The Shell Game / Speed Matching DC units

Greetings All,

I recently watched fellow modeler Roy Smith's four part speed matching videos on Youtube. Roy is an N scale DCC modeler and produces a couple of videos a week on his Union Pacific Evanston Sub channel.

This prompted me to examine some of the engines in my own fleet that were not consisting as well as I thought they should. 

Being a DC modeler, speed matching mostly consists of swapping shells to achieve the results you want. For this project I dug out my various Bachmann units and mixed and matched the shells to achieve my goals of smoother running and quieter consists. Before doing that an inspection for loose wires, a wheel cleaning and maybe a lube job should be considered. This was the culprit on one of my NYC F7As.

Once you've decided your engines are in good running condition evenly space them on a track and run them back and forth several times. 

The PRR A-B-B-A are Bachmann Plus units. I bought an A-B set new from Trainland in the 1990s and an A-B set used on ebay just a few years ago. The second A unit was a dummy when purchased and here I swapped the F7A shell onto a powered B unit chassis. The F7B got the unpowered chassis. This way I can have a power unit on either end of the engine consist. I even added the headlight and figures! 

Mixing and matching my FT A-B-B-A units with F7 A-B-B-A units gave me two smooth running consists. However one of the Bachmann blue box FT B units was way too fast for either consist making the FT an A-B-A set as seen below.

This Bachmann Plus NYC A-B-B-A set has swapped a slow B unit for a the slightly faster FT B unit from above. All units in this consist are now running smoothly together.  

On some consists I've noted a grinding sound that I'm fairly certain is not the dynamic brakes.😉 I think what's happening is a unit (or two) is significantly slower or faster than the the other (s) and the noise is from the motor trying to keep up with the speed of the axles or being dragged along. 

Such was the case with this Bachmann Plus NYC F7 A-B-A set. I've swapped shells from a PC F7A with the NYC F7A to get this A-B-A consist running smoothly. B.T.W. This seven unit lash up ran very well together!

These were the easiest engines to speed match. All are unpowered! The three F units are old pancake motor train set units that I've painted and made into free rolling units.

Next I swapped shells on my GP30 fleet separating the made in China engines from the made in Hong Kong engines. Here's an engine lash up that surprised me by running very well. Two made in China Bachmann Spectrum GP30s and a Bachmann blue box F7A ran silky smooth together. F7A #1602 and the GP35 are non powered. 

Lastly I turned my attention to a long annoying Proto 1000 
C-Liner A-B-A set. They ran very well in the A-A configuration but that B unit was too fast. I pulled out their circuit boards a long time ago and hardwired them. They ran better but the B unit was still too fast.   

Then I had an AHA! moment. Maybe if I put a light bulb in the B unit it would draw the same as the bulbs in the A units and slow that B unit down a bit. 

And wouldn't you know it actually worked!! This A-B-A set is now running smoothly and quietly! I imagine a resistor would work as well but I had the bulb on hand and went with that.

So after spending a couple of hours in the train room I was happy to end up with some smooth running consists. 

Here's a short video of the project engines.

Thanks for reading and watching!!!
I'll be back on Friday October 18th for the start 
of the P.C.C.M. 65 series.
See ya then!!