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Hi everybody, I' ve read a long time ago something like this: LEGO pneumatic cylinder cannot be use as hydraulic cylinder. Is anybody can explain me why ?? May be we can' t use water with cylinder (may be cause of corrosion) but what about silicone (...) (20 years ago, 6-Apr-04, to lugnet.technic)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) I can think of a few concerns that would need to be answered before using a pneumatic cylinder as a hydrolic cylinder: 1. will the seals work properly I'd be concerned that the lubricant would get washed away by water, so the only way to (...) (20 years ago, 6-Apr-04, to lugnet.technic)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) The simplest reason is that when the switch is flipped to one side, the other port is released to the atmosphere. This means that your hydraulic fluid would spill all over the floor. Figure out how to eliminate the free release (hint, only (...) (20 years ago, 6-Apr-04, to lugnet.technic)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) Well one solution to that problem is to position all the switches above a "hydraulic fluid catchment area", however I still think it would be prone to spillage ;) ROSCO (20 years ago, 6-Apr-04, to lugnet.technic)
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| | Re: pneumatic cylinder: why not hydraulic ??
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purpledave@maskofdestiny.com (Purple Dave) wrote in <HvrHn0.Cpw@lugnet.com>: (...) I'd add 7. if you used hydraulics, a cylinder would extend or retract fully with one stroke of the pump. The resistance the cylinder encounters is transmitted to the (...) (20 years ago, 7-Apr-04, to lugnet.technic)
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(...) One key thing about hydraulics has always been "avoid leaks". To switch the fluid, just invent something I've wished for for years - the reverser switch. This switch has four ports, used in opposing pairs. Clockwise in a circle they would be (...) (20 years ago, 7-Apr-04, to lugnet.technic)
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(...) Not necessarily. Assuming both cylinders are the same size, a full pump cylinder stroke will only result in a full working cylinder stroke if the working cylinder doesn't have significantly more resistance than the pump cylinder. If the (...) (20 years ago, 7-Apr-04, to lugnet.technic)
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purpledave@maskofdestiny.com (Purple Dave) wrote in <Hvtrvs.sBv@lugnet.com>: (...) And where would you leave all that fluid? Fluids aren't compressible (yeah, they are, but so much less than air that I'm close enough for government work). (20 years ago, 8-Apr-04, to lugnet.technic)
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Not alone thinked about it a while back,currently studing fliud power and in the fluid power industry (...) Lego pneumatic cannot be used for hydraulic's period! Nor will there be such a thing put out by lego there in the toy industry not heavy (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) I have created a pneumatic polarity reversor using four pneumatic switches. I did an analysis and my pneumatic multiplexor works as a hydraulic switch that does not have a free release. (URL) above picture contains two pneumatic multiplexers. (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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(...) It is my understanding that fliuds cannot be compressed. So a cylinder hooked to another cylinder with fluid in between (assuming no leaks), would always provide 1 to 1 movement. I'm not an expert in hydraulics, but I think your claim above (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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<snip> (...) Hi Mark, I've thought about this in the past, and ruled it out because it is such a specialty. Do you think there is a big enough market to justify a book on this topic? Kevin (20 years ago, 8-Apr-04, to lugnet.technic)
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In lugnet.technic, Kevin L. Clague wrote: <snip> (...) Actually this multiplexer is more efficient because it uses less parts: (URL) (20 years ago, 8-Apr-04, to lugnet.technic)
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(...) The amount that a fluid can be compressed varies with the fluid, the temperature, the pressure and other things. Water can be compressed too much - that's why trucks don't use it for their hydraulic systems. Hydraulic fluid is special oil that (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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| | Pneumatics book?
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(...) Well, there are books about Lego Mindstorms and now a book about Lego trains, both by AFOLs, so I don't see why not. Chapters may look like this: 1. Basics. Components and simple system. 2. Larger basic systems, up to Backhoe Loader (...) (20 years ago, 8-Apr-04, to lugnet.technic, lugnet.books)
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(...) I get the impression you've complicated things by putting different switches at different lever angles. My reverser idea puts the switch lever pivots 16mm apart, all in a line with 2-beams between: BSBSBSBSB along a beam of length 17 holes, so (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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(...) I'd love to see a picture of your reversor, as verbal explanations by themselves are often much harder to comprehend. (...) Again, I'd like to see this. My pneumatic mux that can act as a polarity reversor, can just as easily be used for an (...) (20 years ago, 8-Apr-04, to lugnet.technic)
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(...) Mark, I thought this one through, and I get it. I can see how it works. The solution works equally well as my solution. I don't think mine is any more or less complicated, just different. Less hoses, more T's and other technic parts than (...) (20 years ago, 9-Apr-04, to lugnet.technic)
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(...) If you're short of space you can always double the reverser back on itself if you're using the new switches from 8455, in a similar way to your picture. That's why I like the new switches. A 2x2 switch module is probably easier to accomodate (...) (20 years ago, 9-Apr-04, to lugnet.technic)
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| | Re: Pneumatics book?
