# Slow locomotives



## Vonspif (Dec 24, 2019)

I just purchased a NCE Powercab and a couple of Dcc locomotives. They run much slower on Dcc than dc. Is there any way to turn up the speed ? I have HO scale.


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## Tom_C (Jan 8, 2016)

There *may* be, there are some speed increment settings, but I don't play with them myself. Do you have all the programming information for the locos? You'll need that. Post what locos and/or decoders you have.


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## mopac (Feb 24, 2011)

As Tom C said, there may be a CV for top speed. In general, I have found DCC
does run a little slower than DC. Your track voltage on DCC is lower than what a DC transformer can put out.


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## MichaelE (Mar 7, 2018)

Locomotives running DCC will still run at a realistic scale speed. If you are used to trains running around a loop in the blink of an eye like toy train O scale, HO scale speed is something to get used to. It does not look fast to the eye.

If they are covering 36" of track in about 4.2 seconds they are traveling at a scale speed of around 41 MPH give or take.


But yes, there are many settings in the CV's to control many motor speed parameters. Be careful in there. They are easy to screw up if you don't understand what you are changing.


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## CTValleyRR (Jul 26, 2014)

A DC power pack at max puts out around 16 Volts; track power for most DCC systems is around 14V, so you'll never reach the same max speed with DCC. However, as MichaelE points out, max speed with DC is usually much faster than the full sized equivalents ever run. Most locos with factory-installed decoders come programmed to run at realistic speeds, and this may look surprisingly slow to you.

Look at the documentation that came with your decoders. There should be a list of Configuration Variables (CV's) and what they do. You're looking to set the one governing max speed (or max voltage) to it's highest setting. The specifics on how to do this vary for different DCC systems and decoders.

If all else fails, setting CV8 to a value of 8 will reset most decoders to their factory defaults, so you can get back to a known good condition if you really mess things up.


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## spikedrivingblues (Dec 11, 2018)

Not sure if this is what you mean or if it will help you but if you are running 128 speed steps, try 28.


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## D&J Railroad (Oct 4, 2013)

DCC isn't going to run your train at slot car speeds. 
One way to ensure you are getting top speed out of your decoder is to set CV 5 to 255. That is the top end speed command of the decoder, not the locomotive speed. CV 6 will let you adjust the mid range speed, about 125.


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## Vonspif (Dec 24, 2019)

After operating these for a period of time,I am becoming accustomed to the speed. I am not experienced enough yet to start changing advanced parameters. Thanks for everyone's help.


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## J.Albert1949 (Feb 3, 2018)

OP wrote:
_"I am not experienced enough yet to start changing advanced parameters."_

There's not much to this -- at least at a basic level. (at least on the Roco z21 system that I use)

One thing you should do is before you change a particular CV setting, to write down what the current one is. That way, makes it much easier to "go back".


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## Tom_C (Jan 8, 2016)

J.Albert is right, nothing to it.

If you don't have a isolated programming track, take all other locos off the track, then on the powercab press prog/esc, select to use programming track, not main track, then select CV. Enter the CV to change and it will show you the existing value, then you can enter the new value. If you mess something up, just program CV 8, to the value of 8 to reset to default. Lather rinse repeat.

BTW, you don't need to enter all 3 digits. for CV 8, just enter 8, not 008. It will work either way, it's just not necessary.


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## CTValleyRR (Jul 26, 2014)

J.Albert1949 said:


> OP wrote:
> _"I am not experienced enough yet to start changing advanced parameters."_
> 
> There's not much to this -- at least at a basic level. (at least on the Roco z21 system that I use)
> ...


This reply is spot on. Changing the speed settings on a decoder is DCC 101. When you set up a decoder for the first time (that is, program the loco number), MRC systems ask you to also enter numbers for start voltage, max voltage, and mid-range. You can bypass these inputs if you want to, but since they're included in the basic set-up process, it's pretty obvious that those CV's are essential basic knowledge.

OTOH, you may not THINK you're experienced enough for "advanced topics"... but if you don't push yourself beyond what you already know, how will you learn and grow?


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## D&J Railroad (Oct 4, 2013)

Actually, CV programming is slightly more advanced than turning the headlight on or off.


