Subject:
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Elevator alternatives
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Newsgroups:
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lugnet.robotics
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Date:
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Tue, 12 Jan 1999 20:37:34 GMT
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Viewed:
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1067 times
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John has an excellent point. Cables make excellent linear-drive
systems in Lego projects.
I was trying to build a large elevator a while back, and after trying
various solutions, I hit upon the following:
Use the chain linkbelt as a cable. Insert one end through rotation-
locked gears to fix it into place. Run the other end over the drive
gear.
Depending upon application, you can even close the loop in the chain
to provide tension over the drive gear.
The advantage of chain over a cable is, of course, that you can
tell precisely how far the chain has moved if you know your gearing
ratio - it works well with angle sensors and the like, whereas
actual thread or string varies a bit depending on how much you've
already wound onto the spool. Chain also doesn't slip in proper
designs.
As I mentioned, I used this in an elevator I made. The elevator was
a lifting platform with dimensions 32x32 studs. It used four closed-
loop chains, one at each corner, which were driven in parallel by a
pair of motors attached to my Control Lab. Since the attachment point
for the chain was slightly below deck level, the elevator deck was
higher than the lifting mechanism at its upper extent. This was useful,
as the intent was for the elevator to be part of a "hidden base"
for spacecraft, and was lifting craft from an underground hangar
up to the surface. The design allowed me to conceal all the lifting
equipment below the retracting roof, whilst the elevator lifted flush
with the "surface".
Jeff
John Scott Kjellman wrote:
>
>
> 2) If you are *really* trying to make an elevator, why not do it the old
> fashioned way? Most older elevators use a couple of pulleys and some
> steel cable. If you were to mount two pulleys on top of your elevator
> and two above the ceiling, you would thread some string through the
> pulleys onto a spool (made of a couple large pulleys) connected to your
> motor. I say to use multiple pulleys because it acts as a set of
> reducing gears, thus increasing strength and reducing speed. We
> wouldn't want your minifigs flying into the ceiling when they get to the
> top floor, now would we.
>
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Message has 1 Reply:
Message is in Reply To:
 | | Re: Worm Drive Question
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| Just to toss in my three cents (inflation adjusted to 1998 rates ;-) It seems there are two more options that might be a little easier: 1) My kids have gotten a couple of Lego sets that contain a long square shaft that has teeth on it. It mates to a (...) (26 years ago, 25-Nov-98, to lugnet.robotics)
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