[34C]

General question, not specific to the model prompting it, which is Sonic's A5.

The long established 'OO compromise' of constant 4mm/ft scale for all but the track gauge (which is at 3.5mm/ft of HO) has served us quite well for production of working RTR OO models of UK prototypes which will get around the seriously underscale curve radii of set track systems. The current set track - and specifically the R2 substitution radius points - effectively defines what RTR OO models must negotiate; and the various brands have chosen their own methods for achieving this. The usual recourses include: omitting flanges, including fouling detail as user optional, underscale wheel diameters, altering exterior dimensions and body forms, with varying degrees of finesse...

One further method has been simply not to introduce a model of a subject which really cannot be made compliant; but lately the expanding range of subjects offered has led to the introduction of RTR OO models which will not negotiate the set track point.

And thus the question: should the brand management make the customer aware that a product isn't suitable for set track operation, and if so, how should this be described?

 

[kiwionrails]

And thus the question: should the brand management make the customer aware that a product isn't suitable for set track operation, and if so, how should this be described?

An interesting question indeed.

Unfortunately the reality of a brand supplying the general release of a model to only be compatible with Peco Streamline (as the most commonly available non-set track turnouts in the UK) would likely be not viable for a couple of reasons;

• The big one: Quite frankly people don't read product listings properly (and/or understand them), so the brand/retailers would have a lot of returns to deal with from people who are unable to run it on their layout.
• If you provide a 'finescale' and 'trainset' version, this goes back to (what I thought was) part of the intent behind the main and 'Railroad' Hornby ranges. You've then got double the number of versions to stock
• Supply the 'finescale' components in a detail bag to fit/substitute - people moan that these aren't pre-fitted and/or 'paying for details they can't use'....

That said, providing the designed-in ability to 'upgrade' the model to resolve some of these could work, e.g;

• 'finescale' components supplied in-box to fit later. Those who care will fit them, those who don't won't (although ofc see above about people moaning in both directions..! )
• 'Finescale' components supplied as an add-on item. - I believe this is what Accurascale(?) did for the P4-lot by providing a 1st-party drop-in wheel replacement set (I am however aware that didn't go perfectly either due to the wheel size/etc comprimises)
• Maybe consider comprimiseing things such as buffer height for the 'standard' model such that when the 'finescale' changes are made this is corrected, but is less likely to be a gripe on...

Many different options, and unfortunately you'll never make everyone happy...

 

[34C]

...If you provide a 'finescale' and 'trainset' version, this goes back to (what I thought was) part of the intent behind the main and 'Railroad' Hornby ranges. You've then got double the number of versions to stock...

Here I feel you are putting your finger on the significant question of how this is to be managed; and current practises suggest that this isn't the obstacle it once was.

Hornby have made something of a mess of differentiating 'Railroad' from 'main range': but moving in the other direction, they are thus far maintaining clear water between 'main range' and the 'Hornby Dublo' presentation of premium models. The latter are evidently relatively small volume productions, but it must be working for Hornby as they continue to expand the range.

That could be one way to do it, direct sales only for a finescale production variant of a main range model with the compromises necessary to get through the set track point eliminated, sold at a higher price. (Potentially comes with advantages for the brand's 'main range' too, no need to include additional parts which are incompatible with set track.)

 

[dwb]

Manufacturers who sell track in addition to locos and rolling stock should state what the minimum radius is for a particular model. It is clear from videos that Hornby have published to show progress with engineering prototypes etc that they have a test track containing all the elements from their set track range.

Those manufacturers who only sell rolling stock will still have to test engineering prototypes so it should not be hard for them to publish the minimum radius their models will work on.

But what about 'Finescale' modelling? Is there an established minimum radius? A quick look at the DOGA finescale track standard has nothing to say about minimum radius, not even a recommendation.

If a company has decided to improve the look and solidity of a model by

• Fitting fixed front steps around the front bogie
• Fitting solid connecting rods rather than jointed.
• Reduced the side to side slop of the main drivers in the chassis

it would be helpful to know the minimum radius 'price' paid for such improvements. It can't cost that much to buy a circle of set track and create some cross overs and S curves for testing?

David

 

[kristopher1805]

The problem here is reaching some sort of sales target, lets take the Heljan O2 series, I run these on R6 basically and it is fine but there is little chance of it working R2/3 and R2 points, Peco streamline large radius is OK with this but I never use them on the inside circuits R3,4,5 but onlt on R6 and the same applies to the upper level, so the model has limited appeal to a few buyers and thus they have not proceeded with the other variants. Some Heljan models are better the 47xx is about the best but forget R2, The Garrett manages just about anything,

Bachmann make set track of their own so again as long as it is R2 or better you are probably OK.

Hornby puts a note on the box if it is only suitable for R2 plus - it says so and so far what they say in this regard can be relied upon

So now we come to other newcomers, it would be a brave decision to limit sales to some bigger radius when R2 is clearly the standard and lets face it is the Bachmann and Hornby 9F can get round then what's the excuse, I hope the forthcoming Jones goods makes in R2 and whilst Sonic may be a bit off on the A5/9N that could be adjusted.

