Hi all and Happy new year...
During my last operating session, I was just wondering how to make my loco starts and stops more realistic, less sudden, and less 'jerky'.
I seem to remember one of the main controller manufacturers came out with a panel with separate regulator and brake levers plus an "inertia" setting adjustment ? H & M ? Hornby perhaps ?...
It occurred to me that there are two main approaches :
1. Mechanical - motors with flywheels (would these fit in a typical 009 loco /gearbox ?)
2. Electronic - some sort of capacitor-based system maybe ?
I have yet to read anything about such systems in the smaller scales and /or books on model railway electronics.
Would be interested in your views, especially "success" stories. I understand the Pendon Museum have cracked the problem...
BTW I now have sprung buffers fitted to my 'road-ends' in case I get it wrong (with rubbish driving !!).
Best regards,
Dave
I am obviously not up to date with modern controllers as I had thought this was a fairly common feature. Quite a few years ago (late 1970's I think) Codar had an inertia/brake control which could also, usefully, be turned off if desired. I have one which still works - its age now attracts the occasional comment. It, of course, prededes DCC.
Happy New Year to all
Peter
Gaugemaster still do "simulator" controllers together with their lifetime warranty, link to the panel mounted one which is fine for 009/HOe:
http://www.gaugemaster.com/item_details.asp?code=GMC-U&style=&strType=&Mcode=Gaugemaster+GMC%2DU
If you have the right controller for the chassis then they will start and stop in a realistic fashion by slowly turning the controller up or down.
You should be able to get almost all chassis to do this with a Gaugemaster W or Gaugemaster Combi.
You will not be able to get this with an older rheostat type controller like and H&M.
However the chassis have to be in good order, some older chassis, the Minitrix ones for example, tend to need more power to get them to start moving, also all the Tiny Japanese chassis, with the exception of the Kato Protram chassis are geared too high so again the tend to need more power to get them moving.
Brian Meldon
This may be of interest
https://www.world-of-railways.co.uk/news/hornby-launches-app-for-model-railway-control?utm_source=Communicator&utm_medium=Email&utm_content=buttonLink145&utm_campaign=Breaking+News%3A+Hornby+2020+announcements&_ccCt=tBSikgi2NZlMmO45QVs9DXZWoKc5JXH2WhQ1LjFeTwJR8Dq2jEOqIe~gqpRqXqVn (https://www.world-of-railways.co.uk/news/hornby-launches-app-for-model-railway-control?utm_source=Communicator&utm_medium=Email&utm_content=buttonLink145&utm_campaign=Breaking+News%3A+Hornby+2020+announcements&_ccCt=tBSikgi2NZlMmO45QVs9DXZWoKc5JXH2WhQ1LjFeTwJR8Dq2jEOqIe~gqpRqXqVn)
Quote from: Dave Cooper on January 05, 2020, 16:45
2. Electronic - some sort of capacitor-based system maybe ?
If you are thinking about putting a capacitor in each loco as a "flywheel", there are issues in a DC situation:
You'll need a large value to get any discernible effect, which means it will be physically big AND it will be polarised - so it will blow up if you reverse the supply voltage (quite spectacularly). There are ways to make an electrolytic capacitor "ac" but it will reduce the capacitance and increase the volume required to install it.
Similarly you won't want to stick a large capacitor across the track feed...
{As I understand it, the use of "keep-alive" capacitors in DCC means putting a large value cap on what is effectively the dc supply bus local to the DCC chip and it keeps the chip alive rather drive the motor. This gets round the requirement for an "ac-friendly" capacitor}
PS, you'd be better off if you could move this thread to the "Electronics and Control" section.
.. where I see you posted something similar a while ago.. :)
Thanks for the replies folks. Just found an Australian-based system called "CDA" on YouTube that also has separate controls for throttle and brakes and looks quite smooth. (Not sure if this is available in the UK though).
It seems that most 'solutions' are electronic so far...
Hugh: the reason for putting it under "Locomotives" and not "Electronics and Control" is that I was interested to see if there were any 'mechanical' systems as well. Eg I've seen a very effective '0' gauge flywheel-based system in operation at a show. The operators thought this would probably scale down to '00' but weren't sure about '009' - boiler sizes maybe ? Perhaps under a diesel shunter's bonnet ?
Regards,
Dave
From the description that Australian one sounds the same as that gaugemaster one I linked you to.
