Graham Radish Posted January 21, 2019 Share Posted January 21, 2019 (edited) Hello, The class 70 has a top speed of 75MPH, how would i go about putting in the correct maximum speed in cv#5 ? at the moment its set to 115. Cheers. Edited January 26, 2019 by Graham Radish Link to post Share on other sites More sharing options...
RMweb Gold Phil Bullock Posted January 21, 2019 RMweb Gold Share Posted January 21, 2019 Set up a test track with a known distance and adjust CVs until you get the desired top speed. This may help Bullock's patented scale model relative velocity calculator.xlsx Phil 1 Link to post Share on other sites More sharing options...
Phil S Posted January 21, 2019 Share Posted January 21, 2019 'Scale Speed' is an interesting concept and potential can of worms.... Depending on what is meant behind the question 8-) There is the direct scaling of distance, whilst keeping time constant.... I.e. 1/76 of the full size distance in the same time. However, not everything scales linearly.... Such that when filming models, with the intention that they LOOK like the full size model, then 'time' ( or recording v playback speed ) needs to be adjusted ... Or features like wobble and bounce will appear unnatural. ....but unlike when filming 'Thunderbirds', most railway modellers don't have live-time-rate adjustment. Another consideration, if trying to match a timetable, is 'selective compression' of the distances between 'places' (stations).... But this is likely to be heavily related to the size of the modelled layout! Cv5 is not available on all decoders... Such as the basic Hornby and tts decoders ... But I believe the rail master software offers an alternative method of choosing a software-set maximum speed .,. Some other control software offers a similar choice of Speed in km/h / mod. Or % of maximum The simplest method is to udevan oval of track ... Of known length ., and time the loops ( or 10 loops / 10 ) Link to post Share on other sites More sharing options...
Dr diesel Posted January 22, 2019 Share Posted January 22, 2019 Hi Graham Go to www.modelbuildings.org If on your mobile open the home menu on the right side To reveal More Resources click on that. Scroll down to FREE TOOLS click on that Scroll down to Scale Speed Calculator Click on that. Now Bookmark it BINGO regards Jeff Link to post Share on other sites More sharing options...
Graham Radish Posted January 22, 2019 Author Share Posted January 22, 2019 Excellent, This is my result: Link to post Share on other sites More sharing options...
lennie Posted January 22, 2019 Share Posted January 22, 2019 Dont forget to set CV6 once you are happy with CV5 setting. Can't find my chart, but I think it's finding a % of CV 5 and using that value for CV6. Personally I use 40% 1 Link to post Share on other sites More sharing options...
Dr diesel Posted January 22, 2019 Share Posted January 22, 2019 So Graham Just out of interest How far out was you with cv5 set at 115? Link to post Share on other sites More sharing options...
Graham Radish Posted January 22, 2019 Author Share Posted January 22, 2019 (edited) I set it to 115 as a guess and its pretty much spot on lol 120 is correct Edited January 22, 2019 by Graham Radish Link to post Share on other sites More sharing options...
Gibbo675 Posted January 22, 2019 Share Posted January 22, 2019 'Scale Speed' is an interesting concept and potential can of worms.... Depending on what is meant behind the question 8-) There is the direct scaling of distance, whilst keeping time constant.... I.e. 1/76 of the full size distance in the same time. However, not everything scales linearly.... Such that when filming models, with the intention that they LOOK like the full size model, then 'time' ( or recording v playback speed ) needs to be adjusted ... Or features like wobble and bounce will appear unnatural. ....but unlike when filming 'Thunderbirds', most railway modellers don't have live-time-rate adjustment. Another consideration, if trying to match a timetable, is 'selective compression' of the distances between 'places' (stations).... But this is likely to be heavily related to the size of the modelled layout! Cv5 is not available on all decoders... Such as the basic Hornby and tts decoders ... But I believe the rail master software offers an alternative method of choosing a software-set maximum speed .,. Some other control software offers a similar choice of Speed in km/h / mod. Or % of maximum The simplest method is to udevan oval of track ... Of known length ., and time the loops ( or 10 loops / 10 ) Hi Folks, Phil is quite correct that not all things scale, for instance he notes "wobble". Wobble is a pendular motion and therefore is constrained by the formula in the following link: http://hyperphysics.phy-astr.gsu.edu/hbase/pend.html This the mechanism that regulates clocks via the escapement, the longer the pendulum the greater the period between frequency of swing. It is also why real trains that may have a centres of mass between 5 and 8 feet from the ground roll a lot more gently that OO gauge models that do indeed wobble. Gibbo. Link to post Share on other sites More sharing options...
