Flying Scotsman TTS jerky motion at crawling speeds

[Landyern]

This is probably in here somewhere but I can't find it

[Fishmanoz]

It is, multiple times and recently.  Start by changing CV150 from default zero to 1 (Write 1 to it).

[96RAF]

Here one with almost exactly the same title - found by searching on ‘jerky’ alone

 

https://www.hornby.com/uk-en/forum/flying-scotsman-tts-sound-jerky-start/

[Chrissaf]

.....but I can't find it.

 

For the future.... the Hornby forum search function is dire, but does work best if you search for single words and not phrases. The search engine is incapable of finding near hits, only 100% exact matches. The secret is to think of a suitable single word that the thread you are looking for might contain which is not always easy.

 

Read TIP10 in my TIPs page which describes how to use Google's Advanced Search Engine to search only the Hornby forum and no other Internet site. I use this documented technique a lot to locate those long distant forum posts lost in time.

 

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

 

However, in this case use "jerky" as the single word search term without the " " marks in the "Search Forum" box and you get about 10 hits where the word "jerky" appears in the topic title, some of which also have TTS in the title as well [see screen capture below], using the 'search post contents' option returns over 250 hits.

 

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As Fishy says, changing CV150 usually fixes this issue. But you do need a controller capable of changing CVs to do it.

 

EDIT: Rob just beat me to the post. His posted link is the second one up from the bottom in the topic title search results.

 

[Landyern]

Thanks for the replies, however changing cv150 to 1 is far better but it still seems to strain as if not getting enough electricity and the jerking forward  every so often and is the same in reverse. 

Thanks 

[96RAF]

You now need to fiddle with CVs 153/4 which refine the motor algorithm.

If you had left CV 150 set at value zero then you would fiddle with CVs 151/2.

There is another thread on here which explains to some extent the ‘science’ and methodolgoy behind these further P&I adjustments.

Probably one of those in that search list.

[Mac-_-]

I asumme every thing is clean.

[Landyern]

Hi, yes everything is nicely clean, I have it working smooth and crawling smooth however it's strange because when I first switch on it is jerky again but after say a loop or maybe two everything settles down and she's smooth again. 

Thanks for all the help

[creilly81]

Not wishing to say the obvious, but have you checked the valve/motion gear to see if there is anything bent or catching?

[96RAF]

If it works fine after warming up then maybe the loco needs a clean and lube. Some motors do run better when warm, which is why RM suggests running a loco for a few laps before calibrating its speed. A bit like an old car really, not running smoothly until you got the choke fully in a couple of miles down the road.

[Mac-_-]

Sounds abit like my self in the mornings Redesdale :(. Out of curiosity where abouts do you have the layout. I know some of my old loco's don't like being first on the track in the uninsultated roof space, this time of year.