Minitrains locos and chassis have a 'mechanical' flywheel, don't they (up under the cab roof)?
David.
Hi Hobby
Thanks for the Gaugemaster link. Yes, I imagine they are similar...
Not really sure how to post a link to the CDA system but the demo is quite interesting for those of us who have never seen such a set-up in operation.
So, here goes:
https://www.youtube.com/watch?v=yhTVEwUiAfo&t=55s
Regards
Quote from: clayliner on January 06, 2020, 18:16
Minitrains locos and chassis have a 'mechanical' flywheel, don't they (up under the cab roof)?
David.
Yes, they do.
Jeff S.
Quote from: Jeff Schumaker on January 07, 2020, 01:08
Quote from: clayliner on January 06, 2020, 18:16
Minitrains locos and chassis have a 'mechanical' flywheel, don't they (up under the cab roof)?
David.
Yes, they do.
Jeff S.
Yes they do have a flywheel.
However they only have a three pole motor that has precious metal wire wipers in place of brushes.
They do run very well, but this is as much about the gearing as it is the motor and the flywheel.
Brian Meldon
Quote from: Dave Cooper on January 06, 2020, 20:49Not really sure how to post a link to the CDA system but the demo is quite interesting for those of us who have never seen such a set-up in operation.
https://www.youtube.com/watch?v=yhTVEwUiAfo&t=55s
That's exactly the same as the Gaugemaster one (I had one in the past)...
Is the Minitrains flywheel driven off the back /top of the motor or some sort of gearbox drive ?
I've got something in the workshop that I'd like to experiment with - may try proving it on 00 first of all before going to 009...(Peco "James" ?)
Can anyone suggest a suitable mass for the flywheel as I'll probably have to 'turn down' my lump of brass.
Thanks,
Dave
The Minitrains one is attached to the other end of the shaft to the gears. Look at the first photo on this link.
https://www.rmweb.co.uk/community/index.php?/topic/88311-chivers-kits-on-a-minitrains-fc-chassis/
The Minitrains motors have a shaft at both ends. One end has the worm the other the flywheel.
When I replaced a Minitrans motor a few months ago I did try the loco without the flywheel and there was no obvious diferance in the performance! I did however re-fit the flywheel.
As I mentioned before in these Minitrains locos their good running is more about the gearing than it is the flywheel.
Brian Meldon
You can work out the energy stored in a flywheel here:
https://www.botlanta.org/converters/dale-calc/flywheel.html (https://www.botlanta.org/converters/dale-calc/flywheel.html)
A MiniTrains flywheel, unless spinning extremely quickly has minimal energy stored and at low speeds are probably a waste of space IMHO. DCC and Radio Control battery power are probably the best way to go for smooth low-speed running.
To be fair the simulator controllers mentioned at the beginning do work very well, as do the modern "ordinary" analogue controllers by GM. I remember spending a whole afternoon on a model of Longridge station at a Preston MRC openday shunting in the yard using a GM simulator controller and using a Triang X04 powered loco, if you can do it with one of those motors then you should be ok with a modern loco.
Whilst you can use DCC or RC you don't have to. Modern DC controllers are a world away from the old H&M and Triang and HD controllers, as are modern chassis. Times have moved on.
Quote from: Dave Cooper on January 08, 2020, 10:19
Can anyone suggest a suitable mass for the flywheel as I'll probably have to 'turn down' my lump of brass.
Thanks,
Dave
Thinking about the physics it's not so much about total mass but where that mass is. I've not done the calculations but I'd have thought that a flywheel with a 'fat' rim and a hollowed-out center (so the mass is concentrated towards the outer edge) would have more of an effect than a 'solid disc' of the same mass. The same may be true for 2 flywheels of the same overall diameter as a 'hollowed-out' one may have more angular momentum than the 'solid' one with greater mass.
Essentially though the size of any flywheel needs to be as big as possible and as heavy as possible to have maximum effect.
Hmmm, much food for thought there folks...
Looks like the way to go would be a 'modern' controller with a 'modern' loco (haven't tried that combination yet !) - ie the "Electronic" route.
However, I have some older chassis (eg Diesels with pancake motors) that may be fun to experiment with - just to see what could be achieved...I think I would go for a heavy(ish) flywheel, axle supported at both ends, linked to a 5-pole motor. Strikes me that if the flywheel was placed near-centrally, it could also aid traction ?
Once I have got one or two other projects out-of-the-way, I'll let you know how I get on.
