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Post by Cybermortis on Nov 1, 2012 21:44:05 GMT
This was an idea I posted over on Discovery a few months back, but I thought I'd post it again on here in the (possibly vain) hope that it could be turned into an example as to how this section of the board would/should work.
Did you hear about the guy who made a wooden car? It wouldn't go...
OK, compulsory school-yard joke done. Just need to confirm that I did in fact use find, and while this more or less crops up once or twice in some form I couldn't find this specific question/idea;
Could you make a car entirely out of wood?
I don't mean just the frame or panelling, I mean the engine, brakes, gearbox etc?
Specifically might it be possible to create a wooden engine?* - the rest strikes me as a matter of design rather than material. But the engine, well part of me just wants to laugh at the idea...another part can't help but wonder if it isn't possible.
(*OK, so the spark plugs and electronics can't be made out of wood).
I'm thinking here more along the lines of an RC 'go-cart', rather than a sedan. RC since, well, its wood and (possibly) gasoline (although something that burns at a lower temperature might be an idea) could be a dangerous mix. Go-cart since smaller would be easier to make.
I was as really interested in trying to figure out if an Internal Combustion engine of some description could be made out of wood. Or more accurately if you could make such an engine that would work. Every other part of a car, with the possible exception of the radiator, seems little more than a matter of design and careful accurate carving.
I like the idea of using compressed air, although the tanks needed might make the vehicle to heavy. Are there other fuels that could be used in an ICE that have a low enough ignition point they wouldn't set fire to the engine? Alcohol maybe? Could that work?
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Post by memeengine on Nov 1, 2012 22:41:56 GMT
Could you make a car entirely out of wood? (*OK, so the spark plugs and electronics can't be made out of wood). If you stick to it being "entirely out of wood" (and want more than an unpowered go-cart), the answer will be no. As you note, the electronics will require metals, ceramics, plastics and semiconductors. Hoses/pipes are difficult to make with wood. It's also difficult to make a tight seal with purely wooden components that also allow movement (as you'd need in the cylinders of an IC or steam engine). So the real question is how much of the car can be made of other materials but still be considered a wooden car at heart?
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Post by OziRiS on Nov 1, 2012 22:58:30 GMT
The question is: Can you make a CAR out of wood, right?
Why the obsession about the internal combustion engine? Couldn't you just go with an electric engine and save yourself the wory of fire hazards that way? It would still be concidered a car, wouldn't it?
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Post by Cybermortis on Nov 1, 2012 23:14:03 GMT
The question is: Can you make a CAR out of wood, right? Why the obsession about the internal combustion engine? Couldn't you just go with an electric engine and save yourself the wory of fire hazards that way? It would still be concidered a car, wouldn't it? Not really, because like a spark-plug an electric engine isn't something you can make out of wood. If I was concentrating on an ICE engine it was from wondering if (allowing for those components that would HAVE to be made from metal) if wood could be used this way. Or failing that if there was some form of engine that could me made entirely out of wood and provide enough power to get the thing moving under its own power. Everything else in a car - in terms of what is needed to make a vehicle - could or should be 'easy' to make out of wood. The frame, for example, could be secured without using nails. Which is why I wondered specifically about the engine.
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Post by memeengine on Nov 1, 2012 23:53:28 GMT
Everything else in a car - in terms of what is needed to make a vehicle - could or should be 'easy' to make out of wood. The frame, for example, could be secured without using nails. Which is why I wondered specifically about the engine. Even if we put aside the engine for a moment, cooling could be a problem with purely wooden materials. Wooden bearings would be comparatively high in terms of friction and wood doesn't have a particularly high thermal conductivity, so removing the heat from bearings could be a problem. Also I'd guess that wooden components would exhibit wear much quicker than metal alternatives, so the machine would need to be engineered with greater tolerances in mind, if sustained operation was a requirement.
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Post by rikkochet on Nov 2, 2012 13:51:46 GMT
Steam power is possible, though firebox life would be short. Wooden boilers, albeit with iron hoops, were in use for years; should be fairly simple to construct a wooden boiler reinforced with a timber frame. Likewise cylinders.
I agree that bearings would be a problem, but does the car have to be fast? I seem to remember that timber wheels and axles were around before iron was available for bearings.
