DCC converted train has sound but moves only briefly before needing to be power cycled

[96RAF]

Here we go again…

it doesn't really give much more than TTS, the sound is a bit better but still no synchronization of chuff rate.

Nothing much more at all just …

By adjusting the complex speed curve values the chuff synch can be better matched.

Addition features TXS has over TTS

User updatable firmware for basic decoder and sound profiles

1 amp motor current - TTS is 0.5 amp

Plays 3 concurrent sounds in high fidelity - TTS only 2

Variety of decoder pin configurations - TTS is 8-pin only

Supports ADCC/ABC

Support for atomising steam unit and reluctor disk chuff synchronisation

Auto-calibration and full PID tuning for motor

Has de-coupling creep mode, shunting mode, auto-function play, dynamic brake, configurable lights for functions and brightness,

Plug in speaker and power bank (stay alive)

As many as 6 hardware functions.

etc etc - read the manual for more info.

[ColinB]

Yes 96RAF I hear what you are saying. It all depends what you want it for. For the 21 pin variety the powerbank connector stops the decoder sitting properly. As I said in previous posts I am tending to buy Zimo or Loksound decoders, when my Black 5 arrives it will be DCC sound fitted so again Hornby will have sorted all that out. I have used it, it is still fitted in my Queen Elizabeth West Country it is OK but not earth shattering. It is my opinion that is all, I don't know why you get so upset. I hardwire all my speakers the 21 pin socket, even the Hornby ones have dedicated solder pads to make it easier, so why do you need a plug and socket.

[96RAF]

Do what Jenny Kirk did then prise the sockets off to make the board slimmer, albeit binning the warranty as she stated in her video.

[ColinB]

I haven't watched that video but why would you do that? I am amazed she didn't damage the PCB at the same time, it is difficult enough getting surface mount items off when you do it properly. Have Hornby any plans to relocate it to the upper side like on the 8 pin variant.

[96RAF]

She did it to check the modified board would go into the loco smoke box attached to a factory fitted daughter board complete with speaker and end connectors that mate with the loco fixed wiring.

Not sure where Hornby could find space on the other side of the 21-pin decoder to relocate the socket without a total redesign.

[Paul-365510]

further update.

Got a response from Hornby support on the decoder going AWOL on BT. I worked through some suggestions but nothing helped. Then some decoder harnesses arrived so I followed previous advice, put one into the FS that was the subject of the original issue, and then swapped the naughty HM7000 to that and added a stay-alive. It's all working great now - Bluetooth, sound and all.

Doesn't explain why it was unhappy in the Mallard (but I've ordered a Loksound for that one now) but it does demonstrate again that the HM7000's can be badly behaved without a stay-alive.

Also I asked in my support request about whether the HM7000s needed wrapped in insulating tape and the answer was "yes, but leave some uncovered so it can breathe". A somewhat ambiguous answer, but what I'm doing now is wrapping them, installing them with a blob of hot glue, and then cutting away the tape from most of the exposed top.

I have another issue, should I open a seperate thread for it? I've noticed that the FS tender rocks as it goes over points - the wheels don't seem entirely happy with the frogs. Seems odd given it's a Hornby train on a Hornby point, but I can't be the only one who has noticed it. It's only the tender, not the loco or the carriages.

[96RAF]

The update pending across all profiles fixes this AWOL thing. If a loco loses track power, once it is restored the loco will carry on as before. If a power bank is fitted and has ran to empty say from a derail, it will take a good few seconds for it to recharge before the loco plods on again.

Ref insulating tape. It is better to insulate metal parts in the loco and allow the decoder to breathe. If it has to be wrapped then a bit of heat shrink sleeve with the ends warmed to grip the decoder is ideal or a single piece of Kapton tape over the decoder as it doesn’t leave a sticky goo and transfers heat.

[Fishmanoz]

Have you checked FS tender wheels back-to-back?

[SteveM6]

As Daedalus says the 21 pin version should not need any extra insulation as the plug holds it clear of other components - the same applies to Next 18.

However, the 8 pin is a different matter as it floats free on its wiring harness.

I routinely use a very thin, clear heat shrink on both TXS and TTS decoders and have not experienced any issues.......so far.

The vast majority of my non-sound decoders utilise direct plug in decoders from Hatton’s which are supplied already wrapped in a thin heatshrink and I have tally just followed their example.

