Increase loco speed in a TTS decoder

[JOHN-784683]

Could anyone advise me how I can increase the maximum speed in a TTS decoder. The maximum speed CV that usually exists in other decoders is not available in the TTS decoders I have. Thanks

[Fishmanoz]

You are correct, there is no Vmax setting CV enabled in any Hornby decoders, TTS or otherwise. Then in decoders where it is adjustable, the default is maximum anyway so, unless it has been adjusted down previously, you won’t be able to increase it.

For a start, can you try resetting your decoder (write 8 to CV8) and your controller (according to instructions in the manual for it). Has this made any difference?

The reason for the controller reset is to ensure it is on default 128 speed steps and not inadvertently on 28.

Also, after the resetting, is it only crawling around or running at a reasonable speed but not as high as you’d like? This will tell us if there is possibly a decoder fault needing return to Hornby.

[96RAF]

It would be useful to know which model it is as some models are geared down to more realistic speeds. I have a DMU which flat out seems tardy but is likely fairly true to prototype.

[ColinB]

I must admit on some DCC decoders I have noticed the top speed seems to have been throttled, but TTS decoders were not one of them. They are very susceptible to dirty track but never an issue with top speed.

[JOHN-784683]

Thanks for the replies.

The decoded in question is Lord Nelson class TTS.

Vmax is not bad but it could be a bit faster, I feel. I'm quite surprised that adjusting the speed on this type of decoder is so problematic. Leads to me to believe that you get what you pay for. Is that a fair assessment?

PS The loco came with the decoder pre-installed and the only change I have made is to change the address. It is set to 128 speed steps.

[96RAF]

Not a fair assessment at all.

The default and non adjustable (TTS and R8249 basic decoders) V-max as stated is value 255 equating to speed step 128. You cannot make it go faster. The design of a particular decoder H-bridge motor drive components determines the exact voltage seen by the motor at those default values.

Try a different (non Hornby) 8-pin decoder for comparison, just unplug the existing decoder and plug in the new one making sure you insulate against shorts.

[SteveM6]

Why the fascination with speed? They are not racing cars.

[JOHN-784683]

Why the fascination with speed? They are not racing cars.

 

 

Very helpful.

 

 

[SteveM6]

Why the fascination with speed? They are not racing cars.

Very helpful.

 

 

You’re welcome.

 

 

The point is that these are models that represent the real world in miniature. Full size locos are not particularly fast and rarely, if ever, travel ‘flat out’. Models are designed to replicate those traits.

In reality, a model loco would rarely need to be driven at more than half speed on the controller to simulate their full size performance.

[JOHN-784683]

Why the fascination with speed? They are not racing cars.

Very helpful.

You’re welcome.

The point is that these are models that represent the real world in miniature. Full size locos are not particularly fast and rarely, if ever, travel ‘flat out’. Models are designed to replicate those traits.

In reality, a model loco would rarely need to be driven at more than half speed on the controller to simulate their full size performance.

 

 

My loco, my track, my electricity - I can do what I like can't I?

[SteveM6]

I’m sure you will.

[96RAF]

Play nice you two.

Although not in the current published rules we still moderate to the old rules of being polite to each other.

[Brew Man]

However difficult that sometimes is.