DCC Chip settings help

[Weardale Wanderer]

Hello all,

 

Can someone help me with a connundrum?

 

I've been building a model 507 and have fitted a Hornby X9882 Class 153 DMU Drive Unit into it. I've got an ESU V5 sound chip in there with an ESU stay alive.

 

Starting from halt, the motor is horribly jerky until it gets moving. Similarly, when it's coming to a halt the same happens when coming to a low speed.

 

I tried turning off Back EMF and it's very smooth, however it takes ages to get going, slows down on slight gradients, picks up speed at various points, and is completely out of synch with the motor sound.

 

Therefore it seems Back EMF is the way to go, but what on earth do I do with the settings to make it a smooth start and stop? I have the ESU programmer, but I haven't got a clue what I'm looking at. Complicated doesn't begin to describe it!

 

Can anyone help?

 

Cheers,

Mark

 

 

[BoD]

Did you get a chance to check it’s running on DC before fitting the decoder?  If so was it able to run smoothly over the full range?

 

Loksound has an auto tune facility which in some cases can solve the problem you are experiencing.  See here for details https://dccwiki.com/LokSound_Auto_Tune

 

You can ignore the technical stuff and go straight to the how to do it section. The important bit is to leave space for the loco to run for about 1m as you do it.

[Weardale Wanderer]

Thanks for the above. I've tried the CV54 'auto tune' feature this afternoon. The model certainly runs a lot smoother, except that now the sound switches off just after starting off, and comes back on as it's coming to a halt.

 

A google of this issue appears to suggest the sound file can't 'link' somehow with the new CV54 setting (which is flagging up as a value of 12).

As it stands, If I want to have sound I'll have to reset the file back to what it was before (Jerks and all). 

 

Considering how many options there are with the ESU chips, there must be some setting I can fiddle about with to get the motor running smoothly and keep the sound.

 

Any suggestions welcome. :)

 

[BoD]

9 minutes ago, Weardale Wanderer said:

Thanks for the above. I've tried the CV54 'auto tune' feature this afternoon. The model certainly runs a lot smoother, except that now the sound switches off just after starting off, and comes back on as it's coming to a halt.

I haven’t come across that before with any of the sound projects where I have used the autotune feature. Seems strange.

Apologies for causing you a further issue.

[Weardale Wanderer]

You haven't caused me an issue at all. To the contrary, I think knowing about CV54 will be extremely useful for my other locos.

 

I don't what the problem is with this one, but I can live with it. It's been a headache since day one in any case!

 

I'm just grateful for you using your time to offer a newbie like me some much needed (And welcome) help and advice. :)

[34theletterbetweenB&D]

My experience of ESU decoders is limited and dated, but those I used had a pair of CV's to optimise the sampling and feedback of the BEMF regime, and this :

On 12/11/2023 at 11:05, Weardale Wanderer said:

Starting from halt, the motor is horribly jerky until it gets moving. Similarly, when it's coming to a halt the same happens when coming to a low speed.

is a good description of  what these adjustments enabled me to overcome, es[pecially on smaller three pole motor mechanisms. Starting from both CV's  with mid-point values vary one significantly higher and the other significantly lower, then the other way around, with each change checking for performance improvement, and from the best pair of settings then iterate toward the optimum combination. I expect that's pretty much what the 'auto tune' feature is programmed to do.

 

(Of course no idea if these CV's are still accessible, nor whether the sound will integrate properly if they are available and you find they have good effect.)