My understanding of fly wheels is that they allow engines to coast to a stop rather than stop on a dime. I have a Berkshire in the Pocono set (6-81025) that stops abruptly, forwards and backwards, kind of like early Williams by Williams engines. Is this normal? Can this flywheel or motor be adjusted to come to a coasting stop?
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Do you have a Legacy remote? Momentum can be adjusted using the buttons at the bottom.
Mr Lucky, this is strictly an old school transformer powered set from about 2015.
Just reduce the voltage using the handle and you won't have the quick stops. Some electronics do what you see, the MTH PS/3 boards are rather famous (or infamous) for this issue.
The flywheels in Ogauge trains are simply too small for a coasting stop. I think they are mostly there for tach readers etc. Just no room for huge flywheels like used in HO scale. Momentum and voltage are the best for smooth stops.
It’s a matter of flywheel size as a ratio to locomotive weight and the complexity of the mechanism (with most diesels driving a minimum of eight wheels).
I have an MTH Docksider that coasts as much as a foot after power is suddenly turned off. But that mechanism is very simple, driving only the two front wheels of the 0-4-0 wheel arrangement.
Please correct me if I'm wrong, but isn't the Pocono Berkshire "Jr" as described in the catalog and the original Polar Express (2004) the same engine minus some cosmetic differences like the enlarged pilot on the PE? My PE coasts nicely despite having the cheesy Series I motor. FWIW, minimum curve on the PE is O27 and the Pocono is O36. I can attest that both run just fine on O27.
Like I said, the coasting distance can be as much about the electronics driving the motor as it is about the flywheel size or weight.
As Jim mentions with the Docksider example above, a large flywheel CAN confer meaningful coasting, if the electronics will allow it. (Jim- your docksider has both axles powered, they are connected through the drive rods.) How much depends on the diameter of the flywheel, the GEAR RATIO, whether the gears are back-drivable, etc.
To the original poster: the Series I Berkshire Jr from 2004 have a smaller motor (with weaker magnets?) and a larger flywheel. When Lionel started getting them back for repair with burned-out motors, they substituted a larger motor. Unfortunately, that left very little room for the flywheel on top. It would have been better if they put the motor in the firebox area where there's plenty of space. Then, there would still be enough room for a good-sized flywheel. Given the way it's designed and the available space, I don't think you'll get more coasting out of your Pocono Berk unless you revert to a Series I chassis (and then don't abuse it by pulling too many cars.)
@Ted S posted:(Jim- your docksider has both axles powered, they are connected through the drive rods.)
Yes, but the simple side rod action combined with non geared wheels provides less resistance than if the second set of drivers was turned by a gear. The drive wheel turns freely if you unhook the side rods.
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