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Post by trakmec on Nov 3, 2012 0:01:18 GMT
umm,… would wind be an acceptable source of power?
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Post by chriso on Nov 3, 2012 3:14:46 GMT
Heck, for that matter, would muscle count? If the criteria is a self-propelled box on wheels, and it doesn't have to go fast, use pedals linked to some wooden gears.
I am going to try for an all wood engine. As I see it, what it comes down to with those is cooling. With that in mind, I see three conventional possibilities.
Option number one would be an Internal combustion engine, but with very little resemblance to modern ones. Powered by diluted alcohol with oil mixed in for lubrication, their would be enough water in the mix to keep the cylinders below the 350F or so that wood starts smoldering at. Because of the large amount of water, however, combustion would proceed extremely slowly, and so to make up for it a massive central cylinder would need to be used, connected to a flywheel. This also keeps the speed of the components within a range wood could easily handle. A carburetor sends out the fuel, and the piston is lubricated by the oil distributed into the alcohol water (which, by the way, is one of the reasons for alcohol as a fuel). It would be slow, but provide a (relatively) high degree of torque, much like a tractor. I am not entirely sure, however, if you can get the concentration of water high enough to cool it while still allowing the alcohol to ignite.
Option 2 would be, as already mentioned, a steam engine. To make the whole thing wood, the firebox would either have to have an extremely small flame, or part of the boiler would have to be made out of a porous material so the water could leach through and cool the boiler. Both of these would obviously limit the operating pressure of the device. From their it would be relatively easy to make a cylinder setup.
Option 3 would be compressed air. This would be the easiest setup mechanically, in my opinion. Steam engine-like pistons, except without the need to heat the wood the porous part of it could be eliminated enabling it to be filled to much higher pressures. This of course means better performance and longer range.
I wonder if some types of wood are highly conductive to heat. If one can be found that is, a steam engine would be much easier to make without burning a hole through your boiler.
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Post by silverdragon on Nov 3, 2012 8:57:56 GMT
Ya know, I made some interesting discoveries when I went away and tried a few things because of the thread in the last place..... First one, I tried various woods on this, I tried to make a reasonable suspension damper out of wood. RC scale, 1:12th. Wooden cylinders, forget Pine, the oil leaks out faster than you can pour it in.... Bamboo?... Too fragile. I got some Box wood, that was "passable".... I have some heavy "Iron wood" from my late fathers supplies that I fashioned some passable cylinders that didnt leak, and I have made some passable pistons that will work inside as well... Of course, they are making use of rubber seals ... (No oink oink throw-a-fish joke?.....) I am wondering, (quite a bit... I lost my sat-nav.... ) if by THAT experiment, Iron Wood, can that be used as a basic cylinder block?.... Can you fire repeatedly without damaging the wood too much?.... Cooling.... that WILL be a problem. I suspect a cooled intake may help?.... Its going to have to be a low pressure engine.....
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Post by memeengine on Nov 3, 2012 11:51:29 GMT
I am not entirely sure, however, if you can get the concentration of water high enough to cool it while still allowing the alcohol to ignite. Seems to me that would lead to the insides of the cylinders becoming warm and damp. As the pressure rises during the cycle, the dampness would be pushed into the surrounding wood causing it to expand. That in turn would reduce the freedom of movement for the cylinder and valves. So you'd need there to be a large expansion tolerance built into the cold engine (and you'd be looking at materials other than wood to seal the gaps) Option 2 would be, as already mentioned, a steam engine. To make the whole thing wood, the firebox would either have to have an extremely small flame, or part of the boiler would have to be made out of a porous material so the water could leach through and cool the boiler. As I touched on in a previous post, a steam engine requires a lot of piping both for the water and for the steam. Creating a continuous wooden pipe that is leak-free would be quite a challenge. There's also the problem that wood, as previously alluded to, is a thermal insulator. So getting sufficient heat from the firebox to water inside a wooden pipe to generate usable steam would be a challenge. Option 3 would be compressed air. This would be the easiest setup mechanically, in my opinion. Steam engine-like pistons, except without the need to heat the wood the porous part of it could be eliminated enabling it to be filled to much higher pressures. This of course means better performance and longer range. How would you store the compressed air? Also you'd still be faced with the same wooden pipe problem as the steam and IC engines. Higher pressures would require stronger seals at any joins.
