Subject:
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Re: How much weight can a LEGO chassis carry around?
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Newsgroups:
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lugnet.robotics
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Date:
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Sun, 11 Dec 2005 18:22:27 GMT
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Viewed:
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5075 times
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Those master RCX groups could always have their motor outputs setup to
perform the act of pushing the on buttons on the other RCXs. The
alternative would be a large mechanical switch mechanism made that
could be operated, pushing levers down to press the RCX buttons. You
would need a lot of levers, and many interconected beams to do it, but
its possible
There is always a way around things, even if they are a bit awkward.
Of course here we are already including a Laptop, so while I might use
Lego in some cases, in a situation where I wanted to mount a laptop, I
would start to consider more the concept of using non-Lego components
in the setup. I would probably not mod the Lego, while I can, its a
little too valuable to me to do so. I would really love to have casts
of aluminium pins, studless beams, and large plates with studless beam
style connectors and lego dimensions. Maybe I could try to cast
something like it from white metal (used in miniture casting) some
time - although I am not sure how its tensile properties compare with
ABS.
--
Danny Staple MBCS
OrionRobots
http://orionrobots.co.uk
(Full contact details available through website)
On 11/12/05, steve <lego-robotics@crynwr.com> wrote:
> The answer to the question "How much weight can a LEGO
> chassis carry around?" has got to be "Infinite" (assuming
> that you have infinite amounts of Lego as some people
> here appear to have!).
>
> How's this for a thought experiment:
>
> Build a perfectly square synchro platform with four wheels,
> two motors (one for driving and one for steering) and
> an RCX to control them. Let's toss in two rotation sensors
> so the RCX knows how fast it's driving and in what direction.
>
> That's not rocket science - there are lots of examples of
> people having done that.
>
> How much weight can it carry? Let's say 1 pound - it's
> probably more - but let's be conservative.
>
> Now - suppose you want to carry 100 pounds.
>
> Well, you just build 100 of those units and connect them
> up in a 10x10 square. We can set them up so that one
> 'master' RCX issues speed and direction commands via IR
> so the whole monsterously large mechanism is driven from
> one source.
>
> Because you have a regular grid of these units, the
> load can easily be distributed fairly amongst them
> by building a suitable platform on top of them. The
> forces between them as they drive will be close to
> zero and therefore the interconnecting structures
> will be lightweight and very easy to construct.
>
> This system scales perfectly until the robot is so
> large that the furthest unit from the center is out
> of IR transmission range of the master RCX. But
> even that can be handled with a relay transmission
> scheme.
>
> The only drawbacks to this thought experiment are
> that the relaying of IR commands would slow the
> robot's manouverability because of the time taken
> to repeat the command to every RCX - and the
> theoretical problem of keeping them all synchronized.
>
> There is another practical drawback.
>
> Suppose you wanted to build a Lego robot that could
> carry a car. (say) a 6,400lb carrying capacity.
> You'd need a 80x80 grid of synchro platforms - each
> with an RCX's.
>
> Such a machine would probably be 40' long x 40' wide
> and about six inches tall - so you'd need a relay of
> perhaps 64 more RCX's to pass the IR commands from
> a master RCX controlling the whole machine.
>
> You'd have to build a pyramid under each wheel of the
> car to spread the load evenly - but this is definitely
> do-able if you had enough Lego.
>
> Here's the problem though.
>
> When you came to turn the entire machine on (all
> 6,481 RCX's - then even if you went through the machine
> turning one RCX on and starting it's program every
> second, it would take you almost two hours to get
> them all running - so the odds are good that the first
> RCX would be out of battery power by the time you'd
> turned the last one on!
>
> ...but that wasn't the question.
>
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Message is in Reply To:
 | | Re: How much weight can a LEGO chassis carry around?
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| The answer to the question "How much weight can a LEGO chassis carry around?" has got to be "Infinite" (assuming that you have infinite amounts of Lego as some people here appear to have!). How's this for a thought experiment: Build a perfectly (...) (21 years ago, 11-Dec-05, to lugnet.robotics)
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