Thanks for all the input so far,
Dave
If it's the Lima 4 wheel diesel shunter bin it.
No it's not that one - but, there are a couple of Lima's lurking in dark places - having seen their performance though I know what you mean !
Dave
Nothing to do with flywheels, but in defence of the much maligned Lima chassis in the 4 wheel diesel, I've got 3 of them, one with the pancake motor and 2 with traditional motors - and no sign of them ever being re-motored as far as I can see. All 3 of them work fine, very smooth and responsive and all 3 are amongst the best very slow runners that I have. The only difference between the one with the pancake motor and the other 2 is that the one with the pancake motor makes a very convincing 1:76 scale "diesel sound" whilst the other 2 are silent!
Maybe I have just been lucky.
Mick
You have, Mick... I am referring to that thing which looked like some overscale American body numbered D2xxx in BR green and with the pancake motor. Horrible thing!
Quote from: Hobby on January 09, 2020, 09:23
You have, Mick... I am referring to that thing which looked like some overscale American body numbered D2xxx in BR green and with the pancake motor. Horrible thing!
These things also came in BR blue as well as several (at least 4) US railroad colours.
Yes they are quite poor chassis. Out of the 15 or so I have aquired over the years I had two that ran ok, I still own one that works ok under a Matchbox diesel body, and have a box of bits from the others!
Some of these also have a probelm with the brass gears on the back of the wheels being too large (or the wheels too small) and shorting out on electrofrog point blades!
This beasty!
https://www.ebay.co.uk/itm/Model-Railway-N-Gauge-Lima-B-R-Diesel-Shunter-D2790/264590416186?hash=item3d9ad1593a:g:deEAAOSwlTheE3il
Quote from: Dave Cooper on January 05, 2020, 16:45
BTW I now have sprung buffers fitted to my 'road-ends' in case I get it wrong (with rubbish driving !!).
You could try isolating one rail for last 2 or 3 cm of track so the loco stops. You should be able to do something clever with diodes so you can still back up, but that would depend on how you wired it up ;)
Hi Stephen
Yes, I've already got isolating 'dead-ends' but I still manage to "back" trains into the buffers occasionally though bad driving !
Also, on the standard gauge platform, some twin-bogie diesels actually 'span the gap' - interestingly, I don't have this problem on the NG platform.
There's a moral there somewhere...
Dave
Dear David,
Reading through all the comments I suspect I might be the most competent to provide you an overview. Let's dissect your question:
Option 1, flywheel:
It requires space in the engine, which even in small H0 is insufficient for creating a marked inertia, i.e. 'train mass' effect. I have the original Roewa/ ROCO V215, which has 2 massive flywheels (1st ever commercial model to do so, at least in Europe) that create a discernible inertia, but that's hardly more than an real engine running light, about 4cm from full speed. Each of the flywheels is bigger than some 009 engines! This comment already highlights the issue with flywheels: speed, i.e. their inertia is speed dependant. At low speeds, where you need the inertia the most (to overcome contact issues) they don't give you enough.
Flywheels are commonly found in commercial off-the-shelf (COTS) models, and they have their place and usage for 2 purposes:
1. Overcome contact issues.
2. Smooth uneven motor performance, e.g. 3-pole and 5-pole motors.
As stated, to do their job they need size and speed, i.e. not really much use on small models, especially at the low speeds typical on narrow gauge lines.
To simulate train mass, i.e. achieve more than 100mm 'coasting', you need sizes bigger than H0/00 allow.
Option 2:
Electronics.
Here we have to split the subject into 3 sections.
1. Digital Control: you can set specific parameters in your digital chip to simulate train mass, for acceleration and braking individually. Even the most basic DCC chips facilitate that, easy-peasy. Only snag: as the chip does not know the size of train you're hauling it doesn't necessarily match your train, so you need to make a compromise.
2. Analog controls:
2.1 Capacitors on the track voltage have already been mentioned, and we experimented with those. You need a capacitor the size of 2 fists (11000 mF, if I remember correctly) to achieve about 500mm coasting for a big H0 loco (Rivarossi V320 was the guinea pig), and you need 2 of those because of the polarity issue electrolytic capacitors have. Goldcaps weren't invented then, they bring the size down somewhat, but not enough. Problem with this solution: the coasting distance is heavily dependant on the motor and train load, a high-current motor (Rivarossi; Maerklin) might coast 500mm, while a low-current motor (coreless) will do 2500mm;, and a heavy train pushes those figures up.
