Subject:
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Re: Building Bridges
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Newsgroups:
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lugnet.trains
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Date:
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Mon, 29 Nov 1999 00:24:07 GMT
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Viewed:
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1382 times
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>
> Lift Bridge. I'm actually on my second version; the first was lifted by
> long chain-link chains and powered from the top of the towers. It only
> carried a single track, and the deck was quite light, and a little flimsy.
> I ran into difficulty with the fleixibility - when the centre of the
> bridge depressed (eg: when the engine got there) the tips of the bridge
> would rise slightly - enough to derail the car that was passing over,
> at high speeds.
>
> The current edition is very stiff, carries two tracks, and uses a rack and
> pinion system at each end to crawl up the towers.
I'm using strings, and have problems with them not winding evenly. This then
causes one side or another to be higher than the other. End to end isn't too
bad, but I did not leave in any way to ajust a single string save much hassle
at one end...stupid, but it works for now, and I doubt I will change it until I
have to move in about 15 months.
(It kind of sucks, when you start thinking in those terms, and i have only been
living here since sept)
My deck is quite flexable, and I have had problems with it breaking apart with
repeated movements. To make things a little worse, one end is on a curve...not
the best idea, but I had no choice in the matter.
> Largely because of the social situation - this layout is at work, and the
> people there are more careless than I am. They're prone to run the train
> too fast, or run it with the bridge up (!), etc. I want a fail-safe to
> ensure the train doesn't go too fast, and that it only moves with the
> bridge down. I've considered using an all-mechanical system, but I might
> want to use the robotics features later, to handle automatic stops, etc.
I can understand why if mindstorms is the train controller in total. That
makes more sense. I have mine semi mechanically interlocked, you have to move
the power from the bridge motor to the track to run a train. This prevents
-unknowingly- running into the open bridge. It won't stop someone who is
determined, but that's OK in my use. (I supervise use of the bridge)
This is a prototypical fault, you could warn people till you are blue in the
face, and every now and then, someone would drive right into the river...
James Powell
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Message has 2 Replies:
 | | Re: Building Bridges
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| (...) Hee Hee This reminds me of the original Adam's Family. Gomez and his trains. I would imagine a Lego crash would be much more ... ummm...entertaining(?) than an HO scale train crash, of course leaving out the explosives<grin> or not ..... John (25 years ago, 29-Nov-99, to lugnet.trains)
| | | Re: Building Bridges
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| (...) If you use the chain links, you don't get the offset problem. Drape them over a driving gear and let the tail ends hang free (ie: don't wind them up) That version of the bridge was powered from the centre of the connecting truss at the top, (...) (25 years ago, 30-Nov-99, to lugnet.trains)
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Message is in Reply To:
| | Re: Building Bridges
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| (...) Lift Bridge. I'm actually on my second version; the first was lifted by long chain-link chains and powered from the top of the towers. It only carried a single track, and the deck was quite light, and a little flimsy. I ran into difficulty (...) (25 years ago, 28-Nov-99, to lugnet.trains)
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