ColinB

Thank you Sarahagain for the information. I wanted some wheels to replace the traction tyred ones on the Jinty style chassis and the J94 ones are the cheapest.

One thing I would suggest if you are fitting the speaker in the tender, there is this guy in Leeds on Fleabay that sells very small Iphone speakers, not only do they fit easily in the tender but they sound pretty good. They are really thin, so fit under the bunket which most speakers won't, I use them all the time. Not only that but they are really easy to insulate.

The thing is surely they must be 12 volt motors or else his previous decoders would have fried them. DCC drives the motor with a PWM signal, with I assume 0 to 12 volts, so a 3 volt or 6 volt motor would probably over current taking the decoder with it. He says it works properly, it is just the reading wrong on his ammeter. 130 milliamps is not much current, I am sure even a CD mechanism must draw more than that, remember it is hauling an HST, and from my experience quite a heavy load. Anyway the motor is the other side of the DCC decoder as is the leds etc. The only thing sits on the DCC bus is the TTS decoders input stage. Sorry I suspect the ammeter on the Powercab, why you would want one amazes me, it is not DC it is a modulated AC signal.

Is that 0.13 or 13 Amps, if it was 13 Amps you would have one fried HST module. You don't say whether the loco still runs when you get this magic value. If you had a short, nothing would work, the only thing that might be happening is the HST wheels getting stuck in the points frog causing the motor to stall, that would give a high current value. 0.13 wouldn't be right either Ringfields according to my tests consume about 250 milliamps (0.25).

It is probably the gear stuck if the motor is buzzing, check the valve gear for stuck linkages.

No DCC decoders don't cause "run away" but poor software does. Generally the average user is not going to change from DCC to DC in milliseconds, probably more like 10s of seconds, so you just put a timer in the software to exclude the switch to DC operation from DCC if the time is less than a certain value. I used to write embedded code software, believe me it is not difficult. Does your car stop, everytime you switch on the aircon or go past a radio mast, no because someone like me told it not to. Why is it some decoders cope with an intermittant signal better than others, lets face it and decent designer should be using that as part of the design criteria. Fortuanetely, I use decoders that don't seem to have these faults my only exception is the TTS decoders and I only use them because they are good value for the money, so I am willing to accept their faults. Back to the original subject, what you need to do unfortunately, is take the loco apart and check all the soldered connections, I had this sort of fault on a Oxford Adams, but I was unluckier than you, I killed three decoders basically going round bends. What it ended up being was the wheels touching a soldered joint connected to the motor. So basically I was feeding the raw DCC signal to the motor, which virtually always kills the motor. So in your case you need to do that check as soon as possible. It could be the wheel has cut through the insulation on one of the wires, they are very thin.

Does anyone know the diameter of J94 wheels? Are they they same size as Jinty, J13, J52 and general 0-6-0 locos? Thanks.

Possibly since this thread is 4 years old, people didn't understand DCC like they do now, perhaps the diodes in the bridge rectifier were not quite as good as they should be, we know Hornby generally design to the limit with very little thought to redundancy. Also electrolytic capacitor do degrade with age and we also know that Hornby seems to get batches of duff capacitors. I imagine on a modern one, there should not be any simlar issues. Diodes are so cheap, just replace the lot, similarly electrolytics don't break the bank so replace those.

Peters spares is selling S4581/2 on Ebay. Now I know he hasn't any of the non sprung types, as that is what he told me, so I have no clue which one refers to which. I would like to get an unsprung one, but I haven't a clue what to search for and most people when advertising don't show the underside.

Do they, but he is talking about something a bit older, so I assume it still works. I must admit I have stopped using Hornby R8249s, I tend to use Zimos, they are slighly more expensive and less prone to failing. I must admit I used to think decoders were all about the same until I had a loco with dodgy pickups ( I had to make my own as I couldn't get replacements). With the Zimo it behaved faultlessly, with two of the other types it stopped and started and hardly worked. There seems to be a diffence in how they handle missing signals.

Thanks that is great, generally I just check I get a number, but in this case I want to know the manufacturer as the decoder is unknown to me.

From what you said it is dcc fitted, it is really only TTS decoders where the DC gets disabled, so yes it should run on a dc supply. That in fact is one of the tests I do when I fit DCC. The most important bit though is the controller that you use to generate the dc. If it is the old sort like the old Triang ones or H and M type that we used to use in the past, there is a fair chance it will blow up your DCC chip, note I am talking from experience. The regulalation in these is not good enough, although they are supposedly 12 v output, you can get peaks of 18 volts which kills your average Hornby DCC decoder and many more other makes. So if your controller is the modern type, lets say taken from a Hornby trainset, then no issue. Hope that helps.

Can anyone point me to a table of DCC decoder manufacturer identifiers. The value you read from CV 8.

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.

S4581/1 is the sprung one that takes the motor with both pickups attached to the motor housing, I know I just bought one. So I think S4581 is the one where the motor housing only has pickups on one side. I assume the one without springs is S4581/2 but Peter's Spares said they didn't have number for it. If they put the part numbers for these things on Service Sheets, even if they are not available as spares (they could put that in the comments), it forces people to maintain correct records, because rather than one person checking it in an office there are thousands of people checkiing it for you, for free.

