Adams DCC decoder fitting

[ColinB]

I just taken delivery of a Hornby Adams loco. Chrissaf is going to complain about this, but the space for fitting a DCC decoder is awfully small. The thing that hit me having fitted one in the Oxford version, is why did Hornby not make a hole into the coal bunker so you could fit the decoder there. From my experience of Hornby decoders (TTS and normal) they are exceptionally prone to being damaged if they cannot dissapate the heat, especially if the motor goes into a stall, so trying to fit the decoder in a relative small area is not a good idea. Yes, I know I can drill a hole through, but I shouldn't have. So does anyone have any ideas why Hornby didn't do what Oxford did, and make it such that you can fit the decoder in the bunker, there is plenty of room. Oxford even put cooling holes in the underside to aid cooling.

[Chrissaf]

Chrissaf is going to complain about this

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Whatever for? [rhetorical question - one that doesn't require an answer].

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Nothing wrong that I can see with the post.

[Bulleidboy]

As discussed previously, the TCS DP2X-UK decoder will fit in the Adams - this is a direct fit decoder with no harness and plug. You will find it virtually impossible to fit a Hornby decoder.

 

Remember that some R3333 and R3334 models had the socket incorrectly wired.

 

It would be fairly straightforward to remove the "base" under the coal load to give more space for the decoder, but why should you need to start chopping a new loco about as soon as you get it?

[ColinB]

I wasn't going for a Hornby anyway, I have had too many issue with them failing as I said previously. I think they have a thermal issue which in limited spaces will get even worse. I will probably go for a Zimo, for jobs like these I use MX617 and solder my own 8 pin plug on it, it is only slightly more expensive than the Hornby one and a lot more reliable. I was just commenting that Hornby could have made things so much easier and I am still trying to figure why they didn't. I can see you might want to add your own coal, but then there are issues with the cylindrical part fitting in the bunker. I always do a continuity check before I fit the DCC decoder, I have been caught out too many times before, but thank you for warning me.

[Bulleidboy]

This thread prompted me to dig the Adams out from the back of the cupboard and have another look at it. I installed a TCS decoder, and programmed it and placed the loco on the rolling road - ran perfectly. I then tried a Hattons budget (£10) direct fit decoder. It would only operate with code 03 - it would not accept any other codes - I tried two different ones. It ran perfectly, in both directions, until I replaced the body, then as before, it moved an inch and stopped, moved an inch and stopped - it did this for the length of the track. Now the decoder code is nothing to do with the loco - I fitted a Hattons decoder to one of my Merchant Navy class and it would only run in reverse - but that is another story. So as far as I am concerned the Adams will not run properly with the body on. It's about to go back into its box and back in the cupboard.

[ColinB]

You have me worried now, not about the Adams but the decoders. Most of my decoders are still set at 3 until I finish the layout, so I check the loco on DC then DCC, but other than a few, virtually all of them are set at default value of 3. I must admit I have tried lots of decoders I have found the Zimo ones to be the most reliable, the others Hornby, Hattons, Gaugemaster, DCC supplies all seem to fail for no valid reason. Two of them failed driving Ringfield based locos, but the currents were all within the limits of the device. I had several DCC Supplies 6 pin ones (they are the only ones that would fit) die when driving some old Bachmann locos I converted, again the currents were within spec, replaced them with Bachmann decoders and no further issues. So far other than when it is my fault, I have not had a Zimo fail. I think a lot of the problems is the components they use are near their limit as far as thermal stability is concerned, so I come along put in a sleeve to avoid it shorting out but at the same time reduce its ability to get rid of the heat.

[Bulleidboy]

We are going off topic slightly, but I think nearly all of my "operational" loco's - I have about twelve sitting on the layout (this includes a couple of EMU's), are all fitted with TCS decoders - in most cases the DP2X-UK. I have not had any problems with them at all - and they do have a life-time guarantee. Using this decoder is down to ease of fitting. Having visited Florida each year for the last eleven years, a visit to the local model shop meant that I was purchasing TCS decoders every year - they worked out at about £20, which was cheaper than buying them in the UK.

The problem with the Adams, as far as I can see, is that with the decoder in place (have tried both the TCS and Hattons own direct fit), when the body is re-fitted, the base of the coal bunker, touches the decoder - enough to stop the body sitting properly. I can see that the underside of the loco - beneath the decoder, is not fitting perfectly as it does when there is no decoder fitted. I should have added that the Hattons decoder comes fitted with a protective sleeve which is marked showing Pin 1. 

I use a Hornby Elite (1.45), and most of my loco's have either three or four figure codes - usually matching the cab side number. I've not had any problems setting these up except for the Hattons decoders.

I'm not sure what to do next, other than to give it up as a bad job.

 

 

 

[Ruffnut Thorston]

In general, it is better to insulate any metal parts in the area of the decoder, rather than wrap the decoder.

 

Of course, Hornby supply sleeves...and some decoders come ready wrapped.

 

Fitting decoders in steam locos does seem to be more involved than diesel and electric locos...which are bigger boxes.

 

It doesn't help when a loco is made so only a very limited range of readily available decoders will physically fit...Hornby Terrier for one example...

 

If only "DCC Ready" was just that, plug and play! 😉

 

 

[ColinB]

Trouble is Sarahagain you are putting the decode into an area where there is a load of metal. Quite often you figure where it is going to go, but it moves as you put the body on. I have damaged several decoders where it works perfectly ok without the body on but then when you screw the body on it fails. 

[ColinB]

Coming back to the original post, having looked at it for a while, the easiest solution for me, is to cut the end off the decoder put it in the bunker and thread the wires through the holes at the bottom of the bunker and then reattach the wires onto the 8 pin plug in the DCC socket area. Not ideal but it will work. We only need 4 wires, so an easy soldering job. If I use a Zimo MX617, the one I like (the one you can add stay alive to) comes with a 6 pin plug on it, so I have to rewire it anyway. If you remove the body in the future you just have to remember to disconnect the DCC plug. Putting the decoder in the bunker means it has lots of air and plastic around it so no shorting or thermal issues. I could cut a hole and not rewire the plug, but the hole would need to be quite large.

[96RAF]

Is there not the option to simply cut a slot Colin so just the harness has to slip in rather than having to feed the great big plug as well.

[ColinB]

Trouble is the slot has to be decoder width. I think possibly use a 6 pin decoder in the bunker and have a 6 pin to 8 pin converter lead, then the slot only has to be the width of a 6 pin socket. Wiring the 8 pin is not an issue for me, I think that might possibly work. 

[ColinB]

Well it appears I have a very simple solution. I was adding a sound decoder to Bachmann Standard Class 4mt as a favour for someone. When I took the old decoder out, I thought that looks really small. Anyway it fits perfectly into an Adams. What I suspect it is, is a normal N gauge type, I assume from the same makers as LokSound, that was the sound unit I put in (I think the guy always uses that supplier) that has had an 8 bin plug soldered on in place of the 6 pin plug. It fits perfectly. I think the trick is to make the lead short enough to bend, but not long enough to take up too much room.