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(...) The way Doug explained it, it's the beginning of a pick and place machine. What you see in the pic is accurate in the X and Y, he hasn't done the Z yet. The structure is surprisingly rigid. Almost no flexture. -Rob. (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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(...) That's because it's a truss :-) A truss is a structure composed of triangles (very simple explaination). A truss is very stiff because its geometry causes all members to be loaded in compression or tension. Theoretically, the members see no (...) (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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(...) In practice, given the length of the members in Doug's model I'd expect them to behave as slender columns when loaded (by leaning on it as opposed to the weight of the pick n place mechanism which didn't seem to add much load). -Rob. [looking (...) (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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(...) And those would be the compression members of the truss. (...) At just a glance (i.e. no proper analysis), I imagine that when you "leaned" on it, you'll have a few members in tension somewhere in the structure. The structure will deflect very (...) (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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(...) I'm guessing the members would delaminate (the plates capping the double beams would separate) especially if the loading is cyclical. I still think a long column will describe the behaviour more so than a truss because of the length. I don't (...) (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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(...) You're comparing apples to oranges here. Within a truss, you will have members in compression. Column analysis (i.e. Euler buckling, and the like) can be applied to those memebers. To say that it behaves more like a slender column than a truss (...) (22 years ago, 26-Jul-02, to lugnet.robotics)
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| | Re: My Pictures From Brickfest
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"Rob Doucette" <lego@nospam.doucettenet.com> wrote in message news:Gzu367.59n@lugnet.com... (...) device (...) type (...) That's not really right - there are no typical "X Y Z" axis designations when dealing with this style of robot. The robot Doug (...) (22 years ago, 27-Jul-02, to lugnet.robotics)
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| | Delta Robot Information
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First off, let me say that my respect for Iain has never been greater. He has got to be the resident expert in robotics, and really pushes the envelope as to what can be built out of Lego. He builds models of insane robots that I have never even (...) (22 years ago, 30-Jul-02, to lugnet.robotics)
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| | Re: Delta Robot Information
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Just want to add my thanks to Iain as well! Both for the wonderful description and links as well as the inspiration for building a Delta robot in the first place. 'Tijs' was just so cool that I had to try my hand at building a Delta robot too. :-) (...) (22 years ago, 30-Jul-02, to lugnet.robotics)
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