Graham Radish Posted January 22, 2019 Author Share Posted January 22, 2019 Wow just as we speak a class 70 colas rail came past me pulling some colas wagons lol Link to post Share on other sites More sharing options...
Gibbo675 Posted January 22, 2019 Share Posted January 22, 2019 Wow just as we speak a class 70 colas rail came past me pulling some colas wagons lol Did it wobble ? Link to post Share on other sites More sharing options...
Graham Radish Posted January 22, 2019 Author Share Posted January 22, 2019 Did it wobble ? No m8, it stopped right outside the flat but, drove off pretty quick, shocked how big these trains are 1 Link to post Share on other sites More sharing options...
RAF96 Posted January 22, 2019 Share Posted January 22, 2019 The over-fast way model trains ‘wobble’ out of scale time is the same reason scale water and smoke doesn’t work either. Time needs to be slowed to suit also, whilst maintaining set scale velocity. Too many scale factors to fudge at once. Rob Link to post Share on other sites More sharing options...
Phil S Posted January 23, 2019 Share Posted January 23, 2019 Bodies mounted on coil springs ( or a spring ) along with added lumps of weight can achieve some of the effect. .....a Swedish 'Date box' Y6 railcar has a very characteristic wobble ..... And Helga at the Nene Valley Railway is an example of such a railcar. A similar conundrum can be experienced if driving a loco via an inbuilt video camera against viewing it from nearby.....with the differing angle of view in each case. ..my experience is that with the on board camera you will want to drive more slowly 8-) Link to post Share on other sites More sharing options...
RMweb Premium Clive Mortimore Posted January 23, 2019 RMweb Premium Share Posted January 23, 2019 Set up a test track with a known distance and adjust CVs until you get the desired top speed. This may help Bullock's patented scale model relative velocity calculator.xlsx Phil Dear Lord Bullock of Abbotswood Had I known about your toy train whoosh thingy I might have used it. Instead I calculated how far round the layout was in scale miles. Well it is just under a scale mile then worked out how many seconds it would take a train to go round the layout at a set speed. Us DC modellers can't pre sent top speed, and who wants to any how, nothing like a Jinty going faster than Mallard. I drew a speed graph which sits in front of a marker and the clock. Off goes the train, as it passes the marker I note where the second hand is and when it does a lap I note where the second hand has reached. I work out how many seconds and look at my graph and congratulate myself at running a DMU at 55 mph around the layout. At first realistic scale speed seemed very slow but once you get use to them it is easy to set the train trundling along. 1 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted January 23, 2019 RMweb Gold Share Posted January 23, 2019 Has anyone tried one of these? https://www.ebay.co.uk/itm/SpeedWagon-OO-Measure-the-real-speed-of-your-models-last-one/263895564190 Link to post Share on other sites More sharing options...
Graham Radish Posted January 25, 2019 Author Share Posted January 25, 2019 No m8, it stopped right outside the flat but, drove off pretty quick, shocked how big these trains are Also its worth mentioning, real trains have suspension springs to absorb a lot of wobble, models in oo gauge do not. Link to post Share on other sites More sharing options...
Andymsa Posted January 25, 2019 Share Posted January 25, 2019 Something that has made life so much easier profiling cv5 and even cv66/95 is a little device I got from the US. It measures speed in kph/ mph and can be set to required scale. It's the Accutrack 2 model railroad speedometer, here is the link I got mine from althought its out of stock. https://www.ebay.co.uk/p/Accutrack-II-Model-Railroad-Speedometer-Now-for-KPH-Bob-The-Train-Guy/1532690653 I can't recommend this enough and it takes out all the guesswork, so much so that all stock can be set to the same speed. 1 Link to post Share on other sites More sharing options...
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