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Subject: 
Re: motorized points - beating a dead horse
Newsgroups: 
lugnet.trains, lugnet.robotics
Date: 
Sun, 3 Dec 2000 05:33:06 GMT
Viewed: 
350 times
  
Great tip, I never thought about using multible pulley/rubber bands! A big
problem is the detent, the two at rest positions are very "sticky". Naybe
more then multible rubber bands can even move. I'll give it a try.
SteveB

In lugnet.trains, Juergen Stuber writes:
> "sebarile-MOBL" <steve.e.barile@intel.com> writes:
> > 
> > Currently I am attempting to build an automated hump yard. The main problem
> > I'm tackling is the RCX controlled motorized points. I've spent 7 hours over
> > the last two days trying to build a motorized switch track that will run
> > forever with out ripping itself off the base plates and be very *forgiving*
> > at the edges of both states, turn or straight. What I mean by forgiving is
> > that the motor doesn't burn up or the gears do not get stripped off.
> > 
> > I like really simple and elegant solutions. For instance I would like to be
> > CPU switched with no feedback, again forgiving at the edges of both states
> > such that the motor can spin for 1.5 secs and not reap havoc. Hanging
> > elaborate clutch systems with differentials and angle sensors would not be
> > my first choice. Of course beggers can't be choosers.
> 
> I'm not exactly sure about your setup (I'm not into trains),
> but how about a small pulley (half bushing) on the motor,
> driving a medium pulley (with the six holes) on an axle on
> whose other end is an 8t gear that drives a rack.
> That setup works well for rack and pinion steering,
> where you have similar problems.
> If one pulley/rubber band is not enough you can put another one
> in parallel (like in 8480), or you can experiment with the tension
> of the rubber bands.
> 
> Jürgen



Message has 1 Reply:
  Re: motorized points - beating a dead horse
 
(...) I made a design that used a clutch gear and fit into a house. It worked very well when the switch was "warm" but wouldn't always trip it when it had been sitting for a bit. But it allowed the throw arm to fully though the switch one way or the (...) (26 years ago, 3-Dec-00, to lugnet.trains, lugnet.robotics)

Message is in Reply To:
  Re: motorized points - beating a dead horse
 
(...) I'm not exactly sure about your setup (I'm not into trains), but how about a small pulley (half bushing) on the motor, driving a medium pulley (with the six holes) on an axle on whose other end is an 8t gear that drives a rack. That setup (...) (26 years ago, 2-Dec-00, to lugnet.trains, lugnet.robotics)

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