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Post by Cybermortis on Nov 3, 2012 13:01:35 GMT
Maybe we should figure out what we are aiming for, and what we'd have to work with.
First off I think we should consider this a proof of concept rather than a practical 'car'. In this light we can lower the expectations, in so far as to not require high performance.
Lets say that what we are aiming for is a vehicle that is self powered and capable of carrying a single occupant at a walking pace or better (this would be around 3 mph) for around 5 minutes. If this can be managed them better performance would be a question of better design and probably trial and error - which is something MB would not have the time to do, and which would probably require far more expert assistance that they'd want to have. Assume that the occupant is Buster, as some types of engine may be judged too dangerous to risk having any of the cast nearby when it is in use. (Even if the 'car' is considered safe, assuming Buster is in the seat will make no difference really).
The design itself needs not look like a 'car' beyond the frame and wheels. As I said I think 'cart' would be a better starting size, large enough to get useful data but not so large or complex it would take them weeks to build.
Material-wise lets stipulate they are permitted to use wood and plant based products. This would include rope (which you can make from bark) and natural rubber. Although not plant based I think lard would be acceptable as a lubricant (although sunflower oils and the like would be much more in keeping with the idea) I think this might be relaxed or ignored for safety or practical reasons. For example a metal plate or cage to protect the driver is acceptable, as would be using metal nails to secure the frame - You could make a perfectly good frame with wood alone, but this would take a LOT of time they wouldn't really have and not really prove anything. Likewise if they are using rope they don't automatically have to use natural fibre-rope, although hemp-rope should be fairly easy to get hold of.
As far as the engine goes, self-powered would omit sails (which would in any case make it a land yacht).
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Post by Cybermortis on Nov 3, 2012 13:24:20 GMT
Option number one would be an Internal combustion engine, but with very little resemblance to modern ones. Powered by diluted alcohol with oil mixed in for lubrication, their would be enough water in the mix to keep the cylinders below the 350F or so that wood starts smoldering at. Some figures for the ignition point for various fuels can be found here; www.engineeringtoolbox.com/fuels-ignition-temperatures-d_171.htmlWood shows a figure of some 300C/572F, although the figures also list dried pine as 427C/800F and dried Oak as 482C/900F. There are quite a few fuels on that list with ignition temperatures below this, including it seems gasoline (400C/752F). Of course these figures don't take into account friction or what effect those fuels would have on wood.
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Post by memeengine on Nov 3, 2012 14:28:57 GMT
Wood shows a figure of some 300C/572F, although the figures also list dried pine as 427C/800F and dried Oak as 482C/900F. There are quite a few fuels on that list with ignition temperatures below this, including it seems gasoline (400C/752F). Of course these figures don't take into account friction or what effect those fuels would have on wood. Quite, I suspect that the ignition point of dried oak will be lower once it becomes saturated with gasoline. It's also worth bearing in mind that sustained combustion would lead to cylinder temperatures that were higher than the ignition point of the chosen fuel.
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Post by trakmec on Nov 4, 2012 5:58:40 GMT
OK for clarity's sake you mentioned plant and animal materials as being acceptable for use in this vehicle, but is wiring and electronics allowed as part of a starting/ignition system? Steam maybe doable without electrical power, but most ICE’s I know of will require something to spark. Or is this engine to be steam powered?
I do like this idea it offers some real challenge. For the engine can't some woods be kiln dried to harden them, and remove moisture?
Also the bearings could be of a roller bearing type, think longer dowel rods around the axle shaft and not steel marbles. With some Crisco added that should handle the stress and reduce heat enough to move it around a bit
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Post by chriso on Nov 4, 2012 9:33:35 GMT
If your going for an all natural ICE, I can think of a few ways.
What first came to me would be setting the next stroke off with high-temperature exhaust from the last. This, as you might imagine, would probably be a bit dangerous.
Second, forget your traditional ICE design, and go with a hot bulb engine with a stone of some sort as the bulb. Assuming that's allowed, it should work.
And if it truly has to be completely organic, a hot bulb design with a piece of burning as the ignition would work as well.
And on the subject of storing compressed air: Wax. Wax on wood.
