Oxford Rail J27

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nzpaul
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Re: Oxford Rail J27

Post by nzpaul »

A little bit of proper diagnosis required I think. Running on dc does it actually run fine? Can you test it to make sure the motor is drawing correct current? usually around 100mA for a loco with no load.
Dc locos on dcc are a dodgy proposition at best. Try removing the blanking plug and continuity test the wiring.
Pickups and motor wired to correct pins, plug removed should isolate the motor from the pickups. Put in on the dcc track with the blank plug removed and you should get around 14v ac at the pickup pins and no response from the motor. All being well fit a decoder and check response on the programming track. Set the address and most decoders will cause some motor reaction while the CV loads. Make sure you can read back the address to verify the chip etc.
If all that fails, maybe best to take it back and ask them to have a look. Good luck.

Paul
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Re: Oxford Rail J27

Post by Hatfield Shed »

73082gibbers wrote: Mon Jan 24, 2022 11:55 pm they put it on their DC layout, and it ran fine...
So given a DC supply it works normally. This suggests there is no problem with the mechanism. Erase all thoughts of a short on the loco.
73082gibbers wrote: Mon Jan 24, 2022 11:55 pm ...I then proceeded to try and chip the loco but thought, as I had a Bachmann EZ DCC controller, which has a number reserved for DC locos, I'd try the engine out on that. It proceeded to just splutter along, with no power applied on the dial, with all of the controller leds flickering. Should I try taking it back to Kernow again, or is there a common problem inside the loco body that could be causing a short on DCC?
As 'nzpaul': have you installed a decoder? If so, the first and only thing to do is to immediately use the programme facility to check the decoder installation by changing the decoder address. If that's successful, then run the loco on DCC to assess it. Pretty sure you will find it runs properly, as what you describe on 'Address 0' is the motor attempting to run

General note, the old 'Address 0' facility provided on some DCC systems was to encourage modellers to give DCC a try by making it capable of running a DC loco, and is long obsolete. The larger iron core motors typical at the time DCC was introduced could tolerate the hammering the DCC waveform dished out; current smaller iron core motors, and even more so the increasingly common coreless types such as fitted to the J27 are liable to be damaged very rapidly. Seriously, you should put a label on the system controller reading 'DO NOT USE ADDRESS 0!'
73082gibbers wrote: Mon Jan 24, 2022 11:55 pm ...was attempting to have it test ran on my local club's test track. Now this test track is DCC but can accommodate DC locos on it. On placing it on the track, it caused a short on the test track, so was moved onto a programming track, and it turned outthe that it was the loco at fault...
I wouldn't test anything on a club track unless I was very sure of the wiring and supply integrity, and know how of the club member(s) operating it. Putting a DC loco on test on a DCC programming track suggests a serious deficiency in understanding. That will immediately generate a 'fault' reading, as with no decoder present the test signal is shorted. So your model is fine, as the subsequent DC running proved.
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73082gibbers
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Re: Oxford Rail J27

Post by 73082gibbers »

Hatfield Shed wrote: Wed Jan 26, 2022 11:04 am
73082gibbers wrote: Mon Jan 24, 2022 11:55 pm they put it on their DC layout, and it ran fine...
So given a DC supply it works normally. This suggests there is no problem with the mechanism. Erase all thoughts of a short on the loco.
73082gibbers wrote: Mon Jan 24, 2022 11:55 pm ...I then proceeded to try and chip the loco but thought, as I had a Bachmann EZ DCC controller, which has a number reserved for DC locos, I'd try the engine out on that. It proceeded to just splutter along, with no power applied on the dial, with all of the controller leds flickering. Should I try taking it back to Kernow again, or is there a common problem inside the loco body that could be causing a short on DCC?
As 'nzpaul': have you installed a decoder? If so, the first and only thing to do is to immediately use the programme facility to check the decoder installation by changing the decoder address. If that's successful, then run the loco on DCC to assess it. Pretty sure you will find it runs properly, as what you describe on 'Address 0' is the motor attempting to run

General note, the old 'Address 0' facility provided on some DCC systems was to encourage modellers to give DCC a try by making it capable of running a DC loco, and is long obsolete. The larger iron core motors typical at the time DCC was introduced could tolerate the hammering the DCC waveform dished out; current smaller iron core motors, and even more so the increasingly common coreless types such as fitted to the J27 are liable to be damaged very rapidly. Seriously, you should put a label on the system controller reading 'DO NOT USE ADDRESS 0!'
73082gibbers wrote: Mon Jan 24, 2022 11:55 pm ...was attempting to have it test ran on my local club's test track. Now this test track is DCC but can accommodate DC locos on it. On placing it on the track, it caused a short on the test track, so was moved onto a programming track, and it turned outthe that it was the loco at fault...
I wouldn't test anything on a club track unless I was very sure of the wiring and supply integrity, and know how of the club member(s) operating it. Putting a DC loco on test on a DCC programming track suggests a serious deficiency in understanding. That will immediately generate a 'fault' reading, as with no decoder present the test signal is shorted. So your model is fine, as the subsequent DC running proved.
Cheers for the response! I haven't actually chipped it because of what I thought was an issue, however I'll get a 21pin and fit it in, and see what happens. What's the preferred decoder for it, as I've used the Dapol Imperium one, and that works well in my class 73, so may roll with one of those for this.