This is an 4-4-0 configuration, correct me if I am wrong. One of the issues is unless there are pickups on the front bogie it is only one axle on the loco that is of any use as a pickup, as the driving axle has traction tyres. I had loads of issues with my Schools class which is the same configuration. In my case because of the way the loco bounces around the track the Loco to tender pin had a habit of jumping out, so the previous owner had "peened" the pin over so the loco and tender were permanently attached. Unfortunately, this had the effect that the tender did not sit properly on the rails, so the loco didn't work properly, to fix it I extended the drawbar. So in your case, check all the tender pickups are working, basically measure the resistance between wheel and pickup. If the drawbar has those finger connections check that they are making good contact. Check that the tender is sitting nicely on the rails. On these locos, the tender pickups are more critical than on other locos. The shooting off at top speed is an unwelcome feature of TTS, normally you have to disable the DC option. To me it is a bug that needs fixing, but certain members on this forum say I am too critical. Hornby did the "bodge" and simply disabled it, on newer locos. TTS is also more critical of the signal than normal decoders, so will find it losing the DCC signal where other decoders don't.

No, they don't that was the firm, that I was refering to, but I didn't want to mention names. The sprung one also has the part number S4581, see how confusing it is. Anyway changed the worm wheel to a new one and the loco appears to be working properly. The other one I was building out of parts, it appears the "new" set of wheels I bought from another supplier, not Peters, had a worn out worm wheel. I wish I had known, I damaged a brand new motor trying to get it to work. It is not until you see a new one you realise it is damaged.

Yes eventually by trolling through the Service Sheets I found the right one. I took the two 0-6-0s apart ready for when the new drive gears arrive, one has a chassis with springs one without. They both have their part number cast into them, surprise, surprise they both have the same part number. Obviously Hornby never got round to removing it from the mould, what is worse than having no part number, it is having the wrong one because you think you have the right part, believe me, I used to work for automotive and that is really serious. Anyway I thought I would change the sprung chassis to the new one, so I emailed the specialist Supplier to see if they had one, but they don't have one. When I asked what I needed to search for on their website to check see when they have got any in, I was told they don't have a part number for it. So how on earth do you do a search in this digital age, if you have no part number. It appears dinasours are still alive and kicking.

I have started to take my J52 apart so that I can replace the worm crown gear and there are some really funny things. This is a relatively new loco compared to some of my old ones because it has the split conrods with hexagonal nuts. First thing that hit me was the chassis didn't have the springs on the third axle, but it has the same part number with one that does (it is stamped on it). The centre wheels don't have traction tyres, but that could be someone replacing the centre wheels, but the crown wheel itself has a part number stamped on it of L5714 but it is black not white which seem to have the same part number. So next question is did Hornby stop using the spring loaded third axle on some variants.

Oh, great thanks for that.

Great thank you for the advice. Sadly X8199 is not currently available, the only place I could get it was from a Seller on EBay and they are a different colour but I can live with that. I don't think I had better mention about the lack of spare parts it constanly winds me up. I could put it down to Covid but sadly it is a more underlying issue. Trouble is with the lack of spare parts the second hand market will fold which eventually has the effect that you cannot charge as much for the new models. I have seen it happen in the car industry.

Is it a common problem with 0-6-0 locos where the work gear stops meshing with the crown gear? I was updating an old Hornby J13 with the old X03, so I bought a new base wheels and motor. When I built it the motor wouldn't mess properly with the gear, so basically the motor ran without turning the wheels. So I just put that to one side and bought a second hand J52 0-6-0 complete, put DCC into and got it to do a couple of circuits of my layout. Surprise, surprise the motor stopped messing with the crown gear and the motor now runs without driving the wheels. As far as I can see there is no way or adjusting the motor other than putting packing pieces in. So is it just a bad design or am I doing something wrong. I will add I did nothing to the J52 other than greasing it and adding DCC. Of course Hornby no longer do the worm and pinion as a spare part.

What I did with a couple of my Duchess locos was to just buy the newer tender bottom, I don't know if they do the tender bottom for the Black 5, and the 4 way lead. Then you can move the electronics to the tender. Have a search through Peter's Spares to get ideas.

Yes Fishmanoz you are right and yes if it is easy to remove it then do it, but if if means hacking at the loco wiring then don't, not that the capacitor is needed it is just that you are risking damaging something else. As I say if it is on a Hornby loco try and remove, they are lots of posts saying where the capacitors give issue ( I think they must have purchased a duff batch), but it is such a small value, all it will do is slightly round the PWM edges that get fed to the motor.

I would have said no it does not invalidate the warranty. How else are you supposed to fit the DCC device without taking it apart? I have said for a long time that the manufacturers should make fitting the DCC decoder as easy as possible to avoid getting broken locos back, I used to design equipment digital test equipment and the last thing I ever wanted was getting it back broken, some people like it as it makes them feel important. The trouble is on a modern loco, soon as you try to remove the body, unless you are ultra careful, ancillary bits fall off. Unfortunately, most manufacturers haven't quite got to grips with the digital age and customer rights. Next time test the loco on dc before you take it apart, it solves a lot of issues.