DCC CV settings with Farish steam locos.

[Andy_C]

What it says, really. I have several steam locos, and am enquiring if there are any recommended CV settings for them - in particular the acceleration and deceleration cv’s. 
 

Im using the Rails (DCC Concepts) 6 pin, and Gaugemaster 6 pin decoders. I have a couple of Zimo ones, too.
 

I have 2 Class 4 MT’s, 2 Class 3MT’s, 2 Class 5MT’s and a Black 5, amongst others. 
 

Do I just have a gentle tinker with them to get to the combo of settings I like, or has anyone else done this?

 

I’m sure I’ve missed some detail out, so ask away?

 

Thanks in anticipation of any suggestions/help.

 

Andy.

[WIMorrison]

May I suggest that you describe what problem you are having with the locos present performance before you start changing anything? You also need to be aware that the CV setting fos one loco and decoder are highly unlikely to work in the same model of loco with a different decoder. In reality even with the same decoder in an identical locos the CV setting will probably be different to get the same, or similar, performance. 

[Andy_C]

3 minutes ago, WIMorrison said:

May I suggest that you describe what problem you are having with the locos present performance before you start changing anything? You also need to be aware that the CV setting fos one loco and decoder are highly unlikely to work in the same model of loco with a different decoder. In reality even with the same decoder in an identical locos the CV setting will probably be different to get the same, or similar, performance. 

I’ll do that. I’ll do a running session at the weekend with a couple of them, and post on here. I was thinking exactly what you’ve said, re each loco probably ending up with unique settings to get them the same…

 

[AMJ]

Might be an idea to calculate the max speed you would like to run them at and adjust the Vmax.  Many decoders use a trio of CV's for min, mid and max speeds.  Check online for a manual but might be CV's 2, 6 and 5

[Andy_C]

2 hours ago, AMJ said:

Might be an idea to calculate the max speed you would like to run them at and adjust the Vmax.  Many decoders use a trio of CV's for min, mid and max speeds.  Check online for a manual but might be CV's 2, 6 and 5

Thanks - I've been reading up further, and to factory reset a decoder looks simple enough. I have a programming track on my DR5000, so a littl experimenting might be in order.

[jamesed]

Sorry, I'm a bit late to the party but maybe this will help:

 

First of all start with the Zimo decoders.  These will be the easiest to get running well and that will give you a benchmark to try and replicate with the others.

 

1)  first of all, if you aren't using Railcom and you don't want to run your locos on dc then set cv29 to 2 or if you are using long loco addresses (3 or 4 digits) to 34.

 

2) As AMJ said, now is a good time to set the maximum speed for the loco which, with a Zimo decoder, is best done with cv57. The value range is 0-255 but start with something like a value of 80, try that and adjust up or down until you get the max speed you want.  To calibrate to a scale speed there is a good caclulator at https://www.modelbuildings.org/scale-speed-calculator/

 

3) The default for your start up voltage at cv2 will be 1 which you'll probably find ok but you can increase this if you need to. If you set a very slow acceleration rate (cv3 see below) then you may find it better to set cv2 to a slightly higher value.

 

4) The acceleration rate on cv3 has a default of 2 but you'll probably find it better to set this a bit higher. I'd suggest starting with a value of 8 and adjust up or down to suit how you like it.

 

5) The deceleration rate on cv4 has a default of 1. Personally I like to have good control of stopping exactly when I want so usually I set cv4 at a value of 2 or sometimes up to 4 but it's a personal preference. Zimo chips also usually give you the option of setting up active breaking which opens up a lot of additional possibilities and is especially good for sound. Read the manual if you want to learn more about that. 

 

6) If you've set up the max speed using cv57 then you can leave cv5 alone.  When you come to the other chips you may need to use cv5 to set the maximum speed but remember that as you reduce the value of cv5 you are also reducing the number of speed steps in the curve.

 

7) The mid point speed on cv6 is probably the most helpful setting. On a Zimo you may find you don't need to adjust it. The default value is 1 which is a shortcut value to make it a third of the maximum speed value, in other words on a scale of up to 255 it will be a value of approx 85.   If you find you want to adjust it then try a litlle higher at, say, 100, or perhaps lower at 70 until you find a value that suits how you want it to operate. With other decoders you will probably find you need to play around with cv6 a bit more and that will also then be dependent upon what you have set cv5 to. 

 

Get your Zimo decoder locos working how you want them first before you start on the others. When you do move on you'll find out why so many of us prefer Zimos (when we can get them!) but by then you'll have a better idea of what you are doing which will help.

 

 

 

[Andy_C]

@jamesedthat is a very comprehensive reply. Thank you for taking the time to do so. I'll read up again when I get to Sunday and am with the railway again. I do have a mixture of decoders but do suspect that with time I'll obviously identify a favourite for various reasons.

 

Thanks again,

 

Andy.

[peterm1]

Just to add to Jamesed helpful reply. You can have braking on an F key. If you set CV309 to 2 (my preference, but you can use any key you want) you'll be able to operate the brakes. Then CV 349 gives the braking effect, I set this to 5 normally.

 

If you're using a stay with plenty of storage, it's a good idea to limit the amount of run time on dead track. I set mine to 2 seconds for safety. This is set with CV153 set to 20 (tenths of a second. Then set CV111 to 1 so that when CV153 comes to the 2 second limit, the loco will stop dead instead of going to the CV4 deceleration setting.

 

Hope this helps.