2.2 Electronic mass-simulating controllers use a fairly small capacitor to 'delay' the power transistor's response to your input. This way the inertia performance is more or less independent from the motor/ gear-train quality, and engines perform roughly similar, unless they have serious mechanical issues (cheap motors, insufficient gearing). I have a DIY-version (built following an article in a 1980s Model Railroader), which cost about £5 to build. If the handheld controller is unplugged, the engine coasts to a standstill over about 15m, if you accelerate, you need 700mm from standstill to top speed, and braking is about the same distance (unless you use the emergency stop button). Controls are push buttons, i.e. there is no knob to turn. Snag with this solution: no easily adaptable to various locomotive performances (some have controls to facilitate that, but unless you do trials and keep a record of settings for each engine, there'll be no consistency), and not proportionate to train mass.
Common snag with these solutions: they don't help with contact issues. That's why 'staying-alive' solutions are offered for DCC (which are too big for a lot of 009 engines).
Option 3:
Clutch that facilitates free-wheeling. fantastic solution that reflects train mass and helps with contact issues. More interestingly: it can be made small enough to fit most 009 engines (self-engaging gear-trains have been used in wrist watches).
3.1 Centrifugal clutch; I drove a class 08 at a Fremo meeting, which was fitted with centrifugal clutch, and it was a revelation. Coasting distance is seriously dependant on train weight and slope (up to 2,5m; !), a real feel of driving the real thing. Braking is by reversing, and has to be done with a lot of sense, great.
3.2. Self-engaging gear-train, Rivarossi produced a BR18 with this neat trick, and I got me one when they were sold as bargains. They weren't popular in the market as these engines were not compatible with existing layouts and any automatic block control! But performance is level-par with the centrifugal clutch, minus 1 detail: no braking, you can't engage the gear-train reliably/ predictably by going into reverse, and if it does, its a crunch stop. Shouldn't be an issue really as the rolling resistance of our models roughly equates to a wagon with brakes at least half on, but modellers are so fuzzy. I love it, it's a skilled drivers only engine, and with the driving school wagon attached (see John Allen for that one) provides endless fun for even experienced driver! :laugh:
Common snag to both these options: trains and engines can't be stopped on slopes; as their is no brake they'll roll all the way to the bottom if power is off!
There are your options, so take your pick, none is without a downside, but some are better than others; so choose wisely!
Food for thought
and a Happy New Year to all!
Waldschrat
I may be wrong, and it's a long time since I studied physics, but I suggest that it's inertia that would probably be greatest at low speed, not to say at rest. What increases with speed is, I think, the momentum.
David.
Quote from: clayliner on January 11, 2020, 19:04
I may be wrong, and it's a long time since I studied physics, but I suggest that it's inertia that would probably be greatest at low speed, not to say at rest. What increases with speed is, I think, the momentum.
David.
You are correct:
Inertia - A property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.
Momentum - the quantity of motion of a moving body, measured as a product of its mass and velocity (including angular velocity i.e. rotational speed).
I must say I liked the sound of Leprechaun's clutch idea(s) until I remembered that my 009 line has quite a gradient coming up from the fiddle yard to the goods sidings /station. I was going to put a signal and refuelling depot part way up...
Yes, my '0' level physics 'says' - inertia (has a tendency to stay put, whether moving, or not). Momentum generally tends to keep things going (until something else intervenes).
However, one of my Christmas presents was an Arduino starter kit. Having read some of the 'capabilities blurb' of microcontrollers, I think it should be possible to apply a 'brake' to a clutched loco. This could be as crude as a micro servo lowering a peg down onto the track (to stop a runaway train on a grade) or, something bearing on the clutch /gearbox - both triggered by the loco coming to a stop.
Chaps,
I've got a problem here, which is: I'm not a native English speaker. I just spent a happy hour trying to get my head around your comments regarding inertia and momentum, and I can't.
Reason is that I can't tally the statement that inertia being a material property with my physics knowledge. To me inertia and momentum are physically the same thing observed in a different way, very much like centrifugal - and centripetal force?
Isn't it that both, inertia and momentum, are the same effect of mass, the first observed as the reluctance to change speed (vector and value!), the latter observed as impact?
Educate me, please!
Regarding the brakes on your train (clutched engines on slopes), there are 2 potential solutions, both with side effects:
1 .You can add axle mounted track wipers or electrical pick-ups to increase friction that holds your train on slopes. Downside: the engine has to work harder, and you're in trouble humping your train. Upside: cleaner tracks.
