January 28, 201114 yr @Brickdemon I would like to make some "digging" videos in the next days Good idea! I will make one as well, but my 8043 is in bits at the moment as I'm replacing a few colors (I don't like the blue and tan and grey parts). I hope to get the final parts in next week! I will be using the original 8043 for the vid. My dual LA's also never have gotten out of sync yet.. but it's not that I've played a lot of hours with it.. I also don't really see it as a digging machine, but a remote controlled moving model of one.. I think it's quite revolutionary to have a great looking, fully functional, track driven remote controlled excavator with just 4 motors you can build yourself (in two awesome models) for only €150. (I payed €119 at bol.com in december) Try to get a cool RC car for that kind of money.
January 28, 201114 yr Guys, just to stay on topic, despite the differing funcionality of LAs and pneumatics..I can see many people mentioned that pneumatic works just like in a real excavator. Yes at certain point, pneumatic actuator works almost in the same principle..a forced compressed medium, resulting in linear force (movement). But the medium is completely different. Real excavators use hydraulic fluid, instead of air..hence the name 'hydraulic'-taken from hydro. Liquid is much more dense than air, which sees why real excavator can move a heavy or light loads with the same precision. Anyway, I can see HUGE possibility of Lego creating an actual hydraulic actuators, where the hydraulic pump is powered by PF motors. The size of the current LAs is almost the same as an offroad 1/8 RC Nitro Buggy shocks, although the body is made of sturdy aluminum. So in theory making a small 'hydro-tight' element is possible. The medium will be silicone oil, which will be safe for the seals. Just picture it as pneumatics with fluid instead of air.. We'll just have to see what Lego has in store for us in the future.. I still think pneumatics are the closest we can get to modelling real life. As much as I would love see hyrdraulics I can never see it happening, even if it is water based (imagine the health and safety issues with a silicone oil!). Imagine all the kids trying to bleed such a system of air? It would be a nightmare for most kids. "Whats all this water over the carpet Jimmy!?" I still don't see the problem with pneumatics accuracy Good idea! I will make one as well, but my 8043 is in bits at the moment as I'm replacing a few colors (I don't like the blue and tan and grey parts). I hope to get the final parts in next week! I will be using the original 8043 for the vid. My dual LA's also never have gotten out of sync yet.. but it's not that I've played a lot of hours with it.. I also don't really see it as a digging machine, but a remote controlled moving model of one.. I think it's quite revolutionary to have a great looking, fully functional, track driven remote controlled excavator with just 4 motors you can build yourself (in two awesome models) for only €150. (I payed €119 at bol.com in december) Try to get a cool RC car for that kind of money. Not hard to find http://www.otherlandtoys.co.uk/rc-excavator-p-2156.html 97.2 Euros. Quite fancy one of those actually Edited January 28, 201114 yr by richthelegodude
January 28, 201114 yr Hello benjiii712, welcome to eurobricks, and my apologies, I did not realise this was your creation. It's brilliant, I love it. If this is just a sample of what you can do I can't wait to see more. Hydraulics would indeed be the holy grail of technic. It would have most, if not all of the good points of both pneumatics and LAs combined, and be more powerful and authentic than both of them in things like excavators and backhoes. You could also use them for power steering and rotary actuators and all sorts of things. It would not have to be any kind of oil, just water, it would be much safer, cleaner and cheaper! And as far as i'm aware, 9 volts of electricity is safe around water (but don't quote me on that!) But as richthelegodude said it might be difficult for the younger builders to use correctly. But then that's not always a bad thing, it's supposed to be challenging, but that might be too much, depending on how well/badly the system is designed. Another concern tho is that it would require a large set of highly specialised parts even for a much more simplified hydraulic system. So my hopes are not high for hydraulics but wouldn't it be great if they did make them.
