Loco scale speeds and gearing

[daffy]

Following a comment by @grumbeast on one of the Latest Purchase threads, I am curious as to whether or not manufacturers gear their creations to match the real characteristic speeds of the prototypes. Or maybe some do, and others don't.

I've noticed that some of my locos have quite different speeds for a given controller setting. Also, while some locos have better drive characteristics the more they are used from new, others seem to stay the same or even slightly deteriorate from their out-of-the-Box state. Of course I rather expect old models to be slower or less able to give good performance, but we all do that as we age.

Any observations and experience relating to this would be appreciated.

[grumbeast]

In my experience, older locomotives tend to run much faster with worse slow speed control.  I suspect this is due to older motors being less precise / higher friction / 3 pole not 5 pole.

I know the US loco's I have from Kato have beautiful slow speed control and often a realistic top end.  I seem to remember Model Railroader magazine having graphs of the speed performance of locomotives when they do an in depth review.  This contrasts a little with Kato bullet trains that struggle to attain the higher scale speeds!

[PLD]

Setting aside variations in motors, so assuming the same RPM from the motor for the same input current.

The old Farish range used standard size gears across the range (economies of scale), so the rotations of the motor per revolution of the driven wheels was the same which means a larger wheeled loco would travel further than a smaller wheeled loco, so the answer at least for steam locos is 'sort of...' Diesels I think all had the same size wheels so all in theory all run at the same speed. The exception was the chassis shared by the J94 & 08 shunter which had an extra intermediate idler gear over the the other steam locos resulting in a lower speed.

[nookfield]

I only run diesels/electrics on DCC, but using the default decoder settings I've found that Dapol seem to be closest to real speed. Class 35, 56, 73 and HST I have are very close to scale speed.

With Farish their is a lot a variation Class 55 is close. Class 47 is aprox 50% over scale speed  The Blue Pullman tops out at scale 151mph (max is 90mph)

The fastest I have is a 9 car pendolino which reached a scale 202 mph

[njee20]

Newer Farish 66s run much more slowly than the older ones. Think it changed at the same time as they went to 6-pin sockets. I only noticed when testing something else!

[bluedepot]

I think dapol 58s and 56s are too slow at top speed but very good for slow running

their is a big variety in top speeds between locos i have - generally farish seem to be faster


tim

[nookfield]

I think dapol 58s and 56s are too slow at top speed but very good for slow running

their is a big variety in top speeds between locos i have - generally farish seem to be faster


tim

The three class 56's that I have, have a top scale speed between 85 - 90 mph, which is slightly faster than the prototype top speed of 80 mph

[PLD]

I think dapol 58s and 56s are too slow at top speed but very good for slow running

The three class 56's that I have, have a top scale speed between 85 - 90 mph, which is slightly faster than the prototype top speed of 80 mph

Your reported differences are as likely to be differences in the output of your controllers as they are the performance of the individual locos...

My reading of the OP is not simply about how quick any individual model will go, but more about do manufacturers tune the locos so that if you have one loco where the prototype has a top speed twice that of another then the model should be going twice the speed for the same controller at the same setting...

[ntpntpntp]

My reading of the OP is not simply about how quick any individual model will go, but more about do manufacturers tune the locos so that if you have one loco where the prototype has a top speed twice that of another then the model should be going twice the speed for the same controller at the same setting...

Once a manufacturer has achieved a combination of motor and gear ratios that gives reasonable running across the board, those same components are likely to be used where practical in other models as a "known working" mechanism and for economies of scale when sourcing components.  Obviously it also depends what will physically fit in the model.  On top of that you'll get differences in speed for locos with the same basic mechanism but different size driving wheels.

I've certainly come across models with noticeably lower gearing which does indeed give excellent slow running for shunting, if sometimes at the expense of a little more noise in the gear-train. So in some case yes, the manufacturer has given some thought to "tuning" the model to suit its purpose.

I've also come across models which will run nicely at slow speed but also literally fly round the track at way beyond a realistic top speed! Some of the japanese chassis come to mind.

[daffy]

Indeed, as @PLD noted, I was interested in accuracy of gearing across models, as this followed on from two recent purchases I was testing on a 24 foot test loop.
Both locos are of Swiss, SBB prototypes. The first, an Re 460, built in the 1990's and still in extensive use today, has a top speed of 144 mph. The other, an Ae 6/6, built in the 1950's-1960's, has a top speed of 78 mph.

With my new models of these at the same controller setting, the Re 460 would complete a loop in 19 seconds, whereas the Ae 6/6 took 26 seconds. This pleased me, in that it suggested that possibly some consideration had been given to the prototype performances.

However there was an error in my testing experiment. One was a Fleischmann model, and the other from Kato. So I tested with different Re 460's from three different manufacturers, Fleischmann, Kato and Minitrix. A full range of timings ensued, with six locos giving a range, at the same setting, between 18 and 25 seconds.
The error now is that only one of these locos is brand new, the others having various ages and usages.

So, with probably meaningless results from my testing, I threw the question into the Forum pit just to see what views and experience was out there.

[TalyllynJon]

Many years ago when I was a kid I had a Saturday job in a model shop. They had a massive 00 layout which was open to the public during summer weekends and I'd happily spend all day sat in the control cabin driving the trains around. I remember one time a guy who kept looking at his watch and scribbling on a bit of paper. Eventually he came up and complained that he'd worked out one of the trains (8 coaches behind a Lima Western) was travelling at a scale speed of nearly 250 miles an hour. But I was about 12 at the time so I saw it more as a challenge and replied something along the lines of 'Wow - and that's not even top speed - Let's see if it can hit 300mph on the next straight!!!'