My view is then if it cannot handle R2 you are heading for commercial suicide.

http://imgur.com/TELxEqG

So if this monster (P2 from Hornby) will cope with R1 whats your excuse? - I have none but can find sidings in R2

http://imgur.com/mlC7rTL

Nearly but not quite Heljan O2

http://imgur.com/UE5SAgs

See they can manage if they try Heljan 47xx

 

[kiwionrails]

Here I feel you are putting your finger on the significant question of how this is to be managed; and current practises suggest that this isn't the obstacle it once was.

Hornby have made something of a mess of differentiating 'Railroad' from 'main range': but moving in the other direction, they are thus far maintaining clear water between 'main range' and the 'Hornby Dublo' presentation of premium models. The latter are evidently relatively small volume productions, but it must be working for Hornby as they continue to expand the range.

That could be one way to do it, direct sales only for a finescale production variant of a main range model with the compromises necessary to get through the set track point eliminated, sold at a higher price. (Potentially comes with advantages for the brand's 'main range' too, no need to include additional parts which are incompatible with set track.)

Agreed it is incredibly 'interesting' how some of the division between the Railroad/main-stay/'Dublo' ranges have been incredibly blurry.

I do honestly wonder how many of the Dublo models actually get run, however that is a comment for another topic.... (and I'm aware I'm throwing stones in glass houses with it...).

... when R2 is clearly the standard...

And therein lies the issue; basically everyone will have some R2 settrack points somewhere, with early-state people in the hobby using them exclusively.

In some ways it is a pity that no-one has produced a 'double straight' settrack turnout (i.e. based on an R601 double-straight rather than an R600 single). This might be a way of encoraging gentler curves even for 'trainset' users (am not knocking it before someone shouts at me!).

... and lets face it is the Bachmann and Hornby 9F can get round then what's the excuse, I hope the forthcoming Jones goods makes in R2 and whilst Sonic may be a bit off on the A5/9N that could be adjusted.

In some ways Hornby and Bachmann with the 9f had it 'easy', as this prototypically had some flangeless drivers!

I will say that I honestly don't envy the various manufacturers, as no matter what you'll never make everyone happy!

 

[34C]

...But what about 'Finescale' modelling? Is there an established minimum radius? A quick look at the DOGA finescale track standard has nothing to say about minimum radius, not even a recommendation...

That's very properly left to the individual to decide for themself.

For my own particular interest of ECML 1955-62 I can have all the most 'challenging' models - which are traction, both steam and diesel - looking right (exterior consistently at 4mm/ft with correct form, loco to tender distance to scale, all flanged wheels where applicable, all wheels correct diameter over tyres) by use of a 30" minimum radius.

That's an easing from the usual standard for 'OO finescale' of fifty years ago, which was 36" minimum radius if 'big engines' were to be run on the layout; gained by some advance in standards and improved design and manufacturing technique.

...If a company has decided to improve the look and solidity of a model by

• Fitting fixed front steps around the front bogie
• Fitting solid connecting rods rather than jointed.
• Reduced the side to side slop of the main drivers in the chassis

it would be helpful to know the minimum radius 'price' paid for such improvements...

No 'one size fits all' answer, as it depends on how far the designer cares to go in technique. There are options in applying proven features from HO - for example to prevent bogie wheels fouling fixed bodywork by having it mounted on hinged panels - thus permitting adequate flexibility on curves. Likewise coupled wheels can have adequate side control by use of the pick up wipers to aid centering the model on straight track, which permits plenty of deflection for curves; that one at least we have in RTR OO when the designer got it right, a good example Bachmann's 9F, (Hornby's new 9F may well be similarly designed).

...therein lies the issue; basically everyone will have some R2 settrack points somewhere, with early-state people in the hobby using them exclusively.

In some ways it is a pity that no-one has produced a 'double straight' settrack turnout (i.e. based on an R601 double-straight rather than an R600 single)...

There are plenty of layouts with no set track, I promise you. The fairly consistent retailer estimate is that 80% of OO layouts are set track, yet if you look at the shelf space for OO track, Peco's Streamline usually has the lion's share. The reason for this is that it sells in greater quantity...

UK OO set track is of a design already obsolescent when introduced, which was circa 1971, and very limiting as a result. My continental cousins had superior points choices - including double slips - and a greater range of radii, for their RTR HO set track layouts in the 1950s!

What RTR OO needs is a completely new set track system with considerably more ambition. It is interesting to see that Hornby's TT120 track already offers superior points when compared to their OO product...

 

[6991]

It's a good discussion point but.....
Many manufacturers actually specify a minimum recommended radius of track for their locos, most often the publicity for the locos illustrates this minimum radius too. So I reckon if it's stated on the box and you have tighter curves and you buy the loco and you have problems.........

