KB518: Locomotive Speed Matching

This article was last updated on Sept. 4, 2011, 10:54 a.m. | Print Article | Leave Feedback

Q:  I am trying to setup 4 Kato locomotives 3 SD-70MACs and 1 C-44-9, all with DN 163K1B decoders.  I am using the loadable speed tables V in the programing manual that came with my Super Chief for a starting point. I have spent a few hours with limited success. Do have any suggestions that may help simplify this process?

A:  Because the decoders and command control system are digital, the commands sent from the command station based on the CV settings in each locomotive are always the same.

It is the locomotive mechanisms that are different. Even with three "identical" locomotives from the same manufacturer, that were built by the same person on the same day, there may be big differences in the physical operation of the individual loco. One locomotive may have too much grease on the gears, or not enough oil on the bearings, or a small burr on one of the gears, all of which add up to differences in how each particular locomotive mechanism runs.

In addition you will find that individual locomotive operation changes depending on whether it has just been started up or if it has been running a while. 

This issue happens even with real locomotives, too. A group of MU'd locomotives may all be operating at Run 6, but unless all are pulling, there is lots of nosing and bumping going on as the locomotives travel down the track.  In earlier years, General Electric "Universal Series" locomotives has 16 power steps while other manufacturers only had 8 power steps. Of course, modern electronics has resolved a lot of the issues with earlier locomotive speed control, but when you watch a passing train that is neither accelerating or decelerating, there is bound to be some mismatched speed.

Here are a few suggestions

1.  Start with the slowest locomotive and match the other locomotives' speeds to that locomotive.
2.  You are right to be using the existing speed tables to begin the process of elimination necessary to get multiple locomotives to work together in harmony.

3.  Establish a starting point and then keep track of the changes you made to each locomotive's CVs.  This is a process of elimination so careful recordkeeping is a good thing.

4.  There is software available that may be helpful during this process.  Look for speed matching software on line.

5.  Be prepared to go back and adjust those settings after the locos have been running for a while.  You will notice changes as mechanisms wear during normal use.

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