Monthly Archives: October 2015

First cut at the impact of a can motor and DCC module

As a part of the motor variation series that is currently under way, a number of items will be examined in a one-off manner for the most part. The number of variables is such that a classic DOE is beyond a reasonable possibility.

A reasonable set of results can be achieved by keeping all but one element constant in the tests. These increments will be repeated as the testing goes on in different engine models, types and manufactures.


These tests will be run on a standard DC power supply. The purpose here is not to evaluate the variations of DCC modules or sound programs. The only impact that will be recorded is how the various featured impact the engine operation on DC power.

The first two sets have completed testing. The first is an Athearn blue box Amtrak F7A engine. For this engine, four discrete rests were performed.

1.- stock BB parts.

2.- Can Motor trucks & drive shaft replaced with P1K F3A parts

3.- 2 with a NCE DCC decoder added.

4.- 2 with a NCE card decoder added

4a.- 4 with CV’s tweaked to see if they impact the DC performance

The second set deals with a P2K B&LE SD7 engine

In this case, the engine was not running when received. The fault was the light board electronics were not allowing the motor to run. For this set a limited set was examined:

1.- the stock components were wired to run without the light card electronics. It would have been nice to get a direct evaluation of the light card impact, but a SD7 card was not available.

2.- A NCE DCC card decoder was added to 1.

The first set gives a first cut at the difference between a BB rectangular open frame motor and the P1K can motor. In addition, the DC performance impact of adding a DCC module is identified. While it is known that there is a maximum voltage loss in DCC, the voltage loss of having the decoder in the circuit is seldom discussed. Because of the first result, a second decoder was included. After the results showed to be similar for the two decoders. The CV’s were tweaked to be sure that was not the reason. It was not.

This posting will be updated with the appropriate graphics as they become available over the next week or so.

The second engine shows the performance characteristics of a P2K engine without the light card. While this engine was not run with a light card in this series, the data can be compared with the other P2K engines that have been tested here. There should be some interesting information gained here.

Life Like Building kit

light signal kit

NCE D13SRP decoder

The second part of this engine tests is adding another NCE DCC decoder to the engine. Thus is a different decoder than tested above. It will be interesting to compare the two results.

Again, there have been several other engines tested with a DCC decoder in place. Those will be compared as well.

Again, as these comparisons become available, this post will be updated.

The series is leading to some interesting results. As indicated, the plan is to repeat some of these increments to provide some statistical relevance.