January 28, 201114 yr Hydraulics would indeed be the holy grail of technic. It would have most, if not all of the good points of both pneumatics and LAs combined, and be more powerful and authentic than both of them in things like excavators and backhoes. Filling a pneumatic system with oil or water(rust?) sounds exciting. Is there anyone out there who wants to try that with a few of his parts? The crucial part of that idea is: How do we get the compressor to soak the liquid? Maybe we can place the compressor piece in a watertight enclosure that's filled with oil or water. And then you have to get the rotary motion of a motor in there without leakink liquid. And we even have to get the oil back from the valves which also increases the overall complexity. So imho it can be done. But it would require so many non-Lego parts that it might be more wise to leave hydraulic systems to other RC toys.
January 28, 201114 yr Sorry if it caused offence, it was only meant as a light hearted bit of fun, besides i'm not sure if Alasdair would appreciate comments like... "but I don't like the pneumatics here at all. They are impossible to control properly and its movement here just look totally unrealistic, imo." Is what I said really any worse considering it was only meant as a bit of fun compared to you lableing his latest hard work as unrealistic? It may be only your opinion, which you are entitled too (it would be boring if we all had the same opinion), what I said was also nothing more than my own opinion. My comment to Alasdair or benjiii712, who actually built it, was my sincere opinion regarding pneumatics in this model, as there were few other pretty similar opinions from different people, too. I did not write it to be appreciated, but to offer my point of view, which is different than yours, but who cares...It is important that we all enjoy this hobby. btw, I am working on a smaller full pneumatic model, and it is great to work with pneumatics, there are MOCs which prosper more with pneumatics. Regarding hydraulics in LEGO, here is something for which constructor claims that it is hydraulics, whatever he meant by that: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=303975
January 28, 201114 yr Filling a pneumatic system with oil or water(rust?) sounds exciting. Is there anyone out there who wants to try that with a few of his parts? The crucial part of that idea is: How do we get the compressor to soak the liquid? Maybe we can place the compressor piece in a watertight enclosure that's filled with oil or water. And then you have to get the rotary motion of a motor in there without leakink liquid. And we even have to get the oil back from the valves which also increases the overall complexity. So imho it can be done. But it would require so many non-Lego parts that it might be more wise to leave hydraulic systems to other RC toys. It might be easier than you think. Remember the fluid resevoir would not be under pressure, so it could be an open topped tank. If you want to be a purist you could use a boat hull I suppose. The pneumatic pump would have to be tested to see if it can pump and compress water/liquid when submerged in a thin enough liquid, but if it can then the drive to it can just drop down into the tank from above. It it doesn't work then it might be possible to make a pump using the one way valve block from the first generation of pneumatics and a small cylinder, or even a valve and a cylinder linked to work in unison. As for returning the fluid to the tank, the switchs would just have to be placed above the tank so the expelled water/liquid flows back into the tank. Of course there are other considerations. Air will leak past the seals much more easily than most liquids, meaning much higher pressures may be attained. This means you may get more power, but you also have a higher risk of tubes popping off, so they will have to be retained. You will also have to gear down the motor pump and possibly use no more than half it's stroke (a shorter throw of the crank will also increase mechanical advantage). Hmmmmmmm. Could that actually work? Please remember folks, if anyone else is considering trying this, use a fluid that won't corrode the seals or plastic of your cylinders (and follow all necessary COHSS and any other relevant health and safety guidelines), and be sure to dismantle, dry and lubricate your cylinders appropriately and quickly to avoid improper functioning or rust. Edit: After reading back my own post, i'm tempted to build a 100% lego (apart from a suitable, really thin silicone based oil used for lubricating air tools (which I happen to already have) or something), fully hydraulic excavator. Anyone else care to have a go first tho Edited January 28, 201114 yr by allanp
January 28, 201114 yr there is a problem. pneumatics doesnt bring the Air back to the tank. so you must put the valves "in" the Tank, to get no fluid on the table. Long ago i had tried it in the bathroom with a big pump, one cylinder and one valve. it works, but why using water when the hose jumps from the fitting? Edited January 28, 201114 yr by efferman
