Hornby Class 08 stopping

[m.levin]

Hi guys

Just wanting so ideas and things to try.
Hornby Class 08 just cuts out, completed all the following.
Tried a full strip down and service, checked pick ups all ok.
Thought motor, disconnected the drive and ran the motor without load, runs ok, put some pressure on the flywheel, to simulate a load and still ran ok.
Removed the con rods and ran with out, on a rolling road, started to cut out again.
Used my analogue power supply, with current display and warning and didn’t see any spikes of current ran about 100mA but did see the current drop, when it cut out.
Any ideas??

[centenary]

Hi guys

Just wanting so ideas and things to try.
Hornby Class 08 just cuts out, completed all the following.
Tried a full strip down and service, checked pick ups all ok.
Thought motor, disconnected the drive and ran the motor without load, runs ok, put some pressure on the flywheel, to simulate a load and still ran ok.
Removed the con rods and ran with out, on a rolling road, started to cut out again.
Used my analogue power supply, with current display and warning and didn’t see any spikes of current ran about 100mA but did see the current drop, when it cut out.
Any ideas??

Sounds like the motor issue Hornby had on a well known loco last year. If you can, replace the motor would be my guess.

[Dad-1]

Intermittent fault ?
Sounds like a continuity problem, a broken wire, or dry soldered
joint.
If the loose motor runs for some time with test wiring what else
is there ?

Geoff T

[Bigmet]

Certainly does suggest intermittent loss of continuity. If it only happens after some running time, but never when first started from cold; top suspect are locations where the circuit is warmed by operation, which in our models is the motor. Contact of brush spring to terminal or carbon is a possibility which unfortunately is within a 'sealed unit'; so I wouldn't go there until absolutely certain this is the location, because repair can be difficult.

[m.levin]

I thought maybe a dry solder joint, so replaced the wiring from pick ups to decoder and re soldered decoder to motor. But no change.
Next step is motor replacement.
Ruled out decoder as I bypassed this and still had the same issues.
It’s one of those, try everything before shelling out for a new motor, knowing deep down its a motor, but each try living in hope!
It will have to sit on the work bench for another few weeks, as I need to finish off work on other locos.

[Mountain]

In a case like this, try removing the motor and place a 12v bulb instead and push the chassis round the layout to see if the bulb goes off. (A small flickering is normal... As long as it does not show signs of going off. I would test on DC).
push the chassis from behind via another item of unpowered rolling stock or try pulling via the couplings using an unpowered item of stock.
If all seems ok (Ensure that the chassis has its weight while testing), then it is only the motor that is left...

[Metadyneman]

My suggestion is that you have a decoder fitted which does not tolerate what is known as "brown outs". These occur when the current is momentarily interrupted by either dirt on the track, moving over dead frogs on points or the pick ups momentarily parting company with the wheel backs. Locos with short wheel bases (such as the 08) are particularly prone to this and whilst they will be fine on DC, on DCC a sensitive decoder will see it as a cut in power and re set itself. There are two potential suggestions I can offer you for this problem. The first is to fit a decoder which is tolerant of "brown outs" . DCC concepts now make all their decoders with "brown out" protection and Rails of Sheffield decoders also have this facility on their connect decoders (they are engineered by DCC concepts). Bachmann & ESU are ok to a point but again with short wheelbases they are less tolerant. Lenz are also ok. Incidentally, early Hornby, Laisdcc, Hattons, Gaugemaster and Dapol imperiums don't like "brown outs" and are thus probably not suitable for a Hornby 0-6-0 loco.
My second suggestion is to fit a small "stay alive" capacitor to the decoder which ensures there is a short electrical continuity to the decoder when the pick ups momentarily fail to pick anything up! I appreciate there is not a lot of room in a Class 08 to do this but I believe Richard Croft at https://www.roads-and-rails.co.uk/ offers a service to fit them.
I hope this helps
Jules (of garden railway fame )