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(...) That would be my fifth book, and my second that contains pneumatic models. I'd love to do more models based on a single 8455 set. It has enough switches to make a half adder, and some cool walkers. It is a challenge to live within the (...) (20 years ago, 9-Apr-04, to lugnet.technic, lugnet.books)
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(...) Yes, I just noticed that it was one of your specialities - obvious due to the picture on the Technic newsgroup page. I also major in trains, which take a lot of time, so I haven't had time to develop pneumatics much for a few years. However, (...) (20 years ago, 9-Apr-04, to lugnet.technic, lugnet.books)
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(...) Mark, I think the subject of pneumatic sequencing is strong enough to stand by itself as a chapter. Feel free to read my writeup on the subject (URL) (...) (20 years ago, 9-Apr-04, to lugnet.technic, lugnet.books)
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(...) Syngress found me, and then I co-authored in my first book. It was primarily a building instruction book, with little freedom, except in the model design itself. I wrote my first version of LPub for that book. Syngress had another "10 Cool (...) (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books)
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| | Re: Pneumatics book?
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(...) I've long held the opinion that it is a lot harder to make rigid structures using studless beams. I have yet to build anything of worth entirely from studless, despite multiple attempts. Steve (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books)
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(...) Sorry for replying to my own post but I've just had another thought. Has anyone else noticed all the ancillary junk needed to build a studless creation? Compare it with the basic studded version, all you have is beams, of varying lengths, 1xn (...) (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) A XOR gate has two inputs, one with 1 switch and one with 4 switches. The 4-switch one is a standard reverser and the 1-switch one has the air supply on the middle and the two outer ports go to the input ports of the reverser (the middles of (...) (20 years ago, 10-Apr-04, to lugnet.technic)
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(...) Has anyone noticed all of the rich variety of parts available to the modern stud-free system that have no comparable equivalent in the old stud-dependant system? Take, for instance, these parts: (URL) triple liftarm> (URL) 1x2 flat liftarm> (...) (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books, FTX)
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| | Re: pneumatic cylinder: why not hydraulic ??
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(...) Cool, I look forward to it. I ended up adding two 1x4's per leg on my hexapod. They fit nicely. It looks very burly with all those switches though. All the structure and pneumatic parts are there, except hoses and T's. Hooking up all the hoses (...) (20 years ago, 10-Apr-04, to lugnet.technic)
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| | Whining about studless parts: was Pneumatics book?
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(...) (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books)
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| | Whining about studless parts - Was: Pneumatics book?
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(...) Can you really blame this on studless parts, given that many others *have* made worthwhile designs? Perhaps your prejudice against studless parts is preventing you from creating a worthwhile design. I have made a few worthwhile (IMHO) designs (...) (20 years ago, 10-Apr-04, to lugnet.technic)
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(...) I too regret the fact that studded designs are hard to find. There are plenty of situations where studded bricks are the way to go. Kevin (20 years ago, 10-Apr-04, to lugnet.technic, lugnet.books)
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| | Re: Whining about studless parts - Was: Pneumatics book?
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(...) I'm not sure how good an idea that is. Not the incorporation of BIONICLE parts thing, but the specific use of the socket joints. They're designed to work with friction, and I'd think that extended use of a motor would tend to wear them out (...) (20 years ago, 11-Apr-04, to lugnet.technic)
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(...) David, I'm not working on this issue because it is a good or bad idea, I'm on personal mission. I agree that that over time the friction would get reduced by wear. In fact though this wear will be a good thing. I have tried using gearboxes and (...) (20 years ago, 11-Apr-04, to lugnet.technic)
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(...) Hmmmm.... When talking about pneumatic gates in the past, I came to realize that different people defined gate inputs and outputs differently. Mark Tarrabain's single switch AND gate has two individual pressure inputs; one forces the piston to (...) (20 years ago, 11-Apr-04, to lugnet.technic)
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(...) I class the input as the position of each bank of switches. A bank of switches may be driven by one cylinder (1 or 2 switches), two cylinders (3-5 switches) or more (6 cylinders in the case of 9 switches in my octopus arm logic). The number of (...) (20 years ago, 11-Apr-04, to lugnet.technic)
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(...) Restricted as I understand it is not so much a question of how many different parts exist, but what different types of structures you can build from them. And given the great models I have seen in both TLG and MO creations, both studded and (...) (20 years ago, 11-Apr-04, to lugnet.technic)
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(...) Hi Mark, Is the cheapo ASCII art diagram below what you are talking about? We are viewing the switches/circuit from above. What is not shown is that the handles are all linked together. +-----+ +-----+ +-----+ +-----+ | | \ / | | | \ / | | \ / (...) (20 years ago, 11-Jul-04, to lugnet.technic)
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(...) The basic rule is that all tubes connecting two switch side ports must go to the same port on the two switches, to avoid leaks. You can see in your diagram that the diagonal connections don't do that, so they will leak. In a line, this is the (...) (20 years ago, 14-Jul-04, to lugnet.technic)
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