Controlling speed of Locos

[station master]

Hi All

Can you help me with setting my speed control on my locos, I seem to be having difficulty with setting it them to run at slower speeds or they run very fast, also when i reduce the speed to zero they run on for a good while, which settings do I need to be changing please?

[Steve M]

I know you are DCC so you will need to look at adjusting cv’s. Below is the NMRA list for info.

https://www.nmra.org/sites/default/file ... 012.07.pdf

But before you do anything at all, try setting the controller to 128 steps as this may give you the fine control you are looking for. After that, go for CV 3&4 which govern acceleration and deceleration.
Maybe start by resetting the decoder to factory defaults to see if that helps. Refer to the decoder manual as that may give you some indication on preferred values.

Be aware also that locos have different gearing that will affect the controllability.

[Paul-H]

Hi

In addition to what was said above

CV2 sets the start voltage, set it so the loco just starts to creep on speed setting 1

CV 3 & 4 set the acceleration and braking delay, set them to 0 for instant stop start, a setting of 5 to 10 would give a more realistic delay to start and stop

CV5 sets the top speed, useful to give a more realistic top speed I set mine to a maximum of 128 but often lower.

CV6 sets the mid point speed and is used in conjunction with CV5, so for example if CV5 was 128 set CV6 around 64 but they can be adjusted to your own tastes

Also as you change a setting write it down, otherwise you will loose track of what is set to what

Paul

[station master]

Thank you very helpful, speed steps i think is set at 128 as using NCE powercab and the highest it goes for speed is 128 is that correct?

[Mountain Goat]

As far as I understand, the speed steps are segments of the speed range. My DCC controller can do 14, 27, 28 and 128. Top speed and zero speeds should be the same regardless of how many speed steps are used (Assuming one has not set a starting voltage and limiting the top speed on the DCC decoder).
If your controller is set to have 128 speed steps, then yes. 128 will be the top speed.

[Brian]

If you're saying that at any speed setting at its maximum (whether 14, 28 or 128 steps are used) your loco runs too fast then you need to reduce the value of CV5. Read CV5 to see what its currently set to. Then reduce the read value by around 15% to 20% and retest. If its then too slow at max speed increase CV5 value. If still too fast at max setting reduce CV5 value more.
If your loco takes a time to come to a stop, even though the speed knob is at zero, then you need to reduce Deceleration rate by reducing the value set in CV4 to either 1 or 0.
If your loco takes too long to move off from rest when the speed knob is turned up the decoders Acceleration rate is set high. Reduce CV3 to a value of 1 or 0.

[ajcooper4]

I am having similar issues. Particularly I would like to be able to have more speed steps for finer control. I’m using a Gaugemaster Prodigy Express DCC01. I like the controller and only have three locos so fine for me. I’ve managed to reset loco addresses but I’m not confident at all about how to change other settings. Any pointers please?

[Steve M]

The Prodigy has a button to select 28 or 128 steps, so try that first.
You might need to change CV29 to allow 128 steps - use this calculator to establish the value. You will see that this CV also controls a few other factors - tick each box needed to get an overall value.

http://www.2mm.org.uk/articles/cv29%20calculator.htm

For example. 128 steps = 2 DC off = o long address = 32 total 34

On the programming track follow the usual process for setting the loco address, start and max voltage and acceleration and deceleration then the screen should say ‘CV’ enter 29 then the value from the calculator and away you go.

[ajcooper4]

Steve, thank you, but...I’m at the beginner stage with this. How do I know which CV is which & how do I change it. The manual tells me almost nothing!

[Steve M]

Steve, thank you, but...I’m at the beginner stage with this. How do I know which CV is which & how do I change it. The manual tells me almost nothing!

At this stage don’t worry about lots of changes as it is too easy to get confused.
Unfortunately the values needed can be different from one make of decoder to the next but each one should come with a leaflet that lists the CVs, their purpose, their range and the default settings.
I think I posted a link to the NMRA standard CV list at the start of this thread.

This is what I do for Hornby and Hatton’s decoders on my Prodigy following the prompts on the screen.
Enter Prog Track
Enter the new address
It will then ask for values for ACC, DEC, TV and SV (sorry but I can’t remember the order they come in) but the values I start with are
ACC 3 (acceleration)
DEC 3 ((deceleration)
SV 1 (start voltage)
TV 12 (top speed)
That should be enough to start (these values work for me but there will be plenty of alternative opinions) but if you want to be able to try 128 steps go one stage further
Then you get the message CV
Here enter the CV you want to change, in this case it’s 29
Next enter the value from the calculator and see how the loco performs back on the main track.

I have found that gives me a nice slow crawl on my locos although the physical gearing between motor and wheels will also have an effect.