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Post by Cybermortis on Nov 4, 2012 16:43:46 GMT
OK for clarity's sake you mentioned plant and animal materials as being acceptable for use in this vehicle, but is wiring and electronics allowed as part of a starting/ignition system? That is a good question, and in fact this may be the heart of the question/idea/myth - maybe instead of asking if you could make a wooden car, I should have asked from the start if you could make a wooden engine? Which might be a more practical project than an entire 'car', since you could use an existing cart and put the new engine in it without messing around with things like brakes and gears. When most people think of an engine they think of an ICE or Steam engine, or possibly a vacuum engine - some of which have been made from wood. (Google 'wooden engine'). So maybe we should concentrate on these types of engine, rather than considering more exotic (or primitive) types. An ICE engine would require metals and ceramics for the electrical system*, and frankly I can't see a way around that. However, such an engine seems on the face of it to be theoretically possible, as there are more than a few fuels that have a lower ignition temperate than wood (Glance at the list I linked earlier). It *might* be possible to find a fuel that combined with the heat of friction in the engine isn't going to set the engine aflame within seconds of being started. So if this is a case of making an engine that could run for a few minutes this might work - and certainly this is something that could be tested in small-scale with ease. Steam engines are a different matter, but the main concerns would be complexity and safety. Steam engines require pressurised tanks, and wood is not what you would want to use for this. It would also require a LOT of expert help in looking at various designs, which I suspect MB would not really want as they really want to be testing things the cast can do on their own. *Edit; Unless you used the igniter from a lighter maybe...would that be possible? Use a Piezoelectric system/material to create a spark as the piston descends?
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Post by freegan on Nov 4, 2012 17:23:00 GMT
Perhaps a diesel fueled engine would remove the need for electronics, ceramics and non-wood components. Provided that the fuel is pre-heated and the compression ratio of the engine can be made high enough, self-ignition is quite feasible.
Bio-fuel diesel would maintain the plant-based theme.
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Post by chriso on Nov 4, 2012 17:34:09 GMT
Perhaps a diesel fueled engine would remove the need for electronics, ceramics and non-wood components. Provided that the fuel is pre-heated and the compression ratio of the engine can be made high enough, self-ignition is quite feasible. Bio-fuel diesel would maintain the plant-based theme. I considered posting that, but I threw it out due to the necessity of a high pressure fuel pump. Your just not going to make one of those of wood
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Post by trakmec on Nov 4, 2012 19:17:07 GMT
Chris O: wonderful idea the hot bulb, should be some rocks that could be used as a glow plug, perhaps coal? Just not sure how to do the initial heating.
Although it seems we have narrowed this down to more of a wooden engine block than a car, which in its own has some interesting challenges, not the least of which being why? But that has never deterred us before so why not. I believe some of the cooling/burning issues mentioned earlier can be address with a wooden block engine the same as a traditional iron block lots of channels thru it and run coolant to draw off heat.
More clarification please, with this “green engine” and the allowance of electronics and such are we allowing any and all kinds of wood construction such as laminates, and plywood? Or is it to be a big machined block of hard wood?
For that matter paper is a cellulose and sort of a plant or wood product could that be used? Pycrete proved exceptionally strong I wonder how a fire retardant and epoxy treated paper product would work for this engine? If that even falls within the rules? Such a mix would open up some construction possibilities with advantages.
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Post by Cybermortis on Nov 4, 2012 19:34:34 GMT
More clarification please, with this “green engine” and the allowance of electronics and such are we allowing any and all kinds of wood construction such as laminates, and plywood? Or is it to be a big machined block of hard wood? *Note to self, when replying make sure it is the 'reply' button you press and not the 'edit post' one...* Good question. My thinking is to treat this as if you are in the middle of nowhere with a car that lacks an engine (yet for some strange reason you do have fuel lying around...maybe gas bottles for a camping stove. You have something or someone you need to move as quickly as possible to another location - say an injured friend, or the plans for the latest superweapon you need to give to the Rebels so they can send a farm-boy out to destroy it* You have tools and plenty of wood but nothing else to work with. In this situation could you fashion an engine out of wood? Or rather what would it take to make a working engine out of wood? (*OK, so I left 'believable' three exits back...just go with it )
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