R3544 - LNER B12

[NESteam]

 

Does anyone have any experiences with the R3544 Hornby LNER B12 loco (the one with running number 8527)?  

I bought one (from Hattons) in February, and initially it was fine, but after 2-3 weeks elapsed (only 2-3 hours running time) found the motor to get very hot , and emit an electrical burning sort of smell. This was running on a DC layout powered by HM2000 controllers. I contacted Hattons, who replaced it (very quickly).

The replacement seemed fine, and I have subsequently updated to DCC, powered by eLink & Railmaster.  I fitted all my locos with Lenz Standard V2 decoders, and all was well, except for my B12 - this ran erratically at times, and while trying to work out why, it stopped dead.  I found I could read the decoder CVs on the programming track, but it would not respond to any motor control on the main track.  I replaced the decoder (another a Lenz Standard, which is what I had avaiable), and the whole process repeated - eventually killing the replacement decoder too.  So, I ordered and fitted a Hornby R8249 decoder.  Things were better - although the motor makes a weird creaking/groaning noise at very low speed - until this morning.  The motor is running very hot, and there's a faint whiff of that burning again.  The loco also stopped dead, as it did with a Lenz decoders, but this time it recovered - Railmaster reported a short circuit, which if correct, must have been within the loco/decoder.  So, I am now assuming that short circuits wrecked the 2 previous Lenz decoders, but the Hornby one withstood the short.

So, could the hot running cause a short within the motor and/or internal wiring (note on this model, the decoder is fitted in the tender so won't be affected by the hot running moter), and, why might 2 brand new models start to run hot after several weeks?  Any comments, thoughts or ideas would be most welcome.

[Chrissaf]

Whilst you wait for a reply, perhaps you would spend a few minutes reviewing the TIPs in the TIP page link below:

 

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[ColinB]

Sounds very weird, what you could do is remove the motor suppression capacitor, that might be causing some issues, I have had one go short circuit on me. I suppose the only other thing is that when they built these, they had a bad batch of motors but that seems unlikely. B12 don't have much valve gear so it can't be that getting jammed causing the motor to overheat. Have you tried asking Hornby?  A duff motor suppression capacitor definitely would take the decoder out. Surprised a Lenz failed and the Hornby didn't, normally it is the other way round.

[GWR 14xx Tank]

My GWR Class 101 - bought from that very familiar auctioning site - has the same sort of symptoms to yours too. Does yours slow down drastically after a few minutes running? Mine does every time I run it.

 

14xx Tank

[NESteam]

Thanks for the response ColinB, much appreciated.  I have contacted Hornby and await a response...

GWR 14xx Tank: What you are experiencing is pretty much what I had with the Lenz decoders fitted.  Mine runs fine with a hornby decoder fitted - until it gets hot, shorts and stops dead!!!

[Going Spare]

Putting aside the involvement of DCC about which I know very little, under traditional control a motor that is overheating either has an internal fault or is being put under too much stress.  From the Service Sheet, the B12 appears to be unusual in that its motor is driving the worm via a short shaft and thence via transfer gears kept in place by a coverplate, and is held in place by a cradle gripping it around the bearings at each end inside the two flywheels.  I appreciate a degree of disassembly would be involved - which you understandably may not be keen to undertake on a new loco - but I wonder whether everything is able to rotate freely and/or is adequately greased/lubricated.

[96RAF]

Given the loco is new the responsibiltiy to fix or replace it still lies with Hattons, not Hornby. Fortunately Hornby seem to take the benevolent view that if the retailer is not playing ball they will deal with it instead, but usually they need proof of purchase, which is understandable.

 

You could also claim replacement decoders from Hattons on the strength of the fault inducing their damage, but I can’t see Hornby falling for that one.

[ColinB]

I know you are supposed to talk to the retailer, but the problem here is that they are not really going to help much. Unless you are lucky, they are not that technical, there are basically a shop. The only thing they can do is send you another one which they already have done. I bought a DCC Concepts DCC decoder, when it arrived, there was no way the lead they supplied was going to fit it. I phoned the retailer and they said I could return it, or basically bodge it. So I phoned the technical people at DCC Concepts, they were very good, what had happened was the wrong lead had got packed and they sent me the right one. So sometimes it is better to talk to the people that know. I could tell many stories about customers getting "fobbed" off in car dealerships about known issues with their cars, when the fault is well known by the manufacturer. It is not always the Dealers fault, quite often they just don't know.

[NESteam]

Just to finish this thread off - I have not contacted Hattons again, as all they could offer me was a) a replacement, which they already have done once, and I have the same issues, or b) a refund, which I don't want, because I like this loco and I just want it to run reliably.  Hornby are being benevolent (as predicted by RAF96), and they will take a look at it, once all this lockdown palaver has eased.

Given that the Hornby decoder seems to withstand short circuits (which the Lenz decoders didn't), I have run the loco a few times over the past week or so, if only to get a consistent picture of the behavior to pass on to the Hornby repair folk, and, it appears that, straight from the box, the loco will run for 4-5 hours (run time, not elapsed time) before the problem rears it's head.  Then, it will start running hot, and presumably the heat causes some expansion of metallic parts, and we get a short.  The loco will not then run until it has cooled (allowing the errant metallic parts to contract), after which it will run for no more than 5 minutes before it shorts again. Actually, this is not strictly true, as if I try to run the loco again straight away, it will attempt to move, but just a little jerk, then stop dead again.   I have looked at the service sheet for the B12, and I'm convinced  GoingSpare has hit the nail on the head - the gearing mechanism is not free moving - perhaps the coverpate is too tight?  I think I'll let Hornby sort it out, as even if I could properly diagnose the fault, I may not be able to fix it.

Once again, thanks for the comments - very much appreciated.

[GWR 14xx Tank]

Thanks for the response ColinB, much appreciated.  I have contacted Hornby and await a response...

GWR 14xx Tank: What you are experiencing is pretty much what I had with the Lenz decoders fitted.  Mine runs fine with a hornby decoder fitted - until it gets hot, shorts and stops dead!!!

I probably should have clarified that I am DC only.

 

Eventually found out that it was a problem with my controller's thermal fuse overloading and shutting off - seems weird still though - much bigger motors in engines never cut out with it. Have now bought a new controller.