Momentum FA2

[steelrail]

Can the momentum be changed on the FA2 ? If so what CV ? Mine jumps with each speed step change , not smooth at all. Thanks .

[richg]

Read the document for this loco. You can download it from the Bachmann site.

Rich

[richg]

What brand DCC controller are you using? Check your manual.
You really need to post more info when you have a question. Helps with troubleshooting.

All I know is that your DCC controller sets the momentum. My NCE Power Cab has momentum, up/down buttons.

Anytime I have an issue with a decoder, I do a decoder reset and go from there.

Rich

[steelrail]

It's the factory decoder in the Bachmann FA2 , a budget soundtraxx I believe , and a Prodigy express.

Many decoders have 2 CV's that can be adjusted for "momentum". One adjusts how fast the loco reaches the selected speed. Rather that instantly jumping to the selected speed as mine does the loco will slowly (depending on the value programmed in ) build up momentum until it  reaches the selected speed. The opposite for braking is programmed into the second CV .

I was just wondering if this is available in these decoders as the basic info provided with the loco and the sheet available here do not seem to list CV's for momentum.

[jward]

the cvs you want are cv3 and cv4. in all the bachmann decoders i've run across these are supported.

here are the 5 most important cvs for controlling the operating characteristics of your locomotive.


CV 2 - Start Voltage: Set this CV to adjust the start voltage so that the engine starts moving at speed step 1.
CV 3 - Acceleration rate (momentum)
CV 4 - Deceleration rate (momentum)
CV 5 - Maximum Motor voltage: adjust top speed
CV 6 - Mid Range Motor Voltage: adjust speed curve

note that not all bachmann decoders support cv5 and cv6, but they do support the others.

[steelrail]

Thanks jward, CV 3 and 4 it is! Value of 25 in CV3 and 20 in CV 4 and she's now as smooth as glass .

[ebtbob]

Good Morning all,

      The use of the term "jumps with each speed step" suggests to me that the engine is set at 28 speed steps.   Instead of changing momentum to solve that,  try to get the decoder in the 128 speed step.   

[steelrail]

ebtbob,

128 SS is the first thing I tryed, helped but still a noticable jump with each speed change . I have a small layout so I run short trains at slow speeds. Mostly the lower half of the throttle range so 28 SS is better choice for me. Tweeking the momentum CV's smoothed every thing out and allows me to use the 28 SS setting .

[bapguy]

Down load the Soundtraxx Diesel users guide from their web sight. One thing to try is to program the decoder to use a speed table. I think it's CV25. There are 15 factory ones pre set and a user adjustable one. Also if your lay out has a continous run run the loco in one direction for about 20 minutes at slow speed. Increase the speed to half and run 20 minutes or so. Then run at top speed or close to it for another 20 minutes. Repaet the above running the loco in reverse. This helps break in the drive train. I use a Digitrax PR3  with Decoder Pro to program my Tsu decoders. I set up a speed curve to limit the top speed. This is a great program to use.  Joe.