Consist Issues.... CV help please!

I have a issue with my Kato Sd40 giving me irritating performance. I thought maybe it was a lube or electronic issue so I tore it all down and cleaned everything and it ran perfect. I have two locos running in consist and they have been flawless for a year now. I was running them and all of a sudden they would slow down and then start up again. I know it sounds like normal electric contact issues....... But when I separate them and let them work alone they both run FLAWLESSLY!

I don't know what the issue is but let me post my CVs and maybe someone has some advice on what to adjust.

I run a Digitrax 51 Control Station

LOCO #1
Digitrax DN163AO
CV 29- 38
3&4- 15
2 - 5
6- 40
5 - 93
54 - 1
55 - 80
56 - 20
57 - 15

Loco #2
LENZ

CV 29 - 39
3&4 - 50
6 - 118
5- 150
2 - 45
54 - 10
57 - 30
9 - 20

Please...... Someone who understands BEMF and CVs can you tell me what is the possible problems?

 

I am not an expert, maybe one well post soon.

But, I have seen posts where similar problems where being caused by the DCC controller. It will probably help if you identify the controller you are using.

Bob

 

What kind of Lenz decoder do you have?
And which decoder was in the Kato SD40?

-Mike

 

Both locos are Kato SD40s and the Lenz is in a non DCC model that I bought used already installed. It's been professionally installed but I am not sure what decoder model it is for sure.

 

Need to know what type of Lenz decoder. Silver and gold support CV5 and CV6. Older model Lenz decoders do not. So a speed table is required on the older models.

 

I have never heard of a Digitrax 51 Control Station but then I am 75 and find that I easily forget stuff, so that is possible.
You say ;

Now to help understand and do not take this question the wrong way. Do you mean that your are just running them together with both decoders having the same address or do you actually have them consisted with different addresses on your Digitrax throttle? ?

Carl

 

Are you using Universal consisting (Digitrax's default, MU+/-) or are you doing advanced consisting (CV19 addressing)? If you are using universal, then one thing you might try is to reset the Zephyr. The Zephyrs I have used every once in a while get a little 'hinky', and a reset fixes them. Do a program-switch-39 change, see what happens.

A less likely possibility, and this should have appeared from the start if it were the case, is that if the two decoders both have beck-EMF active they might be bucking each other. If you turn back-EMF off in both, test run them and see if you get a change. You'll probably need to adjust the start voltages (CV2) of each to get them to speed match at slow speed if you try this.

Lyle

 

I am not sure what Lenz this is..... But maybe a picture will help.??

 

I have speed matched both locos best I can and run them off the same address in MU function

 

Thanks.... I am using the Universal consisting then... I just use MU +/-. I have heard about CV 19 but haven't tried that yet. Let me see what I can find about resetting the Zephyr and see if that is it. It does sound like the best suggestion so far and does make sense

 

I'm pretty sure that decoder is an older Lenz Gold mini. The three unused gold pads is a giveaway.

http://tonystrains.com/?s=lenz+gold...ts&utm_content=/technews/lenz-gold-review.htm

It sounds to me like a BEMF problem. As Lyle pointed out above, my first troubleshooting step would be to turn off BEMF. In the Lenz Gold, you do this by setting CV50 to 64 (a setting of zero in this CV turns BEMF back on). I don't use Digitrax decoders, so I can help on how to turn BEMF off/on on Digitrax. You may have to play some with CV's 2, 5 and 6 with BEMF off to get good speed matching, but the key here is to see if the weird behavior changes. If this step smooths things out, then turn BEMF back on on ONE of the engines, but not the other and see what happens.

John C.

 

Thanks very much John....... I will get back with you after I try these things

 

Well time for some updates of sorts. I spent some time last night and turned off BEMF on the Lenz and reset the Command Station and Digitrax decoder. I then started to check my speed matching and at full speed they were off quite a bit. I tried to fix it and had issues programming in OPS mode. I have done this before but I couldn't get them to talk last night ...... Any suggestions? I hate to do it all in DIR on the side track. That is a royal pain

 

Thanks again everyone for the help. I finally have everything running smoothly again and I am relieved. I turned off the BEMF on both locos and then re-speed matched them.. They were running close but not perfect so after relearning how to program on the main, I was able to get them really close. I have not tried BEMF yet but at the moment they run really really good and I am not having the shut down issues from before. I don't know exactly what the issue was but I now know that I should double check any other locos before I hook them together.

 

I may draw some flack for what follows, but decide for yourself. I usually disable back-EMF sensing on my own locomotives when I intend to consist them. A decoder senses the back-emf voltage from the motor it's connected to, as the load changes it responds to compensate. If an adjacent locomotive tugs or pushes a couple, the loading on the first motor changes and the voltage changes. Depending on how sensitive the decoder is to these changes, there can be exaggerated bucking and/or boosting. I believe that is what happened in this case, but I am confused why it was slow to develop. Some decoders have the ability to adjust back-EMF sensing, response, etc. While doing this does not require black magic, it can be tricky to do and will take time and patience. I find it easier to turn off the sensing. I also like the idea of being a bit more of an 'engineer', having to increase and decrease the throttle as the terrain and loads change. That's simply my take on this.

Lyle

 

Another thing that will cause the same type of problem is to have one of the locos selected on two throttles at the same time.
I have never seen a need to turn BEMF off, it works great for me. I like the governor effect, just like the real thing.

 

One other thing to think about is setting up the Lenz decodered locomotive exactly how you want it to run using a speed table.

Now add that same speed table to the Digitrax decoder. Now you have the ability to fine tune the Digitrax decoder using Trim settings. They allow scaling of the speed table either faster or slower without changing speed table curve.

You can do this using CV66 for forward motion and CV94 for reverse running to match the speed in both directions.

Last but not least, you can use CV65 on the Digitrax decoder (Kick Start) in the event it is slower starting than the Lenz decoder. I do not use Lenz decoders, so I am not sure if they have Kick Start.

Using decoder with trim capability can be made to match almost any non-trim decoder, the thing is the non-trim decoder now is the standard to be matched.

This method of speed matching can make different manufacturers to run with each other, such as Atlas SD60M's running with Kato SD70MACs easily.

 

Sharkman,

Thanks for the help but I must be honest...... I understand the concepts here but I have never been successful in execution of them. I have given up on using speed tables because I don't understand how to use them correctly. I have only been successful with CV 2, 6 and 5 for speed matching. I have tried....... But got so confused and lost that I went back to simple. If this doesn't work soon I may just ditch the Lenz and switch to a ESU Loksound decoder or just try to use all the same decoder but I have not settled on what I like best.