[Mountain]

If it is as metadyneman said, a way around this is to set the decoder values for the inertia and the back EMF to zero, or to the lowest figure. This will turn off the decoders inertia and back EMF and allow the loco to run as if it were a normal DC loco. (What I mean by this is on DC, if the loco runs over a dead frog point (Or somewhere else where it loses current), it will use its momentum until it reaches current again to continue, but with DCC the decoder senses there is no current and will think it has to start the inertia again as if the loco was stationary and do a dead stop to start the inertia process again. Stay alive decoders prevent this by internally providing current for a short time to allow the decoder to pass over the short section of dead track, but unfortunately they are expensive, though the really simple solution is to just go into the settings and switch off the features listed above).

[m.levin]

Hi

I removed the decoder tried it on DC monitoring the current and saw a drop in current, not a spike. so ruled out the decoder.
But I have made some progress, I purchased some new coupling rods from Brassmasters, as the old ones had a little bit of play in them. I did try to run it without the coupling rods and still had an issue. Last night I made up the coupling rods and tested them this afternoon, I ran it without the parts that surround the worm drive and it ran like a new loco. I'm going to leave it to sit for a while, as I have Manflu and climbing up in to the loft was like climbing 50 flights of stairs!! Tomorrow I going to test it again as it is, if I get the same good results then I can start adding pars back on it, I will add 1 part at a time test it and see what happens.

My suggestion is that you have a decoder fitted which does not tolerate what is known as "brown outs". These occur when the current is momentarily interrupted by either dirt on the track, moving over dead frogs on points or the pick ups momentarily parting company with the wheel backs. Locos with short wheel bases (such as the 08) are particularly prone to this and whilst they will be fine on DC, on DCC a sensitive decoder will see it as a cut in power and re set itself. There are two potential suggestions I can offer you for this problem. The first is to fit a decoder which is tolerant of "brown outs" . DCC concepts now make all their decoders with "brown out" protection and Rails of Sheffield decoders also have this facility on their connect decoders (they are engineered by DCC concepts). Bachmann & ESU are ok to a point but again with short wheelbases they are less tolerant. Lenz are also ok. Incidentally, early Hornby, Laisdcc, Hattons, Gaugemaster and Dapol imperiums don't like "brown outs" and are thus probably not suitable for a Hornby 0-6-0 loco.
My second suggestion is to fit a small "stay alive" capacitor to the decoder which ensures there is a short electrical continuity to the decoder when the pick ups momentarily fail to pick anything up! I appreciate there is not a lot of room in a Class 08 to do this but I believe Richard Croft at https://www.roads-and-rails.co.uk/ offers a service to fit them.
I hope this helps

I have currently been testing the loco on a straight section of track, Every section, no matter how small, has droppers on them, I even cleaned the track and wheels, which something I avoid as I hate cleaning track. I tested it on a straight section with no points also my rolling road. I have also seen that its not been on the same bit of track, every time it stopped, also marked the wheels to see if its the same point that it cuts out, its very random. so this leads me to believe that its not the track/connection.

I plan to fit a stay alive in it at some point, but Ideally I want to ensure that its running well without one first. I have built my own points, so no worry about Isofrogs and tried to minimise the amount of points on the layout, as we all know how much fun points can be for derailing fun!!

[Mountain]

A thought. Is this a loco that came from a DCC trainset with another loco in the set (Think it was a Jinty?) Built to the older body design which had an unrealistic (Visually) chassis. These later versions of the earler design are known to give issues due to the poorly designed chassis. Versions built in the earlier years (E.g. pre-1990's) ran fine though were unrefined).
There is a newer super detailed version with intricate detail and a heafty price which I assumed you were talking about. These should run well though the very first few batches had screaming motors (Tried everything from oiling to packing with washers. It still screams!), but they should not have any pick up issues as these newer type (From around 2005 onwards I think) are designed better.
The older design but with the re-designed (Cheaper to produce) chassis were still sold in the Thomas range and as part of a budget DCC trainset.
Somewhere I have seen possible remedies where others had improved them, but the easiest improvement is to get an earlier X03/X04 motored version and hard wire a decoder into it. The old X03 or X04 motors (Shouod be an X04 in the old 08's unless one gets the even earlier different body style Triang versions which had X03 motors which look the same) were a little crude and noisy but they were hardy and reliable. Needed a powerful controller though to run the things!