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## Tom_C (Jan 8, 2016)

One other thing, which I was just reminded of. When starting with a new loco it might be best to reset it to default before you start. That way you are sure any CV you want to see the original value is actually reset to default.

I was just programming a new loco I got, and the CV's weren't matching what the documentation showed. I reset it to default and then went to look up the document on line. After I verified I had the up-to-date document I went back, and after I reset it to default all the CVs matched the document. So, just reset it before you begin so you are on a level playing field.


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## mesenteria (Oct 29, 2015)

Tom's advice has long been given by member Randy Rinker on another forum. ANY TIME you get a 'new' locomotive into your hands, be it gently used on eBay or brand new from the importer, you should first do a CV8 =8 reset or whatever the process is to get to factory defaults. That renders what you have a known quantity.


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## mesenteria (Oct 29, 2015)

Vonspif said:


> I just purchased a NCE Powercab and a couple of Dcc locomotives. They run much slower on Dcc than dc. Is there any way to turn up the speed ? I have HO scale.


If they conform voluntarily to NMRA standards, there are set voltages that each DCC system should apply to its outputs...BASED ON the scale. Different scales have different needs due to mass and resistances, so their voltages vary commensurately.

But, there are decoders, and decoders also vary. What they are asked to do varies, depending on the needs and decoder selected. But, they do things, and that takes energy. So the decoder gets all the power first, and then divvies it up to components in the locomotive, including lighting, drive mechanism, and sound system. This leaves the outputs for the motor reduced some from what the decoder needs for its own sake, and then what the lights and amplifier and speaker each need to do their bits. DC voltage just has to run a light and a motor.

Adjusting your drive to get the most out of the voltage and amperage available to it has been ably covered by the other responders.


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## DavefromMD (Jul 25, 2013)

With the NCE Powercab you can program CVs on the Main.


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## Tom_C (Jan 8, 2016)

DavefromMD said:


> With the NCE Powercab you can program CVs on the Main.


Absolutely. Someone else suggested to make note of the original setting before changing it, and you need to do that on a programming track. Programming on the main won't read the existing value.


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## Vonspif (Dec 24, 2019)

*Slow locos*

I am using a NCE Powercab with Mantua locos. I don't know how to check decoder information, what a cv is or how to locate them. I appreciate all the feedback as I have only been into this for a couple of weeks.


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## Tom_C (Jan 8, 2016)

I posted this already, but to read the CV value you need to set it to programming track, not main. That's why you need to be sure you remove all other locos unless you have an isolated programming track.

Press prog/exc, toggle through the options to where you can select 'programming track', then select CV. You then enter the CV# and it will read the existing value. You can then change the value or just press enter to keep the existing value without changing it.


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## flyboy2610 (Jan 20, 2010)

You need to push "prog/esc" 4 times to get to programming track. Then push enter. You will see a menu of options displayed. Push 2 to get to the CV programming page. Once on that page you push the number of the CV you wish to change. The PowerCab will read the value currently stored in the decoder and display it. Be patient, it may take a litle bit to read it back. Write down the current value so you can reset if you desire. To change the maximum possible top speed, enter 5 as the number of the CV you wish to change. Once the PowerCab has read back the current value, push 255, then enter. Pushing the "prog/esc" key takes you out of programming mode and back into operations mode. There really is nothing to fear about the process. The PowerCab makes it so easy, even *I* can do it!


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## CTValleyRR (Jul 26, 2014)

Vonspif said:


> I am using a NCE Powercab with Mantua locos. I don't know how to check decoder information, what a cv is or how to locate them. I appreciate all the feedback as I have only been into this for a couple of weeks.


Well, you will have to forgive a certain level of assumption on our part that one would not invest in a DCC system without some basic knowledge of what it does and how you use it.

It's a little disconcerting, however, to see you post this, and then have the next two people ramble on about CV's and how to program them without bothering to ground you in the basics first.

So, to get REALLY basic here: the type of DCC system you have is important, because the specifics of HOW to do things are unique to each brand. I have an MRC Prodigy Wireless, so I can't tell you exactly what to do to use your NCE unit.

