Speed Matching Soundtraxx Decoders
Speed matching is extremely vital when operating helpers on a model train provided you do not have a second or third operator to assist with a throttle. If you do not have the speed matching perfectly calibrated, you will end up with irregularities while operating your train.
It is vital that motive power is precisely speed-matched so that you do not have any in-train forces that will cause a derailment among other flaws. Derailments cause significant damage to the exhibit, rolling stock, and motive power. Case in point; there are various wayside signals; specifically dwarf or pot signals, and bridge guards which already have substantial damage from an operator being negligent or carelessly not paying attention. Since then, many signals have been repaired. They are fragile and if mishandled, they will fracture and become inoperable.
Depending on the types of decoders you prefer, it is not whether a decoder manufacturer is superior from another. It is about how you take control by correctly programming the decoder to do what you want it to do. Some car owners prefer BMW over Audi. Identically we have members who enjoy products produced by ESU or Soundtraxx. I prefer products by Soundtraxx and Audi. When I started to delve into DCC to increase my knowledge, I wanted to be able to operate model trains with helpers without utilizing another operator to handle the helper set(s).
An annoyance I was confronted with was that one or two locomotives would hesitate specifically at low speed. One would assume a locomotive from the factory would be ready to go. However, that is not always the case.
The following CV or Configuration Variables mentioned are specific to Soundtraxx’s Ecconami, Tsunami, & Tsunami2 Decoders:
After I install a decoder or after purchasing a model with a factory installed decoder, I immediately work out all the mechanical bugs to ensure the engine runs with little or no audible gear or motor noise. After I accomplish the mechanical discrepancies, I adjust the VStart (CV2). VStart assigns the amount of voltage sent to the motor based on throttle settings. You do not want the model train engine to take off at max speed at speed step one, but rather very slow. By adjusting the VStart, at speed step one, you want to ensure the model doesn’t jerk and continuously run slowly without stopping.
The Low-Speed Compensation (CV211) may need adjusting which will improve small driveline and gear binding. This type of binding will give the appearance the locomotive may be hesitating or slightly jerking at slower speeds.
There may be circumstances where you need to go back and adjust the VStart to compensate for the adjustment(s) made to CV211.
In addition, BEMF Reference Voltage (CV215) might need to be fine-tuned. After I make these adjustments to alleviate any jerking or hesitation, I would adjust the speed to the desired matching rates. Before adjusting the speed, I need to set the Speed Table Enabled (CV25) to a value of 2 and Configuration Data (CV29) to 50. From there you can adjust the speeds based on direction; Forward Motor Trim (CV66) and Reverse Motor Trim (CV95). Once you set the speeds and all engines are precisely matched, you are good to go. You need to understand not all model train engines will have identical values when programming their respective controlled variables.
I am only acquainted with Soundtraxx sound decoders. Momentum settings MUST be precise regardless of decoder type. Otherwise, you will have operational problems. Your CV3 (Baseline Acceleration Rate) and CV4 (Baseline Deceleration Rate) settings must match the values in CV23 (Consist Acceleration Rate) and CV24 Consist Deceleration Rate).
CV3 = 30
CV23 = 30
CV4 = 15
CV24 = 15
CV23 and CV24 should be assigned on all your engines so that when you include an engine as a trailing or lead unit in a consist, the engines will accelerate and slow down in unison.
DCC is not difficult and can be challenging if you do not achieve the desired functions. Once you acquaint yourself with programming, you will have yourself a very prototypical operating model train. It is a matter of reading all the available materials from the decoder manufacturers.
There is more to installing a decoder, assigning it a road number, and running it around. You can achieve so much more when you utilize the decoders to their fullest potential. Remember, a decoder is as good as you want it to be provided you tell it what to do by programming it.
I do not use JMRI and prefer utilizing the hammer head NCE Controller when programming my locomotives and rolling stock with decoders. It forces me to adjust the controlled variables from memory, but I also suggest keeping notes in a mobile phone for reference.