# matching speeds to consist



## I Am Fasha (Apr 2, 2013)

Need help, again...

Below is a picture of two Backmann locos Im trying to use speed tables to match them so I can consist them to run together all the time. As you can see, they have to me, what appears to be the same decoder, just made at different years. When I read them on JMRI both were recongised as "four function decoder (36-550) One has a manufacture date of 06-11-11 and the other is 04-06-04. I would think this would be a easy task.

I have worked on these two for for over two hours, making adjustments in speed steps, try to get them to run close together, its not working.

Any suggestion would be greatly appreciated.


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## Southern (Nov 17, 2008)

Bring them over this weekend.


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## I Am Fasha (Apr 2, 2013)

SOUTHERN!!!!!

I cant!!! You still have that restraining order in Place!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :smilie_daumenneg:

Just kidding :smilie_daumenpos:

I will not be able to get by sir hwell: Too much going on. I will tell you what I did though. I kept adjusting the speed table of the fast one trying to get it to slow down to the slower one, by lowering the first step in the speed steps, matching ends, writing changes and saving. This just wouldn't work, it would not slow down to match the speed of the other. Then I started to raise the speed steps on the slower one, (same way as above) trying to get it to speed up, it would, but..... I guess I was "hoping" that since the were the same manufacture, with the same decoder, I could get them close, like I did with the Atlas Master series..

If Im still having problem next weekend, and you have time, I will come by. But!! I hope to have these two locos back to the owner by then :smilie_daumenpos:

BTW. I got them to where they were running at same speed and acceleration with one throttle at #7 and the other at #5, acceleration and stopping as a pair and then pulling off together, should this be the best that I can expect?? Should I be happy with that, install metal Kadee couplers and send it home?? :dunno:


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## DonR (Oct 18, 2012)

Fasha

Just for my own curiosity, were the locos identical models and did
they run at different speeds before you attempted to adjust them?

The reason I ask, I have 3 sets of paired Bachmann DCC locos: 2 FA. 2 GP.
and 2 GE 70 ton switchers. I run those as 2 loco consists. I bought
the locos at widely separate times. But I don't detect any substantial
variation in speed using my Bachmann EZ DCC controller which has no ability
to set the CVs.

Don


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## I Am Fasha (Apr 2, 2013)

Thanks for the reply Don! To answer your question, yes. GP40s. They did run completely different. One was a speedster off the line and the other seemed like it was running in slow motion off the line.

I opened up all tabs in JMRI and set everything I could to the same numbers: acceleration, stopping (sorry can't remember JMRI's name for that) everything that I could to make them equal.

I'm think that I may, may do a decoder reset on them back to factory. They were owned by two different people. Maybe one of the previous owners played with a CV. 

But! I see your point about being different models. If they were, the factory decoder could be set different for factory performance based on model.


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## spoil9 (Dec 24, 2008)

Ive never messed with DCC but from what I read, dont you want to set both locos to the same controler ID if you are going to run them together as a consist? That might test/tuning easier?


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## I Am Fasha (Apr 2, 2013)

Spoil you are correct and there are several ways to do, like you, Im reading a lot as well, and learning as I go. My experience so far has been trying to match two locos that were made by Atlas with factory installed decoders. Under the supervision of SOUTHERN, (our resident DCC Guru here) I learned about speed steps. These two Atlas were not the same models, one was an SD35 and the other a Dash 8-40c. We were able to get the steps and momentum adjusted to where they would start, stop and run together without cause as much stress on the couplers, as they were doing before.

But back to what you mentioned, once I get them running somewhat close together, I can MU them one of three ways if I have read the book correctly. One is to consist them with the cab or throttle. The other is to use JRMI and assign them the same decoder address. This is the way most people assign numbers to larger locomotives like the DD40 which has two motors. Most people when installing a decoder in this loco will install two, since it has two motors and then assign both decoders the same address as I mentioned above. Now if I have read correctly, the third way to do this consist/MU thing, is too assign a two digit number for the two locos having them consisted and leave the 4 digit address to run them as individual locos. I have not tried this yet.

But just by consisting them, it does nothing for the tuning of them, I think. LOL


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## DonR (Oct 18, 2012)

Fasha

I was wondering. Have you measured the voltage to the motor
of the slow loco and the speedier one with the controller set
the same and the decoders set to default CV? 
It should be the same in each loco.

Point is. If the motor voltage out of the decoder is
the same in both locos maybe the problem is not your CV settings, but a 
binding in the motor, trucks or drive system that is causing the
speed difference.

Spoil

If you are going to have continuous running trains setting the
decoders to different addresses in a 2 loco consist for 
speed matching would work fine.

I seldom run trains continuous. I have a single track main.
Trains running in opposite directions on it. That requires
a lot of 'diving' into passing sidings and stops. Sure would
be a lot of controller fumbling to have to slow, stop and go 4 locos each
with different addresses.

In the case of my GE 70 tonners I use
them for switching duties. Imagine the chaos of operating
2 controllers for one consist as you crawl in and out of spurs
to build a train on a lead track.

Don


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## I Am Fasha (Apr 2, 2013)

I have not Don and I see your point. Problems inside the drive line could be a problem. I will check that. I will look into the voltage, but honestly, I have a meter, but not that familiar with how to use it to test this voltage.


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## DonR (Oct 18, 2012)

Fasha

The decoder motor output is just plain DC.

Set your multimeter for DC voltage with the voltage
selection somewhere around 20 or so depending
on what your device has to choose from.

Your probes would go across the two decoder lead connections
to the motor. If you get a - (negative) reading, reverse
your probes on the connections.

Note: Be sure your controller is set for both locos to
go forward so DC polarity would be the same. Set
the speed control for what would be a fairly high
train speed if on the track. Try it also with a
setting for a slower train speed.

Don


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