2, You can mount bristles in the track that 'catch' the train, be that brush bristles vertically that catch the axle, or spring wires that 'clamp' the flange against the rail head. Downside: the engine has to work harder to pull the train through that track section; upside: you can still haul comparatively longer trains over the rest of the layout. Of course, installing a brake lever that engages and disengages the feature resolves the downside issue.
On second thought option 2 might be viable as a magnetic solution, which could be switched electrically.
Don't let me down, answers please!
Cheers
Waldschrat
From https://www.britannica.com/science/inertia (https://www.britannica.com/science/inertia)
Inertia, property of a body by virtue of which it opposes any agency that attempts to put it in motion or, if it is moving, to change the magnitude or direction of its velocity (https://www.britannica.com/science/velocity). Inertia is a passive property and does not enable a body to do anything except oppose such active agents as forces and torques. A moving body keeps moving not because of its inertia but only because of the absence of a force (https://www.britannica.com/science/force-physics) to slow it down, change its course, or speed it up.There are two numerical measures of the inertia of a body: its mass (https://www.britannica.com/science/mass-physics), which governs its resistance to the action of a force, and its moment of inertia (https://www.britannica.com/science/moment-of-inertia) about a specified axis, which measures its resistance to the action of a torque (https://www.britannica.com/science/torque) about the same axis.
See Newton's laws of motion (https://www.britannica.com/science/Newtons-laws-of-motion).
From https://www.britannica.com/science/momentum (https://www.britannica.com/science/momentum)Momentum, product of the mass (https://www.britannica.com/science/mass-physics) of a particle and its velocity (https://www.britannica.com/science/velocity). Momentum is a vector (https://www.britannica.com/science/vector-physics) quantity; i.e., it has both magnitude and direction. Isaac Newton (https://www.britannica.com/biography/Isaac-Newton)'s second law of motion states that the time rate of change of momentum is equal to the force (https://www.britannica.com/science/force-physics) acting on the particle.
See Newton's laws of motion (https://www.britannica.com/science/Newtons-laws-of-motion).
From Newton's second law (https://www.britannica.com/science/law-of-force) it follows that, if a constant force acts on a particle for a given time, the product of force and the time interval (the impulse) is equal to the change in the momentum. Conversely, the momentum of a particle is a measure of the time required for a constant force to bring it to rest.
Difference between Momentum and Inertia| Momentum | Inertia |
| Momentum is a vector quantity as it the tendency of a body to remain in motion. | Inertia is a scalar quantity as it is the resistance offered by the body to motion.
|
Momentum is denoted as 'p'.
| Inertia is denoted as 'I'.
|
The momentum of a body of mass 'm' moving with a velocity of 'v' is calculated as p=m×v
| The inertia cannot be calculated using a formula.
|
Linear momentum and angular momentum are the two types of momentum.
| Inertia of rest, inertia of motion and inertia of direction are the three types of inertia.
|
Momentum depends on mass and velocity.
| Inertia depends only on mass.
|
The total momentum is conserved.
| Inertia has nothing to do with the conservation of energy.
|
The difference between between momentum and inertia should be understood clearly as these are an important topic in Physics.
To try to simplify things (hopefully, not over-simplifying), I have in mind a spinning gyroscope:
This, I believe, has both inertia and momentum. It also has "precession" if you try to disturb it's motion - it doesn't 'like it' ! I see this as a combined (side) effect of both inertia and momentum...
In the gliders that I fly, we have some instruments controlled by gyros. Left to their own devices, they will gradually 'wind down' and the instruments become misleading /dangerous - so, they have either electric motors, or, the moving airstream to keep them going. Hence, (little-by-little) inertia gets a "kick" and momentum gets a "boost". For aerobatics, we have to "cage" them, otherwise they 'topple' and become useless. Caging instantly kills both inertia and momentum as far as I can see. It works - otherwise there's an awful lot of planes up there about to crash !
(BTW all this ignores friction, stiction, angular momentum, fourth powers of moments of inertia and stuff that I should know but have forgotten how to calculate !)
Thanks for trying, but still confused. Especially bringing both explanations together. Any gyroscope is a gyroscope on a gyroscope, as in physical terms the earth is a giant gyroscope. That's why a gyroscopic compass works (and always points towards geographic North as opposed to magnetic North). All gyroscope when left to their own devices will eventually point to geographic North (as long as they are kept spinning.
