Hornby railroad diesel jerky slow running under dcc

[kenofchaos]

Jerky slow speed running from my Hornby railroad tts class 40 under dcc. However its like this with all my railroad models. I have a class 55 fitted with an esu sound chip and that runs the same. So it can't be the decoders (can it?) Has anyone else had this and managed to sort it out. Im running an nce powercab and the loco was running as speed step 10 of 126. The video link below should show you what i mean.

 

https://youtu.be/vnZiJYaMFjg

Edited May 12, 2017 by kenofchaos

[10000]

Have you run them in? It may help if you haven't.

 

I've seen similar behaviour from some Bachmann which was cured by turning off BEMF.

 

Your other solution is having the time and patience to tune the decoder settings.

 

​I have had similar behaviour from  Soundtraxx tsunami sound decoders, which are notorious for their poor starting, but there are CV's on them which when adjusted makes an amazing difference.

Edited May 12, 2017 by 10000

[Mike Buckner]

Step 1: Remove the body and see if t still runs as jerkily. I have a Hornby class 40, which, when delivered, had the wheels scraping the underside of the body, and the bogies scraping the underside of the body at the ends when cornering.

[shibushe]

Is the decoder a new one? If so reset it to default 3. Test it on 3.

Have had this problem. Reset cured it.

In fact reset it anyway.

[Dr diesel]

Hi Ken

Assuming the class 40 has a tts sound decoder in situ,

Reading the instructions in column 6, part 5 cv table 1,

You will see that CV151 and CV152 have a default value of 8

These control the motor parameters.

CV153 and CV154 also are an alternative set of motor control parameters with different default values

(See column 9 with the heading MOTOR CONTROL ALGORITHMS DESCRIPTION)

So programming on the main (Pom) set cv 150 to a value of 0 this will insure we are controlling the motor with cv's 151/152

Then change cv151 and cv152 to a value of 35 and see if that makes things better

 

Regards

Jeff

[Dr diesel]

Hi Ken

 

But the way your volume seems a bit loud.

Alter CV161 to a value of 1, it will sound a lot better.

 

Regards

Jeff

[JSpencer]

Hi Ken

Assuming the class 40 has a tts sound decoder in situ,

Reading the instructions in column 6, part 5 cv table 1,

You will see that CV151 and CV152 have a default value of 8

These control the motor parameters.

CV153 and CV154 also are an alternative set of motor control parameters with different default values

(See column 9 with the heading MOTOR CONTROL ALGORITHMS DESCRIPTION)

So programming on the main (Pom) set cv 150 to a value of 0 this will insure we are controlling the motor with cv's 151/152

Then change cv151 and cv152 to a value of 35 and see if that makes things better

Regards

Jeff

Very useful post, just tried it on my TTS class 31 chip in a detailed loco and it fixed the slow speed stutter.

[Chrisr40]

Hi , found this on the Hornby forum , apparently Hornby are recommending this to fix jerky running after fitting TTS chips.

 

 

he contacted Hornby and they told him to change CV 151 to value 255 and CV 152 to value 1

 

either of these two methods will make the locomotive run properly with the TTS decoder fitted. it basically changes the motor control algorithm. it doesn't seem to matter which of the two methods mentioned above you use they both give the same result there is no difference in performance that I have found.

[Trains4U]

For your ESU fitted loco, put it on a clear length of track (at least 4 ft)

Turn the sound off

Set cv 54 to 0

Turn the sound on.

 

The loco will shoot off like a scalded cat and stop.

This auto-tunes the decoder to the motor in the model.

 

Hope this helps

[ellss]

On 12/05/2017 at 21:44, Dr diesel said:

Hi Ken

Assuming the class 40 has a tts sound decoder in situ,

Reading the instructions in column 6, part 5 cv table 1,

You will see that CV151 and CV152 have a default value of 8

These control the motor parameters.

CV153 and CV154 also are an alternative set of motor control parameters with different default values

(See column 9 with the heading MOTOR CONTROL ALGORITHMS DESCRIPTION)

So programming on the main (Pom) set cv 150 to a value of 0 this will insure we are controlling the motor with cv's 151/152

Then change cv151 and cv152 to a value of 35 and see if that makes things better

 

Regards

Jeff

 

Very helpful, sorted out my Hornby TTS decoder issues in my Bachmann 37.

Thanks!