin current artificial gecko skins in a matter of minutes. Once they can create self cleaning gecko skin, I'm sure they'll use it for all kinds of things. |
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With regards to tyres though, adhesive isn't going to be much use, you need real macro tread to get a grip (and also to drain water away). Driving sticky tyres would increase drag a lot, and cause lots of problems driving on sand/gravel/dirt etc. |
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[bofch80] That is a question asked nowhere else
but the halfbakery I'm guessing. |
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//I was actually refering to my first anno.// |
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In that case - apology accepted. |
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I, for one, will fight tooth and nail to oppose my local Council's right to paint yellow lines on my house and windows! |
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Yes, self cleaning is the real issue. A Gecko surface tire would become a dirt surface tire within a 100 yards. The Gecko's pads are self cleaning partially because they rotate the area being used to allow for cleaning. Also and most crutially the rolling motion is incorrect for Gecko adhesion and removal. You need a down and back motion to lock, followed by a forward and up motion to unlock. If a rolling motion were used then it would slide a little to grip and then tear the road surface off as it rolled. (-) A dragster with Gecko tires would gun the engine the tires would slip till they lock and then the whole dragster would attempt to rotate on the now immobile rear axle or tear that piece of tarmac off the strip. |
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I was thinking flexible pads on the wheel/tyre that as the weight went on opened surface area and engaged van der walls forces. As the wheel turns and the weight comes off the forces are disengaged. |
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Less worry about leaving the hand brake off and
ornate stained glass roads would be beautiful. |
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I may be wrong, but I think gecko feet need a
reasonable amount of force to unstick. |
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The force that holds the gecko to the wall is just
Van der Valk's forces - the same forces that
happen when any two surfaces are brought
together. But the millions of tiny hairs on gecko
feet mean that there is excellent contact (which
there never is between solid objects unless
they're perfectly smooth and flat), so the total
force is appreciable. |
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But you still have to apply a force to do the
separation. The gecko feet are designed so that,
as the foot flexes, the hairs are pulled off the
surface a few at a time, and all the stress (the
pulling force) only has to "unzip" one row of
contact points at a time. This force is very low,
so a gecko can peel its foot off the wall with a low
force. (In contrast, the glue on adhesive tape has
quite a lot of stretch in it, so when you peel tape
you have to overcome the adhesive force over a
fairly broad area of stretched glue.) |
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Although the force for unpeeling is quite low, that
force has to be applied throughout the entire
foot-lifting process, and hence significant energy
is needed to unpeel the foot. |
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If this were translated to a tyre, therefore, I think
you'd waste a lot of energy. |
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//only has to "unzip" one row of contact points at a time.// |
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Isn't this going to happen at the rear point of the tyre's
footprint on the road surface as that part of the tyre
flexes and lifts up? If the gecko grip works well for
horizontal forces but releases easily for vertical forces (and
I dont know if it does) then this would work just as [MB]
specifies. |
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I have since posted a [link] where my old alma mater has
built a small gecko-grip vehicle with tank treads which
presumably release that very way. More surface area than a
wheel (or a foot for that matter). |
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//Driving sticky tyres would increase drag a lot, and cause
lots of problems driving on sand/gravel/dirt etc.// |
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Perhaps one should just drive on relatively clean, smooth
surfaces - like the sides of glass skyscrapers. |
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Jeesey Pete. I've had to rescue geckos from my stainless steel
sink before. I don't know why they can't get out. Maybe
humidity is a factor. |
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