Hornby Smoke and Sound Synchronisation

[Qweqwe]

Hi,

Hornby’s new smoke and sound steam engines appear to have said effects synchronised to the motion of the wheels. For example the smoke and sound Hornby P2 seems to consistently chuff 6 times per wheel rotation, unlike other sound fitted models where the chuffs don’t seem to align exactly with wheel rotation. Perhaps it’s my imagination but the synchronisation seems far more accurate than what I’ve seen in other sound locos, correct me if I’m wrong.

In the Sam’s Trains’ review of the new Black 5 in the “mechanism” section, a little disc is visible, attached to one of the driving wheel axles. Is this disc used to accurately synchronise the sound and steam with the wheel rotation? Does anyone have any insight into how this system works?

 

Also, do any other  RTR sound fitted steam engines have a mechanical system to accurately synchronise the sound to wheel rotation?

[RAF96]

Short answer - yes it triggers the decoder to fire the sound and smoke at the right time.

A different disk will give different chuff patterns.

Most other systems use the decoder to set variation of chuff for matching.

[Qweqwe]

Thanks for the reply, that seems to be an awesome feature! Is it possible to install such a system to other locomotives? Or is this system exclusive to these specific Hornby locos?

 

I’m specifically interested in the synchronisation of the sound with the rotation of the wheels on a hardware level rather than just calibrating the decoder without mechanical means to set the timing.

 

Thanks!

[GrumpyPenguin]

2 hours ago, Qweqwe said:

Thanks for the reply, that seems to be an awesome feature! Is it possible to install such a system to other locomotives? Or is this system exclusive to these specific Hornby locos?

 

I’m specifically interested in the synchronisation of the sound with the rotation of the wheels on a hardware level rather than just calibrating the decoder without mechanical means to set the timing.

 

Thanks!

There is probably a little more work to syncronise sound/smoke using the decoder for reference - AFAIK the decoder "counts" the motor revolutions & works it out from there - accurate enough toi stop locomotives to with a mm when constant braking distance acticated.

The method Hornby use is probably more cost-effective for production models - not a new concept though - Fleischmann (& probably others) have used this type of sensors in their Tachowagons.

[No Decorum]

5 hours ago, Qweqwe said:

Thanks for the reply, that seems to be an awesome feature! Is it possible to install such a system to other locomotives? Or is this system exclusive to these specific Hornby locos?

 

I’m specifically interested in the synchronisation of the sound with the rotation of the wheels on a hardware level rather than just calibrating the decoder without mechanical means to set the timing.

 

Thanks!

It’s a clever feature and Hornby is to be commended for doing it. I have no experience of it but I’m not going to let that stop me speculating. For one thing, it gets round the extraordinary sight of a model sounding as if it’s slipping when the wheels are obviously not slipping. It should also be a lot easier to match the turning of the wheels to the exhaust beats.

Fitting such a system to a locomotive without it is bound to be difficult. First of all, a slot would have to be machined into the chassis to take the perforated disc. Next, a sensor of some kind would have to be fitted in order to detect the slots in the disc. Making the disc itself is likely to be the easiet part – just drill holes in it carefully. Last, a decoder would need to be programmed to accept the input from the sensor and translate it into exhaust beats.

 

If the system were to be adopted more widely, I’d be interested but it would have to be designed into the model. I don’t think I would have a hope of installing it into an existing loco. I shall just have to continue to tinker with decoder settings to match the exhaust beats and the turning of the wheels.

[Fireline]

7 hours ago, No Decorum said:

I have no experience of it but I’m not going to let that stop me speculating.

 

Said in the finest traditions of forums everywhere. 🙂

[Qweqwe]

Thanks for the replies! This mechanism seems like such an interesting new thing to me and I was surprised I couldn’t find anyone else discussing it. I really believe the next generation of DCC sound decoders should include a timing sensor (if that’s what it’s called) so that it can be installed on other locos.

Just like how “dcc ready” analog locos these days come with lights, a dcc harness and space for a speaker, I’d say the next step would be for manufacturers to start adding that little disc to the driving axle of analog steam locos too. This way you could buy a “dcc sound ready” loco which would come with a dcc slot, the little disc on the driving wheel and a space for the speaker. Then you’d just go out and buy your sound decoder and speaker. Once installed you’d have perfectly synchronised sound, which in my opinion looks even better than the current motor/chip based synchronisation.

 

What do you all think? Do you see the synchronisation disc and sensor ever becoming a feature that can be bought separately and installed the same way we do with dcc chips and speakers today?

[No Decorum]

28 minutes ago, Qweqwe said:

Thanks for the replies! This mechanism seems like such an interesting new thing to me and I was surprised I couldn’t find anyone else discussing it. I really believe the next generation of DCC sound decoders should include a timing sensor (if that’s what it’s called) so that it can be installed on other locos.

Just like how “dcc ready” analog locos these days come with lights, a dcc harness and space for a speaker, I’d say the next step would be for manufacturers to start adding that little disc to the driving axle of analog steam locos too. This way you could buy a “dcc sound ready” loco which would come with a dcc slot, the little disc on the driving wheel and a space for the speaker. Then you’d just go out and buy your sound decoder and speaker. Once installed you’d have perfectly synchronised sound, which in my opinion looks even better than the current motor/chip based synchronisation.

 

What do you all think? Do you see the synchronisation disc and sensor ever becoming a feature that can be bought separately and installed the same way we do with dcc chips and speakers today?