I am wondering if your 08 is one of the budget versions with the more modern chassis that people found gave issues? Oddly the 08 seems to be the one giving issues whenthe similar chassied Jinty in the set seemed ok? (Maybe those who own them can comment).

[m.levin]

I believe it’s one of the earlier super detailed ones, it’s definitely not the one in the jinty set. You can see the 08 in my layout thread.
But when looking at motors, Hornby replaced the motor on newer ones.
I’m going to try it out today and start building it back up. Only thing left to replace now is the motor.

[Mountain]

Frustrating though to find onself having such issues. I kinda gave up on mine not long after buying it due to the screaming motor and there it has sat stored away to this day. Another new but has hardly turned a wheel in a similar position is my Hornby class 50. Oddly they are both newish designed super detailed locos and the only real two locos I have in my collection that have issues apart from a Lima 08 chassis (Which normally behave as I have more then one) that I need to fiddle with as it used to play up when I bought it secondhand. Fiddled with it and it ran really well for ages....Then "Disturbed" it after dissassembling the motor to make it fit into a narrow gauge loco and I have yet to fiddle with it again to make it run well. (Is a slight cog alignment which needs sorting so is waiting for me to spend time with it to get it to run well again).
But those two Hornby locos... Think I may get the 08 to run as it does run but annoyingly screams. The class 50 is the one I have really given up on. Poorly designed from a servicing point of view to be honest. Would have been better if Hornby had kept to Ringfield motors driven at one end because those were easy to service and repair. Somehow Bachmann seemed to get the central motor idea to run better and be more robust to service the things. Got a pair of class 46's (One has a Mainline class 45 body) and they are excellent runners and had no issues stripping them to hard wire decoders into them. And their 08 is reliable. Not quite as finely detailed as Hornby 08's, but I prefer them because they gave me no issues.
Though crude in appearance, the Hornby Dublo and Wrenn 08's are excellent underneath! The only one downside (Detail is good for its age) is a large quite visible screw on the top of the body to hold the body to the chassis. Apart from that they are very long lasting and a pair of these ran reliably for many years on a garden railway where apart from the owners Wrenn 8F 2-8-0 which also just kept going and going, every other manufactures loco he tried back then needed total rebuilding after a few years use just to remain in service. (He ran trains daily for a goodn12 years).

For me the biggest issue I have is that I have not run my locos for a fair few years, so they often need freeing up. They did run very well... Then stored away and then discover I need to coax them back into service.

[m.levin]

I got a new Digitrax sound decoder for this class 08, fitted it and noticed this issue. Thinking it was decoder had a play around with the CVs. I keep a log book for every loco and note issues. Went to log this issue and Under this class 08 was “wheels need a clean and loco needs service, cutting out” from back in 2019. One of those “I will look at that when I can be bothered” moments lol I’m great at logging things but not so looking at the log until I have issues.

[m.levin]

I have had a good result. Built the 08 back up and it’s running like a new loco.
I’m still not sure what’s fixed it, could have been a contribution of all the following.
Wheel and track clean,
Stripped down and oiled/greased,
Cleaned pickups,
Rewired from picks up to motor,
Replaced connecting rods, with Brassmaster connecting rods.
I did replace the decoder, but had the same issue on dc, decoded still set as factory, so I can now fine tune, install stay alive and lights. Then final task is paintwork and weathering.

Thanks for all the advice and suggestions.

[Mountain]

Glad all is running fine. Well done!