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Hey there folks, recently my eyes were opened to the mechanical possibilities that the Lego pneumatic systems allowed and today I received my Bricklink order for a couple pumps, pistons, switches, airtanks, and tubes and have been happily testing (...) (21 years ago, 23-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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Hi Brian, Have a look to Kevin's presentation: (URL) it doesn't answer all of your questions, but at least to point 4: use a small piece of tube and plug in a minifig tool handle or a bar such as (URL) (21 years ago, 23-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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In lugnet.org.us.lugola, Brian Reynolds wrote: <<snip>> (...) The hoses will pop-off before any damage is done due to preassure. The preassure will also leak out in time so there's no danger there either. (...) Depends on the compressor. (...) Don't (...) (21 years ago, 23-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) By highly scientific methods [1] I got ~54N, beyond that the cylinder starts leaking. With a diameter of the piston of 13mm that gives 54N/(pi*0.0065mm^2)=406833.94 Pa ~ 4 times atmospheric pressure. That is rather new transparent cylinder (...) (21 years ago, 23-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) My friend Doug has used them up to 30 PSI. (...) I don't know what the maximum allowable pressure is, but 30 PSI is probably a good upper bound. It depends on which direction you are trying to move the weight. If you are trying to move it (...) (21 years ago, 23-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) Thanks for the heads up, that presentation really does help out quite a bit and the outlet plug is also a good idea. I'm awfully surprised that there is no official outlet cap after all these years, but I suppose that Lego never felt one was (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) That's good news. My interest is in building full-built models and not the technic see-through style efforts that I usually see the pneumatics used on so it'll be important that the cylinders are capable of moving the combined weight of the (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) What I'm currently thinking about is a mechanisim that will move an arm that's hinged at one end through a near 180 degree arc before it comes to a rest and then to have the reverse switch pull the arm back to it's initial position. At one end (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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Tobbe Arnesson wrote: > The hoses will pop-off before any damage is done due to preassure. The preassure > will also leak out in time so there's no danger there either. I verified this for myself tonight with three pumps working three airtanks and (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) Near 180 degrees maybe tough. You'll need to keep the piston attached as close as possible to the pivot point of the arm to get the maximum range. <snip> (...) Thanks for the positive feedback. I have three large pumps all attached to the same (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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(...) Levers are your friend! Have a look at the mechanisms used to drive the buckets on 8455 backhoe (front and back), and similar models. While these operate nowhere near 180 deg, adjustment of lengths/fulcrums may well get you closer. ROSCO (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) The four bar linkages used for driving excavator buckets are good for doing appoximately 180 degrees motion, especially when you have to go "round a corner". The following shows an example - I'm not sure about its angular range but certainly (...) (21 years ago, 25-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) I'm not sure and my bricks aren't around as I type this; Does the 1 x 1 technic brick [1] (or similar) slide over the hose end when it's connected? If so that should make a real snug fit for the hose. Perhaps some other brick can do this (...) (21 years ago, 26-Sep-03, to lugnet.technic)
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(...) For models with a lot of cylinders I use a car tyre air compressor. I bought the slightly more expensive one tha has a variable pressure limiter and set the limiter to 20 PSI initially. This wasn't quite enough. 25 PSI was good for all but the (...) (21 years ago, 26-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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(...) [snip] (...) Thanks! (...) Mark Terrabain invented a single piston, single switch AND gate, but it only has one pressure output, so you have to retract the pistons with some external force like rubber bands. I invented a single pison, dual (...) (21 years ago, 26-Sep-03, to lugnet.org.us.lugola, lugnet.technic)
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(...) Ack! Sorry for duplicating your message there Rosco, my NNTP connection to lugnet has been a bit flaky recently which confuses me greatly. I've had a message dissappear as well, is anyone else experiencing NNTP woes? Jennifer (21 years ago, 26-Sep-03, to lugnet.technic)
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(...) I've said it before (several times :-) and I'll say it again: since the airtanks cannot provide consistent performance levels, in my opinion they are rubbish for most applications. You are far better off building a motorised compressor that (...) (21 years ago, 26-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) This post explains the recent wonkyness with Lugnet: (URL) (21 years ago, 26-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) Which explains why I got 34 messages after only being gone since yesterday morning... ~Mike (21 years ago, 26-Sep-03, to lugnet.technic)
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| | Re: Lego pneumatic systems overview?
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(...) No problem Jen. And you did value add with the link, I think that counts as extra information ;) ROSCO (21 years ago, 26-Sep-03, to lugnet.technic)
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(...) Don't know about 'beauty', but my dancing Easter chickens were popular at work: (URL) ran them off the compressed air coming out of the wall (in a hospital), and I had to turn the pressure way down to keep them from boucing apart... (18 years ago, 10-Jul-06, to lugnet.org.us.lugola, lugnet.technic)
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