And as we all have tried with our bicycle wheel: if I spin it and let go of the axle at one end it doesn't fall down, but rotates around the supported end of the axle. That's is caused by nutational forces, and is a result of inertia and momentum.
Inertia is a vector as it can only be observed on objects that are accelerated, which is a vector. And it manifests itself in the resistance to that acceleration vector, i.e. the force required to accelerate; be that either the vector direction or the scalar quantity.
Confusion reigns supreme; - I'm off to bed hoping for enlightenment in my dreams.
To be continued....; but can we stay we with the topic here please?
Cheers
Waldschrat
Oh dear ! Looks like my attempt at 'simplifying' has failed...
Let's try : spinning gyroscope is analogous to a spinning flywheel ie it wants to keep going until other things get in the way eg friction, air resistance etc.
A centrifugal clutch (even on 'tick-over') is a spinning flywheel (mass, velocity, inertia, momentum etc). As the motor spins up, the clutch engages, the 'flywheel effect' gains momentum, overcomes inertia and friction (partially) and the loco moves (accelerates).
Have a feeling I'm teaching my granny to suck eggs here, but, hopefully, we are back on topic !
Dave
Quote from: Retiarius on January 12, 2020, 12:56
The difference between between momentum and inertia should be understood clearly as these are an important topic in Physics.
Trying to get people to understand that Momentum is not a force or energy is just as hard, we only briefly mention inertia and relate it to mass for both GCSE and A-Level. But that won't be my problem after July 8)
Stephen
I recon Physics is like Pure Maths, you either "get it" or you don't with no in between! I am in the latter camp, this thread has been a "whoosh" moment!! :)
Things in motion have momentum. Heavier or faster things have more momentum. Real or model trains are only accelerated by application of power or by going down a hill, and only slowed by friction or climbing hills or running into things. Trains with more momentum need more of these effects to achieve a given change of speed. We use circuitry or software or judicious turning of the knob to make our model trains simulate having more momentum than they really do. Sorted.
QuoteQuote from: Hobby on January 18, 2020, 07:49
I recon Physics is like Pure Maths, you either "get it" or you don't with no in between! I am in the latter camp, this thread has been a "whoosh" moment!! :)
Last year I undertook a degree-level "math" course (on-line, via Caltech). We covered spherical trig' (ugh), analytical geometry (double-ugh), matrix algebra (triple-ugh) plus, some fairly 'hairy' calculus...
Yesterday, I watched a TV programme on "Quantum Disentanglement". I am now convinced I know nothing !
As for momentum and inertia in model railways - the electronic route seems the most sensible. Will I follow this path ? Probably not - no fun in solving a problem that has already been solved...
I remember having a tinplate car when I was about 6 or 7. It was battery operated and "remote controlled" in that steering was by Bowden cable. It used to pull away nicely and when I took it apart I found it had a miniature fluid flywheel in it. I could see that might work nicely in O gauge models, but not smaller.
Somewhere I have seen some very small centrifugal clutches, too big for 009, but still very small.
Hi Graeme
At about the same age as you were, I had 3 tinplate cars (Ferrari 250, Jaguar 120, Austin Healey 3000). I use to race them.
They had a rubber-covered friction wheel which engaged with the floor when you pressed down on the front bodywork. You then pulled back to (I imagine) wind up a clockwork drive. On release, each car would slowly accelerate up to speed - friction wheel doubled up as a flywheel /clutch ?
Must only have been around 10-15mm in diameter to fit in the cars so could fit in a loco cab I should think. Where are those toys now ?
Quote from: Dave Cooper on January 18, 2020, 19:30
Must only have been around 10-15mm in diameter to fit in the cars so could fit in a loco cab I should think. Where are those toys now ?
Those that didn't die of tin worm probably got trodden on and any that survived because the hapless children who owned them were not allowed to play with them as they "had to be kept in good condition" are probably in auction houses or lurking on eBay at outrageous "collector" prices!
Mick
For a moment I thought you're talking about the Triang Minic cars, but they have plastic bodies. Yes, the flywheel on those is only about 12mm (1/2") and relies on 2-stage gearing to get high rpm, thus storing enough energy. As I have these, I can confirm that the energy is rather less than one would hope for; and the mechanics are not very long-lasting, only 1 of 5 cars is still working. :police:
Cheers
Waldschrat