Non Hornby Loco's speed settings

[Cowplain]

I am sorry if I am raising an old subject, but I have tried several key words/phrases search to try and identify a thread regarding the subject.

Out of the 7 loco's I currently have all are Hornby, except for one which was given to me as a present from a family member. The one that is not Hornby is a Blue Box 0-6-0 tank GWR 5766.

I have full control of this Loco under RM and Elite, but it Hurtles along at aprox double speed set on RM. It is fitted with a Blue Box 24 Pin Blue Box Decoder and travels at least twice the speed of the RM settings and demands! I do not have the luxury of being able to use a test track as defined in the RM documentation, but can do the basic Speed x Distance calculation over a stretch of my layout. 

Any help in rationalising this Loco's performance would be most welcome.

Many Thanks 

PA retired RN Engineer.

[96RAF]

You could try, if your decoder supports it, setting the Vmax CV to a lesser value. You should then alter Vmid proportionally as well to suit.

 

have you tried reading the CVs on a programming track to see what values are there and if RM even recognises the decoder?

 

a programming track is simply a length of track connected to the eLink PROG terminals.

[Chrissaf]

How very strange, I would begin to think this post and the one in the link below are from the one and the same person. Almost identical issues, with similar forum user names.

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Anyway, assuming user 'Cowplain' is not user 'cowside'. Have a look at my reply in this other post linked below:

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https://www.hornby.com/uk-en/forum/railmaster-settings-for-gwr-45xx-side-tank/?p=1

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PS - setting up the Hornby test circle isn't always convenient, never mind, just guesstimate and experiment with the setting I highlighted in the other post.

[Cowplain]

How very strange, I would begin to think this post and the one in the link below are from the one and the same person. Almost identical issues, with similar forum user names.

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Anyway, assuming user 'Cowplain' is not user 'cowside'. Have a look at my reply in this other post linked below:

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https://www.hornby.com/uk-en/forum/railmaster-settings-for-gwr-45xx-side-tank/?p=1

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PS - setting up the Hornby test circle isn't always convenient, never mind, just guesstimate and experiment with the setting I highlighted in the other post.

Thanks Chrissaf and RAF for your input.

To clarify I am not cowside and do understand the the programming track issue. I do not use a "programming track" within my layout, but do use a segregated "Rolling Road" as my programming track.

As I mentioned, I do understand the principle around the Speed/Distance calculation, but am a bit "foggy" on how to transpose that collated data into programming the loco's "chip" into CV input.

Any help/advice would be most welcome.

 

[cowside]

Cowplain and Cowside are different people with similar questions!

[Fishmanoz]

RM doesn't program any CVs to set its scale speeds.  It does it by the throttle setting it uses for shunt and cruise speeds.  It is these you set via the calculation. You don't write CVs.

[Chrissaf]

Some maths......very basic just to give an 'in principle' flavour of what the RM 'scale speed' setting does (in my opinion).

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The documented Hornby scale speed testing track is supposed to be 6.274 metres long. At a 1:76 scale this equates to near as dam it 1/3 of a mile.

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At 60 MPH true speed, one mile is covered in 60 secs, thus to travel 1/3 mile should take 20 secs.

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If the model takes longer than 20 seconds to travel 6.274 metres then it is travelling at less than 60 MPH scale speed. If it takes less than 20 seconds, then it is travelling faster than 60 MPH scale speed.

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For the sake of this example, let us assume the model took 10 seconds to travel the 6.274 metres.

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Thus, the indicated scale speed is 60 MPH, but the actual scale speed the model is travelling at is 120 MPH.

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Thus, RM uses the 10 second test 'distance traveled' measurement to modify the throttle response within RM itself to reduce the output power to the loco by half. Thus artificially curbing the actual speed of the loco on the track by half (just a very rough and ready interpretation of power vs model speed).

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The intention of the maths above is just to show the principle. In reality, the Hornby test requires two things. The loco is driven on the track at full throttle to take the measurement, and the documented top speed of the real life loco is also entered into the RM calculator as well. See page 35 of the RM manual.

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Thus, my understanding is that if you enter the true 'real life' top speed of the loco in the RM calculator and guesstimate the number of seconds. If the loco model appears to travel too fast, then reducing the value of the 'seconds' entry should make RM slow the loco down and increasing the value of the 'seconds' entry should make RM speed the loco up.

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Therefore play around with the 'seconds' entry until the model travels at a speed you are happy with that appears to be consistent with the MPH figure indicated on the RM throttle window.

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Note: As you are not writing CV's to the loco, this will have no effect on any other controller other than RM. Elite physical knobs used manually for example.

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Note also: 'Use Scale Speeds' needs to be enabled in the main RM Settings Screen, else this configured feature has no effect.