Equalizing speed on two MM 071 locos

[controller]

Hi, I have fitted a MM 071 loco (088) with a sound decoder and all is working fine. I bought another 071, (086) and fitted this one with the decoder I took from 088, Non sound. This too is working fine. I would like to run these as a double header. Problem is, 088 takes off very fast, while 086 takes time to build up any speed. I remember reading, on this site , how to equalize both decoders, but cannot recall how this is done. Can any one of you gents refresh my memory, please. One more question please. I have 088 for a number of years now, and I think it may need a drop of lube oil. Can you tell my what parts need to be oiled, if any at all?. PS. I use a Gaugemaster Prodigy Advance.

Thanks,

Controller. 

[Dave]

The 2 locos need to be speed matched. The first step is to get the CV values for acceleration, start voltage and top speed matched. Then you run them one at a time and time them over a set distance, you fine tune the CVs to get them travelling over the same distance in the same time. This means they both run at exactly the same speed.

For double heading speed matching is important, it means one loco won't be pulling the other and therefore both pull equally across the acceleration curve. 

After I speed match 2 locos I set up the consist and then keep the 2 locos about 50mm apart, I run them and see if the gap opens up or closes. If the gap stays the same they are speed matched.

There are quite a few videos on YouTube on how to do it.

Hope that helps!

[controller]

Thanks Dave, I will start with YouTube and get as much information as I can, before I undertake the job. I know a small bit about CV values, but not enough, to dive straight into the job. I will let you know how I get on.

Thanks Again,

Controller.

[Dave]

11 hours ago, controller said:

Thanks Dave, I will start with YouTube and get as much information as I can, before I undertake the job. I know a small bit about CV values, but not enough, to dive straight into the job. I will let you know how I get on.

Thanks Again,

Controller.

No problem, just take your time and you can always reset the decoder if you run into problems. Start with one loco, play around with the settings and watch the effect it has.

[irishthump]

One thing you have to be careful of is differences in decoder brands. Some decoders (ESU Loksound in particular) use different parameters to control acceleration and deceleration. Also many sound decoders have a slight delay that makes the loco wait for the engine sound to rev up before allowing the loco to move off, this can make speed matching tricky.

Do you know what decoders are in each loco?

Edited August 9, 2019 by irishthump

[controller]

Thanks IT, The sound chip is MM 0055 DCC Sound chip for CL071/111. The non sound chip is one I bought for 088 in Marks Models a number of years ago. Now that I have had time to think about it , these locos never ran as double headers. So I think I will leave them as they are. Best not to mess around with them. They are running just fine.

Thanks Again,

Controller.

[Noel]

First thing is see if the two locos are running smoothly and freely and if necessary lube them. You can check this by running them a few feet apart on DC without decoders. If you cannot mechanically speed match them then its extremely difficult to do it with decoder CV values later. The second thing is to use the same decoders or very similar in both locos. In your case a LokSound in 111 and what sounds like a LokPilot in 088. These two decoders have similar motor CVs and both can be auto calibrated using the LokSound/LokPilot calibration procedure. After that you can experiment with CV3, 4, and 6 values (ie assuming speed curves are not set up). Some DCC controllers have  a specific speed matching procedure for consists (ie when locos and decoders are different). This allows you to match the speed curve of the secondary loco to that of the primary in a consist pair. But as Dave explained above its fairly easy to experiment with CV3,4, & 6 by setting the two locos a few feet apart and running them adjusting the CVs in one loco only until the gap remains consistent through different speeds and acceleration/decelaration modes. Have fun it may be time consuming but at least you have two identical locos to start out with (ie assuming both lubed and running freely)

[controller]

Thanks Noel,  The Gaugemaster Prodigy Advance is the control I use, and has a button ( DBL Head ) for double heading. I know this will set up double header running for two or more locos. I am not sure if it will equalize the speed on both locos or if I will have to play around with CV3, 4, 6. Can you explain what you mean by LokSound/LokPilot calibration procedure, I don't think I have come across that one yet. Thanks for the ton of information above. The user manual has a lot of instructions on how to set up double heading. I will sit down tomorrow and use all that information to try and get it right. Thanks again.

 

Controller.

[irishthump]

To use the auto tune feature: place the loco on a long straight section of track, 5 or 6 feet long if you have it. Then using your controller set CV54 to 0 then press F1. The loco will tear off at top speed and gradually slow to a stop. This calibrates the decoder to the motor and it should run better after this. Bear in mind you may have to do it several times for the best results and make sure the loco has been running for a good while before doing it. 

 

[controller]

Thanks IT,  I will try that.

Controller.