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Subject: 
Tilting Train Movies: APT and Acela
Newsgroups: 
lugnet.trains
Date: 
Wed, 14 Nov 2001 17:43:07 GMT
Viewed: 
423 times
  
I have revisited the tilting train construction many times over the past
months.  I have been exploring designs mods for the model of the British
Rail Advanced Passenger Train (APT) as well as newly incorporating a similar
tilting mechanism into a model of Amtrak's Acela.

First, I must sadly report that I have opted-out of the simultaneous "lift
and tilt" design.  As the model of the APT developed into a full and more
proper configuration of 8 cars, the demand on the wheels/bogies to apply the
necessary force to both lift and tilt the car bodies caused a severe
increase in rolling resistance--particularly through extremely curvey-curve
sections of test track that were as long as the 8-car APT set.  Just too
much friction and binding between the train wheel flanges against the inner
track rails as the wheels are "pushed" into the track by the weight of the
cars.  To run the 8-car set in "lift and tilt" mode, I resorted to using
quantity three 9v train motors and quantity two speed regulators!  The
current draw from the three motors pushing-pulling the APT set was just too
great for a single speed regulator.  So, however poor of judgement it may
have been, I connected two speed regulators to the the track and dialed in
the same polarity and voltage position.  In this power configuration, the
full APT complement of 8-cars in "lift and tilt" mode worked
great!...however unconventional or unwise....

In an effort to require only one speed regulator, I have now opted to raise
the car bodies off the wheels/bogies by approximately 1-plate; perhaps
remeniscent of Eric Brok's original tilting Metroliner set(?).  I would like
to remind you that his design is an elegant inclined pivot that locates the
tilting axis at approximately floor level of the car bodies, just above the
bogie plate.   The APT now has a somewhat unsightly air-gap now showing
between the base of the car bodies and the top surface of the wheels/bogies.

In August 2001, I was extremely pleased to be invited by the PNLTC to
participate in their LEGOLAND California event.  I was graciously allowed to
run this 8-car version of the "air-gap" APT at the venue.  The 8-car set ran
on a fairly straight large oval of track without very many "curvey-curves"
on a single speed regulator.  However, I think I had taxed the three 9v
train motors too much, for at least one motor would "heat-out" and stop
working after a few tens of minutes of run-time; the APT set would just stop
dead on the track.

So, in the following movie of the "air gap" APT, I had to use two speed
regulators and three 9v motors.  Test runs using a single speed regulator
with the three motors yielded extreme slow-down through the most tortuous
curvey sections of track.  This MPEG movie is rather large at approximately
4.5MB; recorded at about 25frames/second, it is about 12 seconds long.

8-car "Air-Gap" APT movie (three 9v train motors and two speed regulators):
http://www.brickshelf.com/cgi-bin/gallery.cgi?f=6789

I have worked toward incorporating a similar forced-tilt mechanism into my
model of Amtrak's Acela train set.  The primary difference between the Acela
and the APT is that the Acela does not have shared wheelsets between the
cars.  I am having derailments of the Acela if I run it in "push" mode;
i.e., when the 9v motor is at the rear of the train.  (I am trying to force
the use of *only* one 9v motor.)  The forces exerted through the magnetic
couplers and the wheel/bogie axis of rotation cause the passenger car wheel
flanges to jump out of the track.  Also, the space-available in the
locomotive cab area is restricted if one build to allow a minifig driver
on-board.  This is a source of frustration in the tilt construction of the
locomotive nose of the Acela.  The following movie of the tilting Acela is
about 1.9MB, 25frames/sec, and about 5 seconds long.

4-car "Air-Gap" Acela movie (one 9v train motor and one speed regulator):
http://www.brickshelf.com/cgi-bin/gallery.cgi?f=3021

Thanks for reading, or at least "jumping" to the movies.  I hope they show
the tilting action well-enough.  Sorry about the file size and download
times for those of you with slow connections.  I know I feel your pain; my
modem connection speed from home where I upload the files is a snail-pace
21.6k.  Time for a coffee break.

later,
James Mathis



Message has 2 Replies:
  Re: Tilting Train Movies: APT and Acela
 
(...) It is always a pleasure seeing your handiwork, James, and even more so in motion:-) The tilting action is terrific; you can really see it on the APT (less so on the Acela-- slightly different camera angle?) It is an engineering masterpiece. (...) (23 years ago, 14-Nov-01, to lugnet.trains)
  Re: Tilting Train Movies: APT and Acela
 
Hi James, I have gotta say - that APT is extremely good and very authentic looking - not just the tilting action but the overall appearence of the model. Being originally from England, I had the pleasure of seeing the real APT a few times hurtling (...) (23 years ago, 15-Nov-01, to lugnet.trains)

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