The manufacturer of the locomotive doesn't really matter; who made the "DCC decoder" (the little printed circuit board and logic unit that interprets commands from the DCC unit and makes the loco respond appropriately) most definitely is. Your locos should have come with information on what decoder is installed, and what specific functions it has.

If all else fails, the manufacturer and model of the decoder can be read from the decoder itself.

CV is short for Configuration Variable -- pretty much just what it sounds like: a numeric setting of certain memory locations in the decoders microcircuits that tell it how to do certain things. Some of them are standardized by the NMRA (that's National Model Railroad Assn); others are specific to the manufacturer. That's why it's important to know WHICH decoder is in your loco (also, incidentally, why I purchase "DCC-Ready" locos and install my own decoders).

Take, for example the CV that sets the min voltage. IOW, when you increase to speed step 1, how much voltage goes to the motor. You may have noticed that in DC, you often have to crank the throttle to 50% or more to get the loco to start moving. Since DC is variable voltage, usually from 0-16, let's assume for illustration that 8V is the minimum value for the loco to move. DCC, the CV remembers that, so when you move to speed step one, it applies 8V DC to the motor, so the loco just barely creeps forward. Similarly, another Czv governs the max voltage. If the loco runs at a scale 100 mph at 100% DC throttle (16V), but the real machine has a top speed of 65 mph, then it may set max voltage at something like 13V to make that happen.

Other CV's tell the loco how fast to start or stop, which direction is normally forward, control sounds (if equipped) and much more. In order to program a new value, it's usually easier if you know what the old value is, so most systems have a way to read the value in each CV, but of not, trial and error still works fine.

I realize that's a long response. Hopefully it helps shed some light on the subject of DCC for you.


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## 65446 (Sep 22, 2018)

DavefromMD said:


> With the NCE Powercab you can program CVs on the Main.


Correct. But if it, or any other engines are still addressed to factory default 3 and idling, they will all recieve the same programs you're programming the one, also still 3 but about to be changed. 
I'm sure you know that either each engine need be given new, and different addresses (usually # on engine cab) first. Or, one can take all but the present one off the tracks and will be OK, too. 
When I had my last layout I did that dance myself. IE, I never had or needed an isolated programming track...


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## MichaelE (Mar 7, 2018)

My new five track Deutsche Bahn staging yard is going to have a separate programming track. Removing locomotives to be able to read the CV's for programming starts to be a PITA when the locomotives start accumulating.

With the decoder cards that some of my locomotives have, not everything can be programmed on the main either.


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## Vonspif (Dec 24, 2019)

Flyboy 2610, Thanks, works fine.


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## flyboy2610 (Jan 20, 2010)

Vonspif said:


> Flyboy 2610, Thanks, works fine.


You're welcome! :thumbsup:

I know how to do that because I have an NCE PowerCab. A stub-ended track makes a great programming track! Make sure you use insulating rail joiners to isolate the siding though, or you can have some very interesting results! 
NCE makes an automatic switch that will activate as soon as you select "programming track" on your throttle.
https://www.ncedcc.com/online-store/Auto-Sw-automatic-program-track-for-Power-Cab-p38322162

It's bit pricey, but it works really well! You can use a DPDT switch, but then the siding is dead until you throw the switch. You cannot run the locomotive onto the siding, program it, and then drive it off the siding with a DPDT switch. You have to put the locomotive on the siding and take it off by hand.
With NCE's switch, you can run it onto the siding, select program track, program it, go back to the main page, and run the locomotive off the siding. Easy, peasy, mac & cheesey! :laugh:
Here's a link to a diagram as to how to wire it:
https://www.traintekllc.com/nce-auto-sw-switch-for-power-cab/#gallery-2

The two output wires from the back of the NCE panel plug are inserted into the switch at the top, marked DCC. Two wires go out from the switch to the main track, two wires go out to the program track. That's it! The main and program track are live at all times allowing you to run a locomotive onto the program track siding. You then select "programming track", which you already know how to do. As soon as you hit enter, the power to the main is cut. Now only the programming track is live. Program whatever you need to program, and as soon as you go back to the main operations page of the throttle, power is restored to the main, and you can drive your locomotive off the programming track. It really is that easy!


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## 65446 (Sep 22, 2018)

Admin please delete this...I made a blunder in a reply here/decided to skip it...


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