Cheers,

Nathan
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Hatfield Shed
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Re: Oxford Rail J27

Post by Hatfield Shed »

Mine has the Zimo MX638 in it. If you are happy with a decoder brand, stick with it, only needing to read one decoder manual is a positive in my view!
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Re: Oxford Rail J27

Post by 73082gibbers »

Hatfield Shed wrote: Thu Jan 27, 2022 11:29 am Mine has the Zimo MX638 in it. If you are happy with a decoder brand, stick with it, only needing to read one decoder manual is a positive in my view!
Ended up fitting it with an Imperium decoder tonight, and thankfully it works well! Cheers for the help fellas!

Nathan
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nzpaul
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Re: Oxford Rail J27

Post by nzpaul »

Hatfield Shed wrote: Thu Jan 27, 2022 11:29 am Mine has the Zimo MX638 in it. If you are happy with a decoder brand, stick with it, only needing to read one decoder manual is a positive in my view!
As someone who has done exactly the opposite I can confirm this as being good advice. I have used all kinds of different decoders from Laisedcc, Gaugemaster, Hattons, Dcc concepts, NCE, Marklin, Uhlenbrock and TAMS. All do the job but the last two have some quirks in them. Dcc systems are worse, I've helped people get their heads around various devices from Lenz, MRC, and recently met one of the new Digitrax DT602 units...head melt that was. At the risk of being laughed at, I really like my Hornby Elite, it's user interface is friendly by comparison to most.

Glad you've had a good result with the J27 by the way.

Paul
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Re: Oxford Rail J27

Post by Atlantic 3279 »

What were we told about DCC being so easy? Just connect two wires to any part of the track and away you go...

They forgot the words "several hundred/thousand pounds later and after much anguish".

I just turn the knob on my analogue controllers and my locos go, as smoothly as could be desired, without any need for me to read any manuals and learn to custom programme each loco or to work out the relevance of multiple buttons and messages on the controller. Wiring up cheaply in sections and remembering which sections to switch on for which route and for which controller, via the comfortingly traditional and "signal box style" track diagram, has never been a mental challenge. I feel no need for artificial sounds or twinkly lights (nor for pulses of non-scale steam / smoke), and I don't feel psychologicaly deprived when I have no "digital comfort gadget" in my hand. Enjoyment lies in use of the imagination, one of many abilities I fear that many in younger generations have never been encouraged to develop.
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jwealleans
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Re: Oxford Rail J27

Post by jwealleans »

I feel no need for artificial sounds or ... pulses of ... smoke),
Au contraire, I'm a big fan of sound and smoke.
triang-hornby-r258-princess-elizabeth_360_9ba58aa9c90fd90b9861e83858633c60.jpg
mick b
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Re: Oxford Rail J27

Post by mick b »

:D :D
mr B
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Re: Oxford Rail J27

Post by mr B »

jwealleans wrote: Sat Feb 05, 2022 2:14 pm
I feel no need for artificial sounds or ... pulses of ... smoke),
Au contraire, I'm a big fan of sound and smoke.

triang-hornby-r258-princess-elizabeth_360_9ba58aa9c90fd90b9861e83858633c60.jpg

great stuff , I got new sandpaper for my B12 sound system from Peters spares :mrgreen:
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nzpaul
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Re: Oxford Rail J27

Post by nzpaul »

Atlantic 3279 wrote: Sat Feb 05, 2022 10:02 am What were we told about DCC being so easy? Just connect two wires to any part of the track and away you go...