[Paul-365510]

This is cut and paste from the Hornby guys response:

"The decoders need to be covered in electrical insulation tape, however they will need some space to breath so do not cover them fully."

I had just assumed that since the (8 pin) LaisDcc and Loksound decoders come in a plastic sleeve, there could only be some benefit in likewise covering the HM7000s.

I shall check the FS tender wheels back-to-back. Once I've looked up what that is :) Thanks.

[ColinB]

Hornby decoders have always seemed to have an issue with heat dissipation. I couldn't understand why I used to have random failures of TTS decoders then I realised it was because I heat shrinked them as per all the other decoders I buy with it already done. The 21 pin options are not shrink wrapped, as the mounting on a PCB is tons better than 8 pin and virtually impossible for it to touch anything metallic. For the 8 pin there is still a risk, so I fit them in a sleeve of unshrunk heatshrink so that the air can pass over them.

[Brew Man]

I just use a single layer of Kapton tape.

[Paul-365510]

I checked the back-to-back distance of the wheels on the tender (with calipers) and they are the same as the loco, carriages.

Getting out my glasses and pushing the tender slowly over a set of points on a bench at eye level I can see that the issue is that the flange of the front and rear wheels on the tender is deeper than on the loco and when it hits the frog it is rising up slightly because the groove in the frog isn't quite deep enough for the flange.

So I could (a) get out my dremel and deepen the slots on every point..., I think not, or (b) grind the flanges down slightly on the driving wheels of the tender which feels a little brutal and there's no way back from there.

Or © do nothing and just let it wobble as it goes through the points.

Advice welcome. This can't be the only time that this issue has been observed.

[Going Spare]

If still original, the flanges on the tender wheels are unlikely to be deeper than those on the engine. One wheel on the first and third axles of the tender should have a traction tyre fitted in a groove in the tread. If the tender wobbles, and assuming the wheels are running true on their axles, are traction tyres fitted? If so, are they twisted in the groove and are they the correct one for the loco: they should be a tight fit, fill the full width of the groove and not project above the level of the metal tread of the wheel. If they are loose or their surface has a glazed appearance, they should be replaced. If the loco was made in China, replacement tyres are sold in pack X8439.

[96RAF]

If you download the latest version of the sound for your locos that will fix the stalling problem.

[Paul-365510]

I will try that, thanks 96RAF.

[Paul-365510]

thanks Going Spare but there are no traction tyres on the tender.

the wheels on the tender have a small but noticeably deeper flange than the wheels on the loco. The second and last pair of wheels float but the first and third pair are the fixed driving wheels and when viewed from the side it's quite easy to see the wheel hitting the insulated part of the frog lifting very slightly and rocking the tender as it does so.

but it's an old FS (15+ years) running on new points, so maybe there have been some subtle changes?

It's only the wheels hitting the frog that lift, the channel in the outer guides is the full depth of the rail and causes no problems.

[LTSR_NSE]

@Paul - no traction tyres (on a tender drive loco) means they are missing! The apparently deeper flange (with an odd shallower flange on the outside of the wheel) is actually the channel to contain the traction tyres. If the tyres were present that would raise the wheels (& flanges) away from the points - as well as increasing the locomotive’s traction.

[Paul-365510]

oh wow. thanks. I was given the train by a friend whose son wasn't interested, it never had the traction tyres (dunno why) but I can see where they would go.

You've saved me from mutilating a train (or a 15+ points).

I've ordered pack.

thanks again.

[Paul-365510]

Hi 96RAF,

reloading the sound profiles does indeed seem to have sorted out the hiccups with the HM7000. Does this mean that Hornby found the issue and fixed it?

I would be relieved to know that this issue was nothing to do with my inexperience with decoders. Also delighted to have the same low speed control that I was seeing with the LaisDCC but with sound!

Perhaps I didn't need to fork out so much money on the Loksound decoder for my Mallard, which was DoA in any case, and I'm awaiting a replacement from the vendor. But it will be good to have experience with 3 different decoder brands.

Thanks everyone for the help with this.

Cheers.

[Fishmanoz]

Paul, yes one of the upgrades in the V2 sound profiles was to fix this issue.

It’s reported in various posts and a sticky with appropriate name.

Glad it’s solved for you.

[Paul-365510]

fitted the traction tyres (fiddly) but it totally solves the rocking problem.

I think that's the end of this thread. all my current problems are solved.

thank you all for the patient advice.