Speed Matching

[669CPB]

I am trying to speed match 2 Hornby Virgin Pendolinos both with the same decoders.  All settings are the same but one runs slightly faster than the other.  Using Railmaster and Elite.

Decoder is Bachmann ESU 36-553 .  CV settings for both are

2  Start voltage  003

3   Accel rate  000

4   Decel rate  000

5   High Speed Voltage   042

29  CFG data  006

49  EMF feedback   001

51  DC brake control  001

54  Feedback K   032

55  Feedback I   024

63  Function brightness   007

 

Is there a CV setting I can amend to sort this?

 

Many thanks

Chris

 

 

[Chrissaf]

You haven't said, but I assume you are running a long Pendolino train with two motor cars, one pulling and one pushing.

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Are you running them as a 'consist' or have you just given the two decoders the same DCC address. There will inevitably be slight manufacturing tolerance differences in the motors, even in two locos of the same model and vintage. If they are older models the motors may have aged (worn) differently. It is not unusual to find locos that do not perform the same in both directions. So a one pushing and one pulling configuration means that the rear loco is going backwards. If this is the case, can you not just put the faster loco at the front in pulling configuration.

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[669CPB]

Yes, running a long Pendolino train with motor at each end.  Locos have different DCC addresses and running them as a consist.

Reason for the two motor cars is that all was ok with one when pulling but pushing caused plenty of wheel slippage and the odd coach derailing.

I had a spare motor from a set purchased on ebay as non runner which I got for the coaches only really.  I found the non runner was due to one of bogies being the wrong way which was causing a short. 

 

[96RAF]

I don’t know the characteristics of the decoders you are using but you can get decoders which will learn a motor characteristics, and that may help match these two locos.

 

The way it works is you set the loco on a track long enough for it to run for a few seconds, then set a prescribed CV value which enables the learning function. The loco sets off on its own up to top speed and the decoder learns from the transit, before stopping the loco.

 

For the life of me I cannot recall which decoder make/model has this feature, nor can I remember the exact terminolgy for it to aid a search. Maybe this post will trigger someone to recall the information.

[Chrissaf]

Hornby tend to use dummy rear motor cars for a reason .... you have just found it.

[Rog RJ]

It may be stating the obvious but what you need to do is slow down the fastest loco to match the slowest, this is done by adjusting CV5 in the fastest loco to a lower value.  You may also need to adjust CV2  to get the two motors to start at the same speed step by adjusting CV2.  Ideally, the decoder would also have CV6 available to match the mid speeds.

 

I would give both locos the same address and put them both on the track at the same time but separated by some distance so that you can see the effect of the CV adjustments a lot easier than when they are coupled together.

[669CPB]

Thanks for the replies.   

I have a couple of new lais 4 function decoders that I will try to see if they help.  Think the post about slowing the fastest loco using cv5 will be more use though so will try this as well over the weekend

[669CPB]

adjusted cv3 & cv5 and the two are pretty well matched. One very slightly faster but only noticable after about 5 circuits.

Reduced cv5 to 40 on the faster loco and increased cv3 to 4 on the slower.  

Would adding a bit of weight to the faster loco help at all?