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For anyone who wants to know more: This is an application of Jansen's linkage: https://en.wikipedia.org/wiki/Jansen%27s_linkage https://en.wikipedia.org/wiki/J
by throwaway920102 2y ago
For anyone who wants to know more:
This is an application of Jansen's linkage:
https://en.wikipedia.org/wiki/Jansen%27s_linkage https://en.wikipedia.org/wiki/Jansen%27s_linkage
There are other similar linkages but Jansen's is quite good.
For anyone who doesn't have an idea why something like this matters or is inspiring beyond art, legged vehicles have many downsides but one big upside is that you can theoretically avoid the rubber/microplastic particulate emission associated with tires and wheeled vehicles if you can make legged vehicles as good as wheeled ones.
Even an electric battery vehicle with an electric motor charged by a solar/wind/nuclear power plant still emits pure poison into the air and waterways through friction between tires and the road.
Good alternatives would be biocompatible tires (Nitinol mesh tires like SMART Tire company's initial prototype that lacked the rubber coating) or legged vehicles.
- polishdude20 2y agoWouldn't a legged vehicle still have that problem if it can achieve the same speeds and weights that regular cars go at? Scale up a human for example to the weight and speed of a car. Crazy powerful and big legs, big feet, big shoes. The rubber must hit the road either way and push down with a force to propel the weight of this car-heavy legged human at speeds of 100km/h. It would still wear rubber away just like tires do. Legged vehicles aren't a replacement for regular vehicles if tire particulates are your concern.
- necovek 2y agoCouldn't you do away with rubber and shoes since for legs you don't need flat, smooth roads either (so metal legs of a multi-ton vehicle won't have anything to damage too bad). For comfort, you could have springs and air and hydraulic dampeners.
- polishdude20 2y agoThe metal itself would damage the ground that is walked on though no?
- necovek 2y agoYes, but walking on rough terrain would still keep it a rough terrain.
- wizzwizz4 2y agoRough terrain with less and less purchase, until it just turns into a pile of dry dust / wet mud (depending on weather). A legged vehicle as heavy as a car would wear away stone, tear roots… I don't think there's any surface that could withstand heavy traffic, except maybe something ridiculous like a fast-growing woody grass.
- wizzwizz4 2y agoFor some reason, I was imagining a machine with legs like a footstool. Any realistic machine like this would have large, wide feet. With proper suspension, the pressure might be low enough to not completely destroy the ground. Though, I'm struggling to see how this would be better than a wheeled vehicle: you've still got static friction between the feet and the ground… I guess maybe they're flexing less?
- necovek 2y agoYeah, large feet would reduce the pressure on the ground, though it would still suffer some effects for sure — but the goal is to avoid rubber and microplastics, so metal feet it is :) Anyway, I agree that a wheeled vehicle is probably going to win on efficiency just the same, though wheels do require better roads than legs do (eg. common example is stairs).
- wizzwizz4 2y agoA bicycle can do stairs just fine. They're tricky, but not much more than a similarly-steep hill would be. (Of course, that's ignoring wear on the tyres from going over the edges of the steps.)
- fragmede 2y ago> The rubber must hit the road if the wheels were metal and the roadway was also metal, but arranged into parallel small roadways, then we could avoid using rubber and not have the problem of rubber particulates.
- anamexis 2y agoSeems like in that case, you could just use cogwheels and racks, and avoid the complexity of legs.
- deleted 2y ago[deleted]
- mensetmanusman 2y agoMetal particles are more reactive and toxic than rubber particles.
- numpad0 2y agoYou'll get microsteels, microstones, microbrakedusts and microlubricants for trains, by the way. Some of those may also qualify as microplastics too.
- user_7832 2y ago> It would still wear rubber away just like tires do. It’s been a hot minute since I learnt rolling friction in high school physics but (iirc) a very interesting and unintuitive aspect of it is that there’s always an opposing/slowing force on a (rubber) wheel. Only a slippping wheel will not experience a slowdown. Static friction is different from rolling friction, and (I think) can offer zero wear in ideal conditions - but rolling wear is always non-zero.
- deleted 2y ago[deleted]
- immibis 2y agoYes indeed - Jansen's machines are applications of Jansen's linkage :)
- hinkley 2y agoI feel like your choice of phrasing downplays the fact that the strandbeest is created by the guy the principle is named after.
- lucianbr 2y agoIt says these are made of plastic pipe. Doesn't the pipe wear down where it contacts (or even slides in the video) the ground, creating microplastics? Also, it already slides some of the time in the videos. Not sure what the advantage is over a simple slide dragged by a sail.
- ninininino 2y agoStrandbeest is just one legged vehicle. But I was just going on a tangent about an important aspect of legged vehicles in general.
- jpk 2y ago> legged vehicles have many downsides but one big upside is that you can theoretically avoid the rubber/microplastic particulate emission associated with tires and wheeled vehicles if you can make legged vehicles as good as wheeled ones. How do you square this idea with the fact that my running shoes wear out? I'm a legged vehicle, and it's clear that the soles of my shoes wear down over time and the lost mass of the rubber went somewhere. Whether legs or wheels, there are going to be contact patches that have to endure some quantity of sheering force when the vehicle is doing anything other than remaining stationary. It's this sheering force that grates the particulates away from tires, and I presume a legged vehicle would need a tire-like compound on the surfaces it uses to contact the road. So why would legs be different in this regard?
