07-11-2010, 10:18 AM
Weight in your cars won't improve track work.
Weight will improve our model car's suspension and track springing - if they have any. That's because it's relatively difficult to get model truck springs to work properly under a wide range of weights. So truck springs tend to be on the stiff side - Kadee sprung trucks being an exception in HO. So part of the NMRA RP weight was to encourage proper spring reactions of our model trucks. When our locomotives and cars have proper springing, the wheels equalize and can track over rougher track than with rigid frames. Which is one of the reasons why the prototype uses springs and equalization.
OTOH, modern production uses rigid frame trucks on cars almost exclusively. They are cheaper to make, and can have finer detail than sprung trucks. Track work is generally to a higher standard than it used to be decades ago, so springing and equalization aren't as necessary. With steel needle point axles turning in plastic or metal rigid frames on car trucks, adding weight increases the wear on the needle point bearing surface in the journals. Observe a Athearn car truck after many hours of running - especially if weight has been added to the car. You will see the the needle point has worn the journal, and the wheel set rides higher in the truck than it once did (you can detect this by observing that your couplers are low for no reason, when they were once on spec). Finally, modern plastic locomotives don't weigh as much as their die cast predecessors do. They can't pull as much. If space has been given over to the speaker and electronics, the locomotive weight is reduced further. So the advice not add weight to modern production cars makes sense, too.
So it really depends on your situation whether adding weight is a good idea. If you are using sprung metal trucks on a switching layout, and maximum length trains are not in the cards, weighting your cars to or beyond the NMRA RP is a good thing. OTOH, if you are running rigid plastic frame trucks on your cars and want to pull long trains with modern plastic engines, I would keep the weight to 3/4 or less than the NMRA RP. Just remember that the track work has to be a little bit better to prevent derailments.
my thoughts, your choices
Fred W
Weight will improve our model car's suspension and track springing - if they have any. That's because it's relatively difficult to get model truck springs to work properly under a wide range of weights. So truck springs tend to be on the stiff side - Kadee sprung trucks being an exception in HO. So part of the NMRA RP weight was to encourage proper spring reactions of our model trucks. When our locomotives and cars have proper springing, the wheels equalize and can track over rougher track than with rigid frames. Which is one of the reasons why the prototype uses springs and equalization.
OTOH, modern production uses rigid frame trucks on cars almost exclusively. They are cheaper to make, and can have finer detail than sprung trucks. Track work is generally to a higher standard than it used to be decades ago, so springing and equalization aren't as necessary. With steel needle point axles turning in plastic or metal rigid frames on car trucks, adding weight increases the wear on the needle point bearing surface in the journals. Observe a Athearn car truck after many hours of running - especially if weight has been added to the car. You will see the the needle point has worn the journal, and the wheel set rides higher in the truck than it once did (you can detect this by observing that your couplers are low for no reason, when they were once on spec). Finally, modern plastic locomotives don't weigh as much as their die cast predecessors do. They can't pull as much. If space has been given over to the speaker and electronics, the locomotive weight is reduced further. So the advice not add weight to modern production cars makes sense, too.
So it really depends on your situation whether adding weight is a good idea. If you are using sprung metal trucks on a switching layout, and maximum length trains are not in the cards, weighting your cars to or beyond the NMRA RP is a good thing. OTOH, if you are running rigid plastic frame trucks on your cars and want to pull long trains with modern plastic engines, I would keep the weight to 3/4 or less than the NMRA RP. Just remember that the track work has to be a little bit better to prevent derailments.
my thoughts, your choices
Fred W