To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.trainsOpen lugnet.trains in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Trains / 2939
2938  |  2940
Subject: 
Re: Building Bridges
Newsgroups: 
lugnet.trains
Date: 
Tue, 30 Nov 1999 19:22:43 GMT
Reply-To: 
[cmasi@cmasi.]StopSpammers[chem.tulane.edu]
Viewed: 
3677 times
  
Jeff Elliott wrote:

> In lugnet.trains, James Powell writes:
> > 
> > > 
> > > 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
> 
> 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, and I had to use a differential (barrel of it rotation-locked) to
> reverse the directions of the two drive axles so that both ends climb at
> the same time.  A side-effect was that I build an adjustment wheel onto the
> side of the differential that could adjust the height of one end with
> regard to the other by rotating the differential barrel.
> 
> Jeff Elliott

Jeff,

  Thanks for the idea for adjusting the height of one side of the bridge. I have
been using crown gears to send power to both sides of my bridge. When the dogs
kick it over it is a pain to adjust. You locked the drive axels together using a
1 stud long connector? (Sorry, I do not know the technic term for that little
piece.

Chris



Message is in Reply To:
  Re: Building Bridges
 
(...) 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, (...) (27 years ago, 30-Nov-99, to lugnet.trains)

22 Messages in This Thread:







Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR