Decoder for Stephenson's rocket R3810

[RB51]

Please advise on best decoder to buy for Stephenson's rocket, r3810. My model is due to arrive in the next few days.

Many thanks

[Chrissaf]

Question has been asked before and answered extensively ... see this previous thread (copy and paste link text below):

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https://www.hornby.com/uk-en/forum/new-rocket-and-dcc-decoder-/

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[MartKS1707822133]

I just used the 

HORNBY R7150 Standard 6 Pin Decoder 

fits nice. I know alot have had problems fitting it, I just put mine in side ways fits like a glove and

barrel flush fit.

[Ken.lner]

Many thanks for the replies and advice.  I shall look at the threads over the bank holiday.  Thanks again.

[ColinB]

As I said in a previous post, I used a 6 pin wired (you need it wired so you can wrap it) Zimo decoder from YouChoos, the £20.00 special. It is slightly smaller than the Hornby, not that it matters for the Rocket but it also has a better specification.

[Lightray]

The previously mentioned R7150 chip I found is really a shade too big and was an extremely tight fit for me. It is the wires that need room and can impede getting it all shoe-horned into the barrel. The plug pins are too long as they come and made the fit wider than the barrel space as standard. I had to cut the pins shorter to make it work. As someone elsewhere has mentioned it is also very crowded and heat would not be disipated well so may cause problems. I've not run it long enough yet but I have noticed a couple of cutouts maybe caused by the onboard overload protection. My version of the chip had a sticker on the packet saying it was suited to the Peckett B2 and new Terrier. No mention of the Rocket!

Overall I would say that  probably the Zimo small decoders are  a better fitting option with better specs.

As a general point to Hornby it would be great if the on-line item descriptions for all DCC decoder products included the specification for which locos they are suited to, their power handling characteristics and their dimensions were given in the description.  Also even better, a downloadable pdf of the instruction sheet would help. Thanks

[96RAF]

There are already downloadable instruction sheets for R8245 Sapphire and R8249 basic decoders.

R7150 is essentially an R8249 with 6-pins. whilst updating the decoder product page to include ‘suitable for...’ information may seem to be a good idea this would only be of use for specialist locos as the list for say a basic 8-pin decoder would go on forever.

Neither would do any good to carry this listing over onto the paperwork with the decoder packaging as it would be out of date before it hit the shops due to mew models being released.

Then some folk would want the list expanded to include all other international and other brands, etc.

[ColinB]

I must admit with all the decoders it is really difficult interpreting the specifications. A lot of them are incredibly optimistic, I suspect they are quoted for testing the decoder in "open air" where it has adequate cooling. I have converted a lot of my old Bachmann and Hornby locos so I did the stall test. I then selected the right decoder decoder according to the requirements and then managed to destroy them with "overcurrent". When I mailed one manufacturer they said it must be an overcurrent issue, since then I no longer use their products. Sadly, although I don't like doing it, I stick to the German and Austrian products as their specifications seem to be correct and if I want to know more I just mail their Supplier and I get a true valid answer, the others even if I get an answer it is usually from a sales person rather than real technical support. I tend to use only one supplier for decoders, if you read my posts you will gather which one it is, they are they only ones that have only failed when I have done something stupid. The only deviation on this policy is TTS decoders, but you have to be so careful with these.

[96RAF]

You would have to do a bit of adaptive modelling to fit TTS to the Rocket and even then the sound set will be totally wrong. Just saying.

[Mar Mallard]

I must admit with all the decoders it is really difficult interpreting the specifications. A lot of them are incredibly optimistic, I suspect they are quoted for testing the decoder in "open air" where it has adequate cooling. I have converted a lot of my old Bachmann and Hornby locos so I did the stall test. I then selected the right decoder decoder according to the requirements and then managed to destroy them with "overcurrent". When I mailed one manufacturer they said it must be an overcurrent issue, since then I no longer use their products. Sadly, although I don't like doing it, I stick to the German and Austrian products as their specifications seem to be correct and if I want to know more I just mail their Supplier and I get a true valid answer, the others even if I get an answer it is usually from a sales person rather than real technical support. I tend to use only one supplier for decoders, if you read my posts you will gather which one it is, they are they only ones that have only failed when I have done something stupid. The only deviation on this policy is TTS decoders, but you have to be so careful with these.

I love a TTS but which on earth would you fit into a rocket??

 

Just to be clear, consensus is Zimo MX617F (6-pin wired)?  Unfortunately they are completely unavailable!!

[ColinB]

Yes, you are exactly right they are out of stock everywhere. Hopefully they should soon be in stock again. Trouble is I get the opinion nobody has made anything since March.

[Mar Mallard]

Yes, you are exactly right they are out of stock everywhere. Hopefully they should soon be in stock again. Trouble is I get the opinion nobody has made anything since March.

Any equivalents?  Surely it is just a small 6pin decoder?  I am no decoder expert!!

[ColinB]

I don't know, it is the size that is most important, I suspect any N gauge one should do. I found this one https://www.coastaldcc.co.uk/products/lenz/decoders/n-gauge/   it is a bit expensive but it looks small.

[Lightray]

I appreciate RAF96's response aand I can understand you can't necessarily specify 8 pin generic decoders for locos. However I still think it important for Hornby to consider giving two specs in their details. The most important is the dimensions of the chip as this determines fit in a lot of small locos (Hornby makes a lot of these too). The other would be average and peak current handling. Granted that a lot of modern loco motors have lower power requirements. Still these are specified by all manufacturers and most suppliers so Hornby is lagging behind in this area. Clearly the continuation of a small 6 pin is important for the numerous small tank locos (and Rocket!) that have tight space inside and thus dimensions often become critical.

It is clear in the market as a whole that DCC is growing in popularity and use and Hornby's budget TTS have really made their mark in this area for a start into sound. However it would be great if the above two specs could be added to non sound chips and for all TTS the dimensions would be a great help. Thanks

[96RAF]

I am not quite sure what else Hornby could add to their decoder spec as the criteria you have asked to be published is already there...

 

/media/tinymce_upload/2361bfcfdf8de1b8bdb6dde8b71c3815.png

 

Dimensions of course are only of use if the decoder is direct fit. If harnessed then the wire length becomes important.

[ColinB]

Usually it is not only the size of the decoder that matters it is also how much wire it has on it that seems to make a big difference. The Hornby decoder would probably fit into a lot of locos but generally you cannot accomodate the wire. The Rocket it appears to me is probably one of the few locos where they did actually put some thought into getting a decoder to fit, sadly not one of their own, but at least they tried. On a lot of their locos I get the opinion the socket was put in as an after thought (try the Adams). As to the decoders, I found there are better ones with a higher spec. for roughly the same price, but I have found that with many of the well established brands. TTS decoders are good value for money, but in my opinion seem to have reliability issues. I get the opinion a lot of it is to do with heat transfer, or lack of it and some undocumented features. A lot of the more modern decoders have current limiting, even a cheap one I bought from Taiwan had it, so it is a little more difficult to kill them, again sadly a lot of the established manufacturers decoders don't seem to have this. You would have thought Hornby would be addressing this issue with some urgency, as a lot of die hard Hornby users would naturally try fitting them to their old locos, that draw considerably more current.

[96RAF]

TTS is based on the spec pictured above which clearly states - motor overload protection. It is the functions that are not self protecting.

[ColinB]

It probably does have motor overload protection, but I think it has issues with heat disapation when it goes into overload, which eventually kills it. At least three of my TTS decoders have died because of motor overload, twice when the motor capacitor went short circuit and I suspect that was the reason my HST one died. I think the Taiwanese one disabled the drive, flashed the front lights (if they were connected) until you reset the DCC.Unfortunately, I am not brave enough to test it out on a TTS decoder, I have sent far too many of them back to Hornby. The reason I know about the Taiwanese one, was I converted my Triang EM2 to DCC and that was the only one that would handle the current. Either way, I am incredibly careful how I fit TTS decoders, making sure they have adequate air flow over them and sufficient insulation so they don't "short out" on any metal parts. I would have liked to fit them to some of my old Lima locos, but that is a risk I don't want to take.

[Howbi]

Colin you must be doing something radically wrong in handling your model railway. In the 10 years I have been contributing to this Forum you are outstanding in being the numero uno Decoder killer either through carelessness or lack of knowledge of the products. You do tend to make assumtions and speculate quite a lot. It is more helpful to the Forum if you would just stick to commenting on factual information.

 

Maybe you should take up a less stressful hobby like knitting or spoon whittling 😆........HB

 

p.s.........just saying in a friendly manner, please don't take the wrong way.

 

[ColinB]

Great howbiman that is best piece of rubbish I have seen this year. I can tell you exactly how all of them have failed and yes I have owned up to killing a few, generally by not being careful enough. Now the ones that failed because the locos capacitor goes short circuit is that my fault, the one where the sound decides to switch off after one circuit is that my fault (in this case Ity was factory fitted), the one where it suddenly decides it will only do sound every 3rd or 4th power on. In actual fact when I think about it I don't think I have killed any of these, most have died when in the loco running along the track. They are normally insulated the only one I did kill by my fault was when I used one of those 21 pin to 8 pin adaptors which was too high. Generally most of my speculation comes from analysing the components on the decoder, generally I know what they are and 30 plus years of knowing the weak points. So please just keep your opinion to yourself, unfortunately I find your attitude very offensive. I also compare those with the decoders that give me no issues.

[Howbi]

Oh well, you could have just joined in with the banter, a sense of humour goes a long way.........HB

[ColinB]

Well it did not sound like that to me. Actually when one dies that is my first thought "what did I do wrong", but just lately all I do is put the loco on the track and run it. After the HST failure I have even been going round making sure that they all have adequate airflow over them.

[Fishmanoz]

Colin, I too think HB should be more careful with his suggestions. 

After all, trailing wool is sure to catch and damage something around the layout and Murphy decrees that whittle shavings (or is that spoon shavings) will get caught in the most inconvenient places - I would think drive trains. 

[96RAF]

Oh well, you could have just joined in with the banter, a sense of humour goes a long way.........HB

 

The problem with banter Howard is that you must know someone well before you insult them so.

Any ex-RAF/Navy/Army - always knew their best mate as they would give you the most stick knowing you would not be offended. Anyone who took offence was quickly excluded from ribald crew room banter, often ending up as Billy-No-Mates.

 

 

[Lightray]

I am not quite sure what else Hornby could add to their decoder spec as the criteria you have asked to be published is already there...

 

/media/tinymce_upload/2361bfcfdf8de1b8bdb6dde8b71c3815.png

 

Dimensions of course are only of use if the decoder is direct fit. If harnessed then the wire length becomes important.

Hi - I think this has just proved my point. This is a copy from the instruction/spec sheet that comes with the decoder. My point is that the spec is not on the website, that I could find, neither in the service sheets nor on the product page itself which would be the most sensible place for it. Also as this is a discussion for the Rocket and Hornby's fit R7150 decoder it happens that the dimensions are critical to getting it in or not. As I said before I had to clip the pins of the 7150 to get it to fit.

Since RAF you have said elsewhere that Hornby don't look at these pages - how is the best way to make a suggestion for improvements to Hornby?

Thanks