I think I’ve been trying to say that installing the system on a pre-existing loco is impractical. However, if the system is designed into a loco from the start, it shouldn’t add much to the cost. That is, the slotted disc and the space for it in the chassis. What I don’t know is how much the sensor would add to the cost but, as speakers are often added to non-sound locos these days, perhaps it wouldn’t be a deal breaker. Alternatively, space for a sensor could be incorporated into the design and the sensor bought with the decoder as part of the upgrade to sound.

 

I know I make it appear simple. In practice it isn’t. Take Hornby’s Class 87 as an example. When first released, the decoder slot was too small for a standard decoder and there was no room for a speaker. The current revised 87 is better but still falls short on ease of linstallation. Hornby’s 71 was even worse. You can say what you like about the many shortcomings of DJ Models but Dave Jones did ensure that due space was available for a sound decoder and speaker.

 

In fairness to Hornby, other manufacturers can fall short in this respect as well.

[Qweqwe]

Yeah it is definitely an interesting thing to think about. I still find it very strange that some analog locos come with speakers installed. If I wanted to install dcc sound to an analog loco I’d rather have the disc pre installed than a speaker. Of course I’d still want a space for the speaker but the speaker itself is more of a personal choice and is easy to fit as long as an empty space is left. The disc on the other hand would be very difficult to install if the manufacturer doesn’t leave a slot for it in the chassis, but conversely would probably be quite an inexpensive part for the manufacturer to add compared to a speaker once the chassis has been designed with a space for the disc.

I’m still totally impressed by how satisfying it is to hear the “chuffs”  in time with the actual motion of the wheels/pistons. I honestly never considered dcc sound before because hearing the chuff happen at a different point in the wheel rotation each time was breaking the immersion for me. But with this disc mechanism I’m totally sold.

The only problem is this disc is only available on giant mainline steam locos, whereas I want it in something like a peckett or a pug haha. I guess I’ll have to wait…

[MikeParkin65]

9 minutes ago, Qweqwe said:

Yeah it is definitely an interesting thing to think about. I still find it very strange that some analog locos come with speakers installed. If I wanted to install dcc sound to an analog loco I’d rather have the disc pre installed than a speaker. Of course I’d still want a space for the speaker but the speaker itself is more of a personal choice and is easy to fit as long as an empty space is left. The disc on the other hand would be very difficult to install if the manufacturer doesn’t leave a slot for it in the chassis, but conversely would probably be quite an inexpensive part for the manufacturer to add compared to a speaker once the chassis has been designed with a space for the disc.

I’m still totally impressed by how satisfying it is to hear the “chuffs”  in time with the actual motion of the wheels/pistons. I honestly never considered dcc sound before because hearing the chuff happen at a different point in the wheel rotation each time was breaking the immersion for me. But with this disc mechanism I’m totally sold.

The only problem is this disc is only available on giant mainline steam locos, whereas I want it in something like a peckett or a pug haha. I guess I’ll have to wait…

Not sure Hornby are one of the manufacturers that pre fit speakers to DCC ready loco's so far. Hornby's disc is solving a problem specific to Hornby's approach to DCC sound. Other DCC sound manufacturers (mainly ESU, Zimo and D&H in the UK at the moment) all use a calculation within the chip to synch the chuff's to movement. On a well set up chip this is totally convincing and removes the need for any physical counter. That said I believe all of the manufacturers I mentioned have the option of adding a sensor to the wheel spokes of that is the modelers' preferred method. I think this is more common in the larger scales.

 

Hornby's TXS sound is an interesting development but I think unless they allow for the synched sound by the calculated route rather than requiring modification to the model its usefulness to the steam  modeler with an existing roster or wanting to fit loco's made by other manufacturers will be  limited.

[Grovenor]

Early sound decoders from Sountraxx had provision for a cam to synchronise the sound to the wheels. They supplied a selsction of cams suitable for 4 or 6 cylinders and different wheel diameters. I have one I fitted over 20 years ago. The synch works well although the decoder is relatively crude in other areas. The Cams supplied glued to the back of a driving wheel so could be retrofitted.

[Qweqwe]

1 hour ago, Grovenor said:

Early sound decoders from Sountraxx had provision for a cam to synchronise the sound to the wheels. They supplied a selsction of cams suitable for 4 or 6 cylinders and different wheel diameters. I have one I fitted over 20 years ago. The synch works well although the decoder is relatively crude in other areas. The Cams supplied glued to the back of a driving wheel so could be retrofitted.

Ah that’s so interesting, this is exactly the thing I’d interested in. If it’s been done before maybe it can be done again, especially with Hornby doing having it pre installed in their locos, maybe it’ll catch on.

I’d certainly be one of the first customers haha

[GrumpyPenguin]

14 hours ago, Qweqwe said:

What do you all think? Do you see the synchronisation disc and sensor ever becoming a feature that can be bought separately and installed the same way we do with dcc chips and speakers today?

Can be done via a decoder counting motor revolutions which would be easier to retrofit 0 no need to dismantle, upsetting fine valve gear & quartering.

 

For me, the biggist issue is not fitting the speaker in the smokebox - once your ears are attuned to the sound coming from the wrong end of the locomotive the effect is lost.,

[Qweqwe]

22 minutes ago, GrumpyPenguin said:

Can be done via a decoder counting motor revolutions which would be easier to retrofit 0 no need to dismantle, upsetting fine valve gear & quartering.

Yeah I’ve seen a few videos and it does seem to get pretty close, but I notice especially when accelerating and decelerating that the sound goes out of sync which definitely breaks the immersion for me.

That’s also an interesting point about the sound coming from the wrong end of the loco. I suppose that is something that YouTube videos aren’t able to portray!