- burkaman 2y agoYou could wear wooden clogs or something. It would be uncomfortable but if you were a robot you wouldn't care. They would still wear out, but sawdust is less permanent than microplastics.
- conceptme 2y agoBefore they used wooden tires
- cenamus 2y agomost wooden clogs come with rubber soles nowadays to make them bearable to wear for more than an hour
- brnt 2y agoOr, we should stop paving road surfaces so wooden clogs work again as intended without being painful after a while.
- rtkwe 2y agoPaving is a solution to a much worse problem of huge maintenance costs of non paved roads and paths. Unimproved dirt doesn't stand up well and gravel needs more maintenance than paving as well.
- dyauspitr 2y agoThat’s a dumb reason. A reason for reasons sake. These matter because they are beautiful and make people happy. They’re also appreciable technical achievements.
- monooso 2y ago> For anyone who doesn't have an idea why something like this matters or is inspiring beyond art... (Emphasis mine) The OP acknowledges that these are beautiful, and then explains other reasons why this work may be interesting or important. There's nothing dumb in that.
- xg15 2y agoIsn't another advantage of legged vehicles being more applicable to uneven/unstable terrain? (Like in this case the constantly shifting water/mud/sand boundaries of a beach) If you wanted to build a similar contraption that is powered by wind but moves on wheels, I imagine there is a much larger chance of it getting stuck.
- crazygringo 2y agoSure, but on the other hand legs produce a LOT more force/weight per square inch, which can lead to them sinking more easily. Which is why what the military uses for unstable terrain is treads like you see on tanks. Same for construction equipment that operates on soft soil.
- xg15 2y agoMakes sense. I suppose the additional constraint here is "with minimal damage to the environment". Like, some caterpillar-type vehicle could move fine on that beach, but you'd definitely see the trace of its movement afterwards... So legs are not a useful movement mechanism for tanks, but they might be for delivery bots, etc. I also wonder about the energy expense. The strandbeests seem to be powered by nothing else than a number of sails and the movement mechanism has little enough resistance that the wind force is enough to pull the vehicle along. It feels as if a caterpillar would have more resistance, though I don't have the numbers. I guess you could in theory make a wind-powered caterpillar vehicle by using a turbine - but the vehicle would probably be slower, I.e. less efficient?
- Cthulhu_ 2y agoYou seem to posit that legged vehicles doing 100+ km/h for hundreds of thousands of kilometers do not have as much wear and tear as rubber tires do. What is that based on? And does it have the same or better friction / energy efficiency? (I know the answers, I'm just trying to provoke you into thinking about your comment)
- aaron695 2y ago[dead]
- IncreasePosts 2y agoAre any companies doing r&d for drop in tire replacements that don't have as much of an issue with micro plastics?
- ninininino 2y agoSMART tire company
- samstave 2y agoSo many people dont know this - the tire muck that comes from theforever chemicals used in all tire manufacture is horrifically bad - to the point where one eco guy I was listening to basically gave up when he learned just how bad the chemicals from tires are. (ill try to find the podcast) -- and he notes how Humans tried to make reefs out of tires for Ocean Life. In dystopian Dark Mirror Humor, I bemused myself with the day dream thought that Michelin Star restaurants, whom are awarded 3 stars for the distance one should be willing to drive is greatest with more stars - meaning that you should be willing to make a journey to the off-beaten path to visit and eat this food (which has yet to be em-poisoned with the forever chemicals our Tires have put into all the densely populated environments, thus this Elite Food is Clean.
- rajnathani 2y agoThere are tire particulate matter capture devices out there, in research at least [0]. This solution plus having a heavy vehicle weight-dependent tax could help (i.e. encouraging more 2 (or 3) wheeler transportation regardless of whether motorized or not). [0] https://www.imperial.ac.uk/news/195595/worlds-first-device-capture-harmful-tyre/ https://www.imperial.ac.uk/news/195595/worlds-first-device-c...
- YeGoblynQueenne 2y agoThere's a question of course about why we're not using legged machines but I think you're way over-thinking this. Strandbeests are just a cool and beautiful art project and there is no more justification that they need than that. Art has a utility all of its own without having to inspire engineering works. Besides which strandbeests are made of plastic tubing which kiind of weakens your argument about environmental friendliness.
- dcuthbertson 2y agoIf your goal is to replace rubber tires, then how about going whole hog and turn the entire road system into a railway system? Tires made of steel, parallel tracks, lots of switching, perhaps regional control systems to guide computerized vehicles along the fastest route keeping safe distances between cars, and cars that automatically link and unlink to create dynamic trains along shared routes. I think that would be a very cool system (although outrageously expensive to realize).
- chairmansteve 2y ago"but one big upside is that you can theoretically avoid the rubber/microplastic particulate emission associated with tires". Flying cars would solve this problem.
- deleted 2y ago[deleted]