Speed Matching Engines w/DCC

[Anonymous]

[?]I have a few engines I want to run as MU. When setting them up run as a consist, I notice that the lead is pulling the second engine. I have a Digitrax Super Empire Builder set with Digitrax decorders. I've read the manuals, and I can't quite figure out how to speed match these locos so they pull as one and not one pulling the other.

I need both engines working together so the train make it up the grade!

I tend to get lost in the instructions when Digitrax starts talking about CV02, CV03, loadable speed tables, curves, etc...

Is there an easy way to accompli***his?

[jfugate]

You bet. With digitrax decoders, its really easy (that's what I use).

First, set CV19 on both decoders to the same two digit number, I like to use the last two digits on the cab of what will be the lead unit. This will consist the two units together.

Make sure the two locos have the same speed steps (I like to use 128) and similar start, mid, and top voltage settings. If the locos are made by the same manufacturers, the ideal is to have the same brand of decoder in them with identical CV settings for speed.

Now put the two locos on parallel track side by side and run them through the their speeds from start to top speed. CV66 is forward trim and CV95 is reverse trim. A value of 128 in both will make the loco run at 100%.

Take the faster of the two locos going forward and set its CV66 to less than 128 to slow it down. Try various values until the two locos run side by side most of the time through all speed settings going forward. Some slight variation is okay, as long as they both start up about the same and reach about the same top speed you're good.

Then run them in reverse and set CV95 of the faster loco to something below 128 to slow it down. Again, once you get them both to run side by side at about the same speed then you are good to go.

And that's it. Works like a charm!

Joe Fugate
http://siskiyou.railfan.net

P.S. I am doing a clinic at the Seattle National in July about DCC hints and tips and will be demonstrating this and other DCC tips as one who has used DCC on my large Siskiyou Line layout since 1993.

In case you miss the clinic, I will also be putting this and other tips in my video on DCC hints and tips, due to be released this fall. See http://model-trains-video.com

[jfugate]

One other tip for programming CV19 - if you add 128 to the number you program in the CV, the loco will run backwards. So if you have two locos, 4422 and 4408 and you want to consist them together, but have 4408 run backwards, then program 4422's cv19 with 22 and 4408's cv19 with 150 (22 + 128).

By doing this, 4408 will run backwards when you address loco 22, and 4422 will run forward.

[AntonioFP45]

Jfugate,

Great info. When the video is released, don't forget to post it here and remind us. It's good to know that you're operating with Digitrax DCC.

Are you using the "Super Chief"? Also, are you using sound decoders from Soundtraxx?

Thanks! [:)][8D][tup]

[jfugate]

Antonio:

I'm using Digitrax decoders with an EasyDCC system. I like EasyDCC's wireless system a lot, the throttles are simple and straightforward for my operators.

I also use Soundtraxx decoders for sound in some of my loco lashups. I use the 75LC series because they are cheaper and I think they sound fine for EMD diesels.

I program my lashups so F0 is the main headlight, F1 is special headlights (gyralight, mars light, ditch lights, etc), F2 is horn, F3 is bell, and F4 is dynamic brakes. Since the basic EasyDCC wireless throttles have F0 - F4, this works peachy keen.

I also program my diesel lashups so they are double-ended. This means if I have 4422, 4333, and 4408, my operators can dial up consist 22 and run the lashup with 4422 as the front and the function keys run the lights and sound.

They can at the end of a run (such as with a turn that switches eastbound to a specific town turns, and then switches westbound back to its destination) dial up 08 and then 4408 becomes the front of the lashup and the function keys operate everything on that end of the lashup.

It's a bit tricky to describe how to do that without pictures or lots of steps, but once you've done a few of them it works great and it makes my operators' lives very easy during an op session on the Siskiyou Line. I'll be covering how to do this in the clinic and video as well.

[Anonymous]

Thank you Joe. Just the simplified answer I was looking for. Now I know how I'm going to spend my cold and rainy Saturday morning!

The two locos I have are both Atlas GP-38s. One has an Atlas dual mode decorder and the other has a Digitrax decorder. I hope this doesn't effect the the set-up too much.

Thanks again.

[dano99a]

You can also commpli***his ( but it takes more time) by programming CV2 (start voltage) CV6 (mid Voltage) and CV5 (max voltage) usually I have adjusted the mid voltage to get them close. Now, I've never tried using the forward(CV66) and reverse(CV95) trim but I can understand why it would help greatly (they act like a volume knob to each)

Even if they are from the same manufacturer your still going to have to do "some" adjusting. I use all proto engines and they all have come from different production dates so they have slightly different power usage. but it sure makes it easier than adjusting an atlas to a proto (yikes!)

Thanks "jfugate" for the tip, it's funny because I was just in the process of doing this (speed matching for consists) when I came accross this posting.

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UPDATE 5 minutes or so later:

ok, jfugate, maybe I'm losing it but, the forward and reverse trim do not effect anything unless your using a speed table. I'm using CV's 2 5&6 to adjust my speeds for matching and the trims don't seem to effect them at all. [:(]

I followed your instruction exactly as you posted them except I'm not using a 128 speed table and the results from adjusting the trim didn't do anything. Suggestions?
I'd really like to try this...

But, Here's what I'm doing:

Most of my locos use a DH163LO (digitrax decoder for GP7's & 9's) some use the DH123

I have two locos on the same track in a consist, spaced about 4 inches apart. I set the CV's 2, 5&6 with the same values on both locos.
example:
CV2 (starting voltage) : 30
CV5 (max voltage) :218
CV6 (mid voltage) :100

Cranck em'up to mid point (speed).

I take the slower loco and increase CV6 (mid voltage) until they remain the same distance apart going forward and backward. The only reason I don't run em' up to top speed is that real GP7's never moved that fast. (IOW: I try to run my engines at proto speeds). After setting that I then speed match all my locos to the faster (using the consist method) loco so that I can consist any of them together and not have to do it again.

Now the only problem I've had, since I have an Empire builder, is that it won't let you read what a CV is currently set to. So, I have an excel spread sheet here on the laptop that I punch in what I set so I know what all the engines are set to.

Thoughts? [:)]