They forgot the words "several hundred/thousand pounds later and after much anguish".
It's a ruse Graeme. While it's true that all the power and data is carried on a 2 wire bus, those 2 wires need to be run around the whole layout and droppers to the track installed at 2 metre (ish) intervals, just like a dc layout. If using dcc for points, independent power supplies need to be used for things to operate properly. Ultimately there will be less wiring but not by as much as they want you to think.
For use on the WMRES layout and eventually mine, which both have significant hilly bits, load control is the most obvious advantage, the decoder maintaining constant train speed going up or down hill. The bells and whistles and " realistic chuff chuff sound" I very rarely bother with unless demonstrating features to a curious observer, and I've only got a couple of locos with such features fitted anyway.
While I haven't seen your layout in its entirety, from what's viewable on youtube, I'm guessing it's similar in concept to Grantham or LB. I'm not sure dcc offers any advantage to a layout where locos/ trains are stored on isolated roads and run to a sequence or timetable and switched in or out when required. It really comes into it's own when multiple trains need to move independently on the same piece of track, engine shed layouts are perhaps the best example.

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Re: Oxford Rail J27

Post by Hatfield Shed »

Atlantic 3279 wrote: Sat Feb 05, 2022 10:02 am What were we told about DCC being so easy? Just connect two wires to any part of the track and away you go...
On my previous layout, a conventional 3 cab common return switched section DC set up, it literally was just 2 wires from the DCC system to cab 3 input, replacing the two wires from the DC controller, and set all sections to cab 3 for all DCC control, or as before switch sections as required to cabs 1 or 2 if wanting simultaneous DC and DCC operation. A layout wired to a good standard will take DCC 'just like that'. (I have maintained the switched section capability on my new layout for this convenience of operating a DC loco 'anywhere'.)
Atlantic 3279 wrote: Sat Feb 05, 2022 10:02 am ...They forgot the words "several hundred/thousand pounds later and after much anguish"...
About £2K, and I would make the same decision tomorrow for the control benefits, zero anguish.
Atlantic 3279 wrote: Sat Feb 05, 2022 10:02 am ... without any need for me to read any manuals and learn to custom programme each loco or to work out the relevance of multiple buttons and messages on the controller...
Different strokes for different folks. I researched what was on offer at time of purchase of the DCC system, and found one manufacturer with a well written and comprehensive manual*. This was always a solid guide to competence in determining which equipment to purchase on behalf of my employers, and came good again!
*Much like the documentation of one of my long ago preferred industrial equipment controller suppliers, something of a nostalgic experience!
Atlantic 3279 wrote: Sat Feb 05, 2022 10:02 am ...I just turn the knob on my analogue controllers and my locos go, as smoothly as could be desired...
I just push the buttons on my DCC handset and my locos go, as smoothly as could be desired.

It is the control refinement available that is such an asset of DCC, and - back on subject! - this advantage played well on the J27 I bought. The response of the motor was markedly non-linear, but a few settings on the decoder quickly sorted that for a smooth speed curve; maximum speed was limited to scale for 40mph and suitable values for inertia were entered so that the old girl takes time to slowly graft up to speed with a load on, and likewise takes time with its limited brake force to stop an unbraked train; this is a regrettably underused aspect of DCC, at exhibitions I still see 500 ton unbraked trains brought to rest from 25mph in a distance scaling 50 yards, the guard like a skittle if he wasn't hanging on. (I don't actually 'drive'; the DCC system does that, but watch the trains run from the lineside, just as I did when young, and the simulation of the high inertia of railway vehicles is so satisfactory. The sounds are played in my head - inaccurately in the case of a J27 - because the 0-6-0's I saw most of were J6 'knick-knacks' and that's what I want to hear when a pre-group 0-6-0 goes by...)
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Re: Oxford Rail J27

Post by Atlantic 3279 »

I fully take the point that a layout that has been built in a thoughtful way and wired in an exemplary mannnner for analogue DC operation can be run on DCC by simple substitution of the main two supply wires. What I have in mind is that such simplicity is not quite the same thing as suggesting that only two wires are required by somebody who perhaps doesn't understand electricity, who has possibly built a lyout without regard for the way it might need to be wired, and who can't / won't install a traditional sectional switched wiring set up.

If some are happy to spend a lot of money on digital control to compensate for poor motors and mechanisms, it is of course their right to do so. I'd prefer the motor and mechanism to be right in the first place, and if not, then changing the motor or the gears might be a cheaper solution.
Most subjects, models and techniques covered in this thread are now listed in various categories on page1

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Re: Oxford Rail J27

Post by mick b »

J27 with a remake over done a while ago.

Dave Bradwell Brass Chimney and Safety Valve improves the look. Cab Interior painted dirty Red. Smokebox rivets removed.
IMG_9811.jpeg
I now have also accquired a OXFORD J27 BR version , this has been stripped and a lot more work done theron back to LNER as a J26 , no chance of Oxford ever doing one. Photos soon.
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Re: Oxford Rail J27

Post by mick b »

Oxford J26 and Crane updates.
oxford j26.jpg
According to the Dark Side one of the Crane versions will be in Midland livery , I presume in Red with a matching Match Truck.
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