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Subject: 
Re: Some help or advice requested
Newsgroups: 
lugnet.technic
Date: 
Wed, 27 Jan 2010 08:59:54 GMT
Viewed: 
32709 times
  
In lugnet.technic, Kevin L. Clague wrote:
> In lugnet.technic, Kevin L. Clague wrote:
> > In lugnet.technic, Owen Dive wrote:
> > > In lugnet.technic, Kevin L. Clague wrote:
> > 
> > <snip>
> > 
> > > Hmm, an interesting solution.
> > > >  Presuming you can do that, then all
> > > > you have to do is somehow get the weight back to the starting position.
> > > 
> > > But there's the rub! I'm afraid I can't see an obvious way to do that, given
> > > that the weight will need to be positioned quite precisely. I will play around
> > > with it, though, and see what I can come up with.
> > 
> > I've got a slightly different solution, where the tray tips an inverted pendulum
> > right and left.  The pendulum's momentum/weight flip the polarity reverser.
> > 
> > The tri-blade bounds the inverted pendulum's swing.
> > 
> > The first three steps represent the basic inverted pendulum.
> > 
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4312628
> 
> Direct access:
> 
> http://www.brickshelf.com/gallery/kclague/fun/fun_page_1.png
> 
> > 
> > The yellow beam added in step 2 is the inverted pendulum (on which you can add
> > your favorite weight attachment).
> > 
> > In step 4, you can limit the range of motion of the inverted pendulum (if you
> > wish).  Other limiting devices (8T gear, 1/2 bushing, etc.) can be used instead.
> > 
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4312629
> 
> Direct access:
> 
> http://www.brickshelf.com/gallery/kclague/fun/fun_page_2.png
> 
> > 
> > I don't know if the tray's slow progression right and left can eventually tip
> > the inverted pendulum past center (it depends on if the inverted pendulum can
> > reverse the tray's travel)..... but if it can it might help.
> > 
> > Kevin
> 
> Kevin

A nice solution, but I doubt very much if my tray could push the pendulum
upright (especially since the total angular travel would be the limited movement
of the pendulum _plus_ the angle that the tri-blades had rotated). However, for
situations with more force available (e.g. a tray propelled by gears meshing
with a long rack**) it would work very well. I shall keep it in mind for future
projects!

Thanks!
Owen.

** I did experiment with this kind of set-up, but couldn't find a way to make
the tray travel two studs exactly (5 teeth of a rack) and then pause for a bit.



Message is in Reply To:
  Re: Some help or advice requested
 
(...) (URL) (...) (URL) (...) Kevin (17 years ago, 26-Jan-10, to lugnet.technic)

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