Hornby 0-4-0 Loco Speed

[BrumDave]

After reading another thread where the little Hornby 0-4-0 locos were likened to an F1 racing car I thought I would share my experiences with these little uns, I love small locos and have quite a few of them, I have my layout wired for DCC but run them as DC through electrofrog points, a top quality controller with a 4 amp power supply, none of mine race and all will creep away from a start and slow down at a realistic speed, when using Inertia I can watch these little locos pull a train at a super show speed without as much as a hicup, some of the well informed forum members may know for sure but I have a feeling Hornby may have changed the gearing or motor as they seem to perform as good as many other Hornby locos.

[GeoFF03]

They may have made a change around 2010, as the Collectors Club model from that year is the only one I have that has acceptable slow speed running and lower top speed.  The three previous club models will all try to throw themselves off the track when taking cruves before full speed is reached.  The three older models also have widely differing performance compaired with each other.

[96RAF]

I've been trying to find a service sheet for these newer models to see if the old 0-4-0 X8004 gear set has been changed as it would be handy if the new set would retro fit to older models.

[The Doc]

I'm not sure if they have changed the gearing, but the more recent models appear to have a resistor (as well as the usual capacitor) that presumably reduces the current flowing through the motor at any particular setting on your controller.  Another observation I have made is that the recent 0-4-0 models that have the diecast metal footplate are much better runners (class 06 diesel shunter, Caledonian saddle tank).  I suspect that the extra weight means that all four wheels remain in contact with the track, whereas with one of the very lightweight models, the moment it goes over slightly uneven track one or more wheels leaves the track, maybe only by a fraction of a millimetre so you can't see it, but enough to lose electrical contact.  The diescast footplate may also help to keep the cheap plastic chassis rigid.

If you want to get the best performance out of these 0-4-0s you should consider permanently wiring up a shunters truck with metal wheels + extra pick-ups.  It works nicely with my old GWR 0-4-0.

[81F]

I'm not sure if they have changed the gearing, but the more recent models appear to have a resistor (as well as the usual capacitor) that presumably reduces the current flowing through the motor at any particular setting on your controller.  Another observation I have made is that the recent 0-4-0 models that have the diecast metal footplate are much better runners (class 06 diesel shunter, Caledonian saddle tank).  I suspect that the extra weight means that all four wheels remain in contact with the track, whereas with one of the very lightweight models, the moment it goes over slightly uneven track one or more wheels leaves the track, maybe only by a fraction of a millimetre so you can't see it, but enough to lose electrical contact.  The diescast footplate may also help to keep the cheap plastic chassis rigid.

If you want to get the best performance out of these 0-4-0s you should consider permanently wiring up a shunters truck with metal wheels + extra pick-ups.  It works nicely with my old GWR 0-4-0.

 

Any idea what value the resistor might be?

[BrumDave]

Have to agree regarding the construction of the Saddle Tank and Class 06 the extra weight does make a difference, well done Hornby hope you do the same to the other 0-4-0 locos.

[Fishmanoz]

I think you'll find it is an inductor, not a resistor, and is just part of the suppression circuit.  I certainly can't remember seeing a resistor in these models.

[Wobblinwheel]

Is there a way to put a resistor (or similar) in these "too fast" locos to slow them down? My little Dapol N gauge 0-4-4 can hardly be controlled at very slow speeds as the motor "takes off" at about one volt of DC power! Would a resistor do the job without getting too hot?

[BrumDave]

I think maybe a Diode is required rather than a Resistor.

Basic Electronics

http://www.nerdkits.com/forum/thread/2659/

[GWR LNER fan 4472]

 I have four Hornby 0-4-0 locos: a 1970s GWR 101, the Rothery Industries 101 class no 391, 'Percy' from about 2008 and BR class 06 no 06008. They're all DCC apart from the 70s 101 which when I run it on an analogue layout it can go like a Scalextric car! The Percy was bought for the kids to use on our family layout and they ran it so fast we think the motor burnt out as it doesn't move and smells smokey (and don't say it's because it's a steam engine 😛). The other two run at a more realistic speed for these small locos, I think this is because they're newer and Hornby might've as you say changed the gearing or whatever.

[Chrissaf]

I think maybe a Diode is required rather than a Resistor.

Basic Electronics

http://www.nerdkits.com/forum/thread/2659/

.

A silicon diode will introduce a voltage drop of about 0.6 volts with virtually no heat being generated. However, a diode only passes current in one direction so if you put a diode in series with the motor for going forward, you will not have any movement of the loco going backwards, because the diode will block the current flow.

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I suppose you could get round this by putting two silicon diodes in parallel, but each the opposite way round to the other. Then one of them will be forward biased with the 0.6 volt drop, whilst the other is effectively infinite resistance because it it is reversed biased. Then when you put the loco in reverse, the biasing of the diodes is reversed too.

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The unanswered question is - will a 0.6 volt drop make any difference to the speed control issue..........I can only suggest try it and see. If I was a betting man, I think maybe not.

.

If it goes off like a rocket at 1 volt, then that is no difference to it going off like a rocket at 1.6 volts. The diodes are not going to limit the current, just affect the voltage needed to trigger that going off like a rocket current.

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With a resistor on the other hand, as the current passing through it increases, the voltage drop across it introduced by that current flow increases proportionally. Thus a resistor gives an element of dynamic voltage control to the motor, that a diode is unlikely to do. But then, heat (watts) comes into the equation, using a resistor. A resistor will get heated up.

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The generic readily available 1N4001 diode is silicon and rated at 1 amp.

[Fishmanoz]

Then put a few geraniums in the tender, half of them upside down, and see if that does the trick?

[Postman Prat]

Hi Fishy

 

Are you suppling the upside down Geraniums?

[96RAF]

Service sheets for the latest little monsters would be a simpler idea - anyone found them yet, apart from Sentinal and Bill/Ben which appear to have a different setup with an intermediate gear.

 

There was a similar mod someone did on another forum a long time ago by building a plasticard gearbox case, introducing the intermediate gear and making the motor horizontal as opposed to angled.

[Chrissaf]

Then put a few geraniums in the tender, half of them upside down, and see if that does the trick?

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It's OK Fishy....I understood the joke (for once), even if it did go over the head of others.

[Johnde]

 Simple answer is GO DCC and use a decoder that enables you to reduce the Max voltage ( i forget the CV of hand ).

Have done just that and I have an 06 that can crawl along instead of starting up and running like a  headless chicken.

[Fishmanoz]

Got it in one PP.

 

And of course you did Chris.

[Chrissaf]

Germainium of course, not Geranium is the answer....

[BrumDave]

I originally posted this because a post by someone likened the 0-4-0 locos to an F1 racing car, I have never found that to be the case which is most likely due to the equipment I am using to run them, top quality controller, 4 amp power supply, electrofrog points, bus wire and droppers every couple of feet, it seems that these little engines still run to quick for some people so I guess that explains all the debate about ways to slow them down, I can get these locos to start off and stop in a realistic way without going DCC, however I will eventually go DCC again on my layout for other reasons.

[Fishmanoz]

Sure you don't mean Greerium Chris?  She seems to have been growing her flowers upside down lately too.