55848Re: Turnout Derailment
- Mar 1, 2008Hi Andy;
The "back to back" measurement of a wheel set is the distance between
the back fo the two wheels located on teh same axle. THis distance
has to be slightly larger than the distance between the inside of the
guard rails on the inside of outside rail and the one on the inside
of the frog. So you are checking whether the flange of the wheel set
can pass through this tight clearance without binding. If the wheels
are too far apart the flange will climb the point of the frog and if
they too close together and the wheel will climb the bend in the
point rail where it transitions to be come the guard rail for one
side of the frog.
It is not uncommon for a car to roll through the switch without
derailing when going through on its own as one wheel at a time can
climb the tight spot and return to the track. IF you watch closely
you can see the car and truck bumb over the tighness. The most common
cause is being too tight as being to wide will cause problems
elsewhere in the track work. The marklin wheels can be moved on the
axle but you need to realize that it may not require a movement of
more than a 32nd of an inch or even a 64th of an inch to solve the
Micro Trains makes a coupler height gauge Part No. 920 in the old
numbering system which will also function as a track gague and a
wheel back to back gauge. Some of us have a back to back gauge made
of brass or aluminum that looks something like a horseshoe which we
can slide between the two wheels on an axle to set them for the
correct back to back distance.
Hope that helps you
--- In email@example.com, Andrew Poulo <apoulo@...> wrote:
> Hi Garth,
> Thanks for the response to my question, but I'm not sure I
> what you mean by the "back to back on the Marklin wheel sets." Let
> also give you some additional information. I have a variety of
> American freight and passenger cars. If allowed to roll through the
> turnout alone, every car will make the turn smoothly. If coupled
> together in any conceivable combination, the second car will always
> fail to make the turn because of what you describe as a wheel pop.
> Any additional thoughts?
> Andy Poulo
> On Feb 29, 2008, at 7:23 PM, Garth Hamilton wrote:
> > I would look closely at one car going through the turn out and you
> > might find that the back to back on the Marklin wheel sets of the
> > problem car is too small or tight and the wheel set can not pass
> > through the two guard rails. This usually causes a wheel pop up
> > guard rail beside the frog.
> > regards
> > Garth
> > --- In firstname.lastname@example.org, "apoulo" <apoulo@> wrote:
> > >
> > > I'm new to the group and relatively new to z scale. I am
> > experiencing
> > > a problem running Marklin cars over MTL turnouts. The problem
> > > occurs on right hand turnouts when making a right hand turn.
> > > cars derail a high percentage of the time while MTL cars have
> > > problem. My guess is the problem lies with the Marklin
> > > think the coupler of the first car is exerting an outside
> > on
> > > the following car, causing it to want to go straight and
> > > switch.
> > >
> > > I'm not sure my analysis is correct, and even if it is, I can't
> > figure
> > > out a solution. Has any one else experienced this problem, and
> > > any one have a solution?
> > >
> [Non-text portions of this message have been removed]
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