Speed Matching Loco's for MU Consist

[Herc Driver]

I've read and re-read the Digitrax Zephyr book about building a consist. I can program the engines to run as a MU consist, but only those that are already closely speed matched stay coupled. Unfortunately, I haven't cracked the code on how to match each engine to each other within the consist. I understand you can use the basic 3 Step Speed Tables and the 28 Step Tables, but really don't understand "how" to do it. I've spent tonight reading various articles on the web concerning this topic and have learned some tips.

1. Match the loco's using a typical consist of cars in tow instead of running by themselves.
2. Match the loco's when they're not coupled together.
3. Try to match passenger loco's separately from freight loco's...unless you want to run mixed pax/freight.

Ok, maybe those are the "big picture" points, but what is still escaping me is the "how". I have a Zephyr system and going through the manuals, there's very little about how to actually reprogram the CV values to build a consist that is closely speed matched. (My only criticism of Digitrax is that they seem to write their manuals assuming the reader has a fair amount of DCC knowledge...IMHO.)

Am I missing the obvious? It there a pretty good tutorial out in cyberspace that explains how this is done? The way it seems now, you have to program (on the main) each CV value for the 3 or 28 Step mode while both engines are moving on the layout until they match in speed. Is it that simple? Why can't you just have an engine pull exactly the same train of cars over a set timed distance, and adjust the CV values until that engine pulls the same weight of cars over the same distance all at the same time? Wouldn't the engines be matched then, or at least closely enough that you wouldn't need to reprogram them again?

Ideally for our layout, which is supposed to be simple enough for a 12 and 10 yr old to run, I'd like the ability to take any two engines, couple them up and run them as a MU consist without having to reprogram them all the time. I know this is not very prototypical and negates what some engines were designed to do and operate (in real life), but for myself and my boys, being able to hook a few diesels together and run them with a long string of cars is all we wanted to do with DCC. And so far, that's the one thing we can't do.

Any info, help or ideas would sure be appreciated.

[woodone]

Herc,
Speed match the locos before you do a consist. Run them seperate at speed step 1 then 10 then 20 and work you way up to your top speed. Run them together but not connected untill you have them running the same speed at each speed step. Also some brands of decoders do not speed match well with other brands. If you can use the same decoder brand in each loco you plan on MU ing this will help too.

[Herc Driver]

My apologies for a decidedly small amount of DCC knowledge...but I've re-read the manual, and there's nothing that I can decipher telling me step-by-step how to adjust the speeds. Right now, it's like someone threw a calculus book at me and said, "solve this equation." There's paragraphs discussing the "speed tables" and various values for many CV's, but it's still greek to me. I'm at the point where I need to write Digitrax directly for pointers. There's a forum group devoted to Digitrax products that I'll try too. Hopefully, someone has walked down this road before and cracked the code, and can explain it to me step-by-step since I'm just not seeing how to solve this programming procedure.

Thank you for your idea though...I will give it a try. What do you mean by "speed step 1 then 10 then 20"? Are you talking CV values or throttle positions? Do you run a single engine over a fixed distance to get a speed (like a scale miles per hour)?

It makes the most sense to me to measure the distance between two points on the layout, run the engine at a set throttle position, time the engine between the two points and record the scale speed. Then do it all over again for several other throttle positions. Once you have that down for one engine, do it for another engine and adjust the CV values (which I don't know how to do or which ones to change) so that the engine covers the same distance in the same amount of time at the same. So if they're MU'd together, they'd run well with each other.

If I decide to have almost all my engines run at exactly the same speed, wouldn't they all be "matched" and capable to be MU'd without uncoupling due to speed differences?

[woodone]

Herc,
I will try to clear some of this up. When I speed match two locomotives I use CV 2 (start volts) CV5( maximum speed) and CV6( mid speed). Note- not all decoders have all of these CV's.
You can also use CV3 (start delay) and CV4 (brake delay) I would stay very low with the values in CV3 and CV4, like 2 or 3. If you get too much set in these two CV's (CV3) will make the locomotive very slow to respond to the throttle- same goes of CV4. CV3 is the accelaration rate and CV4 is the braking rate.
Then I put the two locomotives on a large oval of track and run them at speed step 1 and use CV2 untill both run about the same. Then try using speed step 5 and get them to run the same, You work you way up the speed steps untill you have reached the max speed.
Most of the time I get one locomotive to run like I want it to. By using the CV2-CV3-CV4-CV5 and CV6. Then I use that locomotive and try to match others to run very much like it. When you MU them they should run as a team and work together and not fight one another.
Like I said in a earler post, some brands of deoders do not match well with other brands.
Hope this might help.

[Herc Driver]

That does make sense and I appreciate the clarification. I've been reading the Digitrax book and it's a little short on explanation. I know it's not prototypical, but I had hoped to speed match all the loco's identically so the boys could grab any two and run them without problems. Thanks again!

Of course, any other great ideas or tips on how you speed match your loco roster...just write 'em down here...it sure illuminates the text in the manuals.

[woodone]

Herc,
I sould expand on the CV2 setting. This is starting volts so it will be good for only the first speed step. Try to set all your locos so they creep at speed step one.
CV6 is the mid speed- CV5 is the max speed. You have to watch CV6 as some decodrs will difer in what it does.
I feel for you on the reading of a Digitrax manual. :? To much like reading a coumpter teck book- and the read out on the throttle is not that clear.
I am a NCE user and find that the display is very easy to understand. Not a thing wrong with the Digitrax products- I am just a slight bit challenged in understanding what they are telling me. :oops:

[Herc Driver]

I hear ya about the manuals...that's why there's pictues in my pilot/aircraft books. I've read over those parts and hope to "test" out whatever knowledge I gained very soon. I would think that trying to match similar brand engines would be slightly easier than between different brands...but maybe not.

Either way, thanks for the advice...I plan on acting upon it very soon.