Runaway DCC Hornby Castle

[Grahame Ainge]

I have a Hornby factory fitted DCC Kidwelly Castle R2897XS and although it works well most of the time, sometimes when the controller knob is turned (F1activated) the loco shoots off down the track (Bachmann E-Z Command Control). Any ideas please how to solve the problem since it can do a lot of damage when it unexpectantly happens?  As you may guess I'm pretty new to DCC. Many thanks, Grahame

[smokebox]

It can often be cured by turning off dc running capability in CV29.  I don't know if your controller can do that.

[rogerdee]

You can't change CV on the controller you have and the basic bachman controller is not that good should you decide to expand. If you know someone with a better system ask them to change the CV for you. If you intend to carry on with this hobby the best thing to do before anything else is get a better controller.

[Pete the Elaner]

+1 for turning off DC. Some decoders are fine, but I have seen others cause locos to shoot off at full speed after track power is suddenly restored after a short or while reading from the program track.

Beware about reading the CV bit though. I came across 1 decoder which reacted to the bit in the wrong direction: When I read it as DC enabled, it would not work on DC. When I turned it off, it ran.

 

As mentioned, if your system cannot change these, you will either need to upgrade or get somebody else to do it.

Edited November 17, 2021 by Pete the Elaner

[melmerby]

The factoty fitted Hornby DCC decoders* are also not paticularly good, too high track voltage can cause them to bolt.

 

EDIT *Applies to the non sound decoders R8215 & R8249

Edited November 18, 2021 by melmerby

[RAF96]

18 hours ago, melmerby said:

The factoty fitted Hornby DCC decoders are also not paticularly good, too high track voltage can cause them to bolt.

 

The XS suffix factory fitted sound are 21-pin ESU decoders, not the old and unreliable R8215 8-pin decoders often found in the X suffix factory fitted models.

Edited November 18, 2021 by RAF96

[melmerby]

3 hours ago, RAF96 said:

 

The XS suffix factory fitted sound are 21-pin ESU decoders, not the old and unreliable R8215 8-pin decoders often found in the X suffix factory fitted models.

Didn't spot the "S"

 

Agree about turning off DC operation

 

Post amended

Edited November 18, 2021 by melmerby

[Neal Ball]

On 17/11/2021 at 12:55, Grahame Ainge said:

I have a Hornby factory fitted DCC Kidwelly Castle R2897XS and although it works well most of the time, sometimes when the controller knob is turned (F1activated) the loco shoots off down the track (Bachmann E-Z Command Control). Any ideas please how to solve the problem since it can do a lot of damage when it unexpectantly happens?  As you may guess I'm pretty new to DCC. Many thanks, Grahame

There are a few things to try before chucking it all out and starting again. Sometimes a more systematic approach is better!

 

1. Determine first if it’s the decoder or the loco. Change the decoder into a different loco and vis versa.

2. If the problem still exits, have you tried a factory reset? CV8; set to 8. NOTE: check the instructions before you do this. You should be fine, but check first!

3. Try the loco on a friends DCC layout.

4. Talk to Hornby repairs dept they are very helpful.

5. If you have someone locally with a DCC layout, can you test the controller with one of their locos, on their layout.

6. As per 4, talk to Bachmann again they will be very helpful.

 

At this stage, I wouldn’t be throwing controllers away until I’ve checked above first…..

 

Does it only happen with this one loco? How many locos do you have? Is this the only one that’s sound? How many locos are running at the same time?

 

Good luck, I’m sure the answer is straightforward.

[Neal Ball]

Another thought! 
How clean is your track? Does it always happen at the same section?

[Brian]

Hi

Some good advice being offered, but some posts seem to forget you only have a Bachmann EZ DCC controller and are therefore not able to alter any CVs or carry out a  reset.

 

A good starting point for you IMO is to thoroughly clean all the rails and the locos wheel rims and check the wheel wiper contacts are clean and making good contact onto the wheels even when the wheels move slightly across the chassis.  Also ensure your means of providing rail power connection is sound and is not loose.     

Another option which costs just a few pence is to add a DCC Filter across the rails or across the DCC bus pair if you have a DCC Bus  This may help? reduce some corruption caused by spikes of higher voltage causing the decoder to miss behave. A 120R (120 Ohm) 3Watt resistor and a 0.1uF ceramic capacitor wired in series and then across the the DCC is worth trialling IMO it certainly wont hurt anything!

 

As stated, the run away is caused by the DCC decoder thinking the full rail volts DCC provides is full power DC and therefore makes the loco take off like the proverbial sculled cat!   The real way to stop this is to disable DC operation on the decoder, which you cant do!  But a model shop. friend with a better DCC system or even a local model railway club may be able to do for you. Once disabled you will not be able to run the loco on DC power of course. 

 

 

[Grahame Ainge]

Many thanks to everyone for the helpful replies. I did wonder if cleanliness of wheels might be the cause and will now give them an extra clean. Loco at present in works undergoing name and number change etc I am still only dabbling with DCC and this is my third sound loco. May not convert 100% due to expense of converting a large collection. Will contact my nearest model shop if I need to. They are excellent and I'm sure will be able to disable DC on the decoder. Will report back when problem solved.

 

 

[Neal Ball]

4 hours ago, Grahame Ainge said:

Many thanks to everyone for the helpful replies. I did wonder if cleanliness of wheels might be the cause and will now give them an extra clean. Loco at present in works undergoing name and number change etc I am still only dabbling with DCC and this is my third sound loco. May not convert 100% due to expense of converting a large collection. Will contact my nearest model shop if I need to. They are excellent and I'm sure will be able to disable DC on the decoder. Will report back when problem solved.

 

 

Good luck, I’m sure the answer is straightforward, just might take a while eliminating various issues.

[peach james]

Step 1:  disconnect EZ command
Step 2: go to local shop, buy reputable DCC controller.  NCE seems to be the flavor of the UK...though other options are certainly available.
Step 3:  Now you have a command station which isn't a piece of flotsam, you can diagnose the problem.  


EZ Command and Hornby Select are not really fit for purpose, IMO.  Even LDCC has more advanced features.  (LegoDCC, run on a RCX brick...).

James

[RobinofLoxley]

If you have fitted sound decoders, one such is more expensive than the controller you are 'using' to operate them. That alone should tell you something might be wrong. The bolting is just the first symptom of problems, there are going to be others until you change the controller. You will get different views here as to what you should buy.

[Nigelcliffe]

As with other recent posts, if this is "the third sound loco",  then your next purchase should be a new, decent, DCC system.  

There are lots of options at or below £200. 

Some for as little as £25 (which will involve some limited DIY electronics and computing skills).     

 

 

- Nigel