In the process of establishing the nominal freight car, the rolling characteristics are also an important consideration. In HO, metal wheels are clearly the favored type. Based on my limited experience in N scale, it is not clear what is the dominate choice. To help understand this issue, a couple of examinations will be pursued.
A specific car will be examined for rolling characterists.
- First it will be run with a generic truck & plastic wheels
- The wheels will be switched to metal wheels
- Then the trucks will be changed to MTL Berber trucks with plastic wheels
- Finally these wheels will be changed to metal wheels.
The process will be to measure the car velocity in SMPH a specific distance from the starting point on a 2.5% grade. The time it takes to roll that distance will also be recorded. The will be repeated for a number of cars.
A car with the generic trucks is shown here:
A car with the generic trucks & metal wheels is shown here:
A typical car with the MTL berber trucks is shown here:
A typical car with the berber trucks & metal wheels is shown here:
These are ESM wheels that had 0.54 in axles. Indeed they fit really well in the MTL trucks. These wheels are shown here:
The testing may be expanded to include other manufacturer metal wheels with potentially longer axles. This will indicate how much that influences the results.
Also determined will be the respective car weight changes. In the only case so far, switching the plastic & metal wheels on the MTL trucks increased the car weight form 14 grams to 16 grams. Which is 14%. This activity will shed some light on the benefit of adding that weight to the cars.
The first two parts of this study is to prepare my test track and to select a set of appropriate cars to use for the examination.
My test track consists of a 2 x 8 section with five sets of HO track. The center of these has been replaced with a Set of Atlas code 80 N gauge track. The initial examinations were done with the track just laid on the board. My speedometer has been set up to measure HO engines with weights affects to the roof. This leads to a problem with the N scale rolling stock because it is to low for the Speedometer to see.
The solution for this problem is to get is to raise the N scale track so the meter will see it. I want to use this test track for my clients engines, be they be HO or N scale.
It appears that a 1/4 inch will do. Lowe’s has a PVC strip that is 1/4 x 1 1/2 x 8’. So that is the direction that will be followed for now. It may require two, will be verification tests to be sure it will work as needed.
The selection of the cars to look at is address in the following:
For now the three cars will be used for the base set for this study.
The 1/4 x 1 1/2 x 8’ PVC plank arrived and the 1/4 inch was enough to allow the speedometer to see the N scale rolling stock. Before I call it a success, the HO test section will be tested to be sure there is no interference. If all goes well the plank and N scale track will be put in place with chalk.
This study will be on going for a while. additional journal entries will be added as appropriate. Come back often.