January 28, 201114 yr there is a problem. pneumatics doesnt bring the Air back to the tank. so you must put the valves "in" the Tank, to get no fluid on the table. but if you do this, it would work Like I said, the resevior would not be under pressure, so it can be open topped. The air usually escapes from the system from the valves, although there is no exit port it does not matter, the valve would just have to be placed above the tank so that the escaping fluid would just drain back into the resevior. Edited January 28, 201114 yr by allanp
January 28, 201114 yr Regarding hydraulics in LEGO, here is something for which constructor claims that it is hydraulics, whatever he meant by that: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=303975 Thank you very much Milan! This guy (Timo Kessler) has made some good thoughts on using pneumatic as hydraulic pistons. He uses a much simpler approach then the reservoir+compressor+valves idea of allanp and me. I'm so glad to have German as my mothertongue, so I could understand how he did the hydraulics in his mobile crane. First take a look at this picture: You see six pneumatic pistons packed tighly together, underneath there are another six cylinders. Only the lower ends are attached to the hoses. His carrier includes three different steering angles. So everything is three times here, don't worry it's not as complicated as it may look! The upper cylinders are moved by a heavily down-geared motor. They are connected to one of the steering cylinders at the bottom. Both cylinders and the hose are filled with water. So when the motor pushes the upper cylinder in, the lower cylinder will extract at the same rate. Thus you can control the extent of the cylinder precisely and you don't have any backlash in the system because water is not compressable. This is a really simple solution that might not be what we need to control a large-scale excavator but it might be an interesting option for many other applications, for example: steering of suspended axles without the need to route a second axle through your model attachments for excavators like grabber, or claws Generally it comes in handy everytime you have to transfer precise movement to a hard to reach location. I will contact Timo to ask him whether this solution has worked good for him and if he experienced rust issues. btw: his mobile crane looks AWESOME and features a mind-blowing sophistication, I hope there is a video somewhere... Edited January 28, 201114 yr by grindinggears
January 28, 201114 yr grindinggears, it may be better to make new topic for Hydraulics... This is what he answer me when I ask him how does it work: And by the way, it's not pneumatic, it's hydraulic! Most of them is working as planned, I've tested all the systems.
January 28, 201114 yr grindinggears, it may be better to make new topic for Hydraulics... This is absolutely true. I have started a new thread about Lego hydraulics and I hope we will finally find a good solution for combining the advantages of pneumatics and LAs without having to destroy pieces. The link is here: http://www.eurobricks.com/forum/index.php?showtopic=51439 Edited January 28, 201114 yr by grindinggears
January 31, 201114 yr Not hard to find http://www.otherlandtoys.co.uk/rc-excavator-p-2156.html 97.2 Euros. Quite fancy one of those actually nice! but you get my point..
January 31, 201114 yr its my excavator !!!! and my youtube account some more details: more videos are coming Awesome stuff Benji. It's a shame some members have chosen to ignore the model completely and turn this into a LA vs Pneumatics slanging match (which I'm sure has never happened around here before ) Also a shame that there's only a couple of posts where the member realises that the original poster is in fact not the builder of the model. I would suggest you PM one of the moderators (DLuders is one in the technic forum I believe) and perhaps get them to edit the title and original post to reflect this, as I feel that you definately deserve the recognition for this marvelous model. The fact that everything is remote controlled thus avoiding the ugly "umbilical cord" that is usually a blight on most pneumatic models far outweighs any negatives like the innacuracy of the arm movements. Personally I'm yet to see any excavator built from lego that perfectly mimics the movements of the one I keep on my farm. The fact that you are only 14 is just the icing on the cake. Cant wait to see what you build once you're experienced. Well done.
January 31, 201114 yr I would suggest you PM one of the moderators (DLuders is one in the technic forum I believe) and perhaps get them to edit the title and original post to reflect this, as I feel that you definately deserve the recognition for this marvelous model. The moderator of this Eurobricks "Technic, Mindstorms, and Model Team" Forum is Siegfried, not me.
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