Cheers,
6991
PS
We have had a perfect example of this in Sydney recently, service on one of the 'light rail' (tram) lines was withdrawn because the wagons (I believe from Spain) had developed nasty cracks in the bogies because the curves were too tight (most likely incorrectly specified). All the rolling stock was withdrawn for modification, after less than 5y in service - I am unsure of the current status.
In addition I'm not going all Gary Lineker, but when the tram fiasco is added to....
Ferries (from Indonesia) for the Parramatta run that do not fit under the bridges
Rolling stock (from Spain) that was too long for the tightly curved Blue Mountains line and scraped the platforms.
Ferries (from Korea) for the Manly run that cannot operate in even moderate conditions of swell near the Heads.
10 coach trains (I think from Korea) that are supposed to be driver only (no guard) and the driver cannot see the down length of the train for public safety.
Worst of all (sorry Greyvoices), they employed 250 of the finest public transport railway 'experts' to run our Sydney and NSW train network (from the UK !!!). As if...and can you imagine the cost ??
The transport minister that ordered all this stuff has resigned, but the Treasurer that paid for them all is now the NSW State Premier - appointed after the previous incumbent was caught out shagging a Country MP and diverting funds to their local projects, including a gun club !!
If it rings any bells for you blokes in the UK, it is the current conservative NSW Government - who continually criticise the Labour party for their fiscal misdemeanours (even though they haven't been in power for over a decade).

And Kris.. you said..
My view is then if it cannot handle R2 you are heading for commercial suicide.
But maybe this is wrong.....us old blokes keeping the economy afloat by spending our Super don't do R2 any more...and we want sound, bells, whistles, and synchronised smoke (not forgetting 'sprung buffers' - wtfbtw?)...

 

[6991]

Just following on... it's weird I know but can you imagine getting this around R2

.....nor can I !
It's a Rivarossi model of the Br 59 class 2-12-0 which lasted until the mid 1950's on DB (a bit later on the ÖBB)..

Cheers
6991

 

[dwb]

Interesting you should show a Red & Black.
I looked up a few of Roco's 4-6-2 and 2-10-0 tender and 2-10-2 tank locos yesterday to see what minimum radius was required. It was the 4-6-2s that had the larger requirement of 419mm which is R3. The others are all spec'd at 358mm which is R2. Roco don't have an R1.
I don't have any Roco steamers to see exactly what they look like when going round such right curves but my shelf layout has R2 and I've been surprised at how some rather long coaches have managed to get around them but return to very close coupled on the straight.

David

 

[6991]

Hi David,
The Roco tender locos of 60000 and 70000 (i.e. over the last 15 - 20y) series have cardan shafts from the tender to the driving wheels. This may be one reason for the increased minimum specified radius. I think Brawa specify minimum radius for their tender locos too.
The Rivarossi loco above has extra sideplay on the first and sixth coupled axles. It is a thing of beauty, as you can see.
Most European manufacturers have nailed the tight curve vs close coupling equation and their passenger rolling stock negotiates these bits with ease.
Cheers
6991

 

[Graham Plowman]

In response to the OP, I'm probably going to end up 'throwing a rock in the pool'.

I use the term 'you' as a general word, meaning 'everyone'.

Personally, I have never used set-track. My first ever turnout was a Peco large radius 'universal' left hander back in the early 1970's. I subsequently used Peco large radius 'Streamline' code 100 turnouts up to the late 90's when I moved to their code 75 equivalents which are still extant on my 'Ashprington Road' layout.

There is a trade-off between basic physics, realism and the demand/costs of addressing same.

Personally, I would be in favour of ALL radii under the radius of a Peco large radius turnout being scrapped. To me, all of those radii are nothing but toy-trainset curves and completely detract from any form of realism. How can you have 'better OO track' when you run pacifics around 2 foot radius curves with massive side-ways swing at the ends and 'leaps of faith' between coach gangways ?

I have a big issue with models being compromised to go around R2.

I also think that people need to get to grips with the reality of physics that trying to get large pacifics and 8 or 10 coupled locos around totally un-prototypical radii basically defies physics. If you want toy-trainset radius curves then the compromise you should be making is that you confine yourself to 0-4-0's and 0-6-0's. Or you use Hornby Railroad which is purposely designed for you, not me.
Why should I, with 5+ foot radius curves be required to compromise accuracy on my models just so that everyone else can get those same models around toy curves ?

But the reality is that I am in an extreme minority and manufacturers will always address the needs of the majority for obvious commercial reasons.

My 2 cents worth!

 

[kristopher1805]

That's fair enough Graham but as you say making models just for the few (you being one of those) is not a business, as is noted above as well German R2 is a bit tighter than British R2 possibly because of the HO scale leading to smaller models than the OO we are used to. That said it is not much different but the Germans seem to be able to cope with it.

Likely R3 would be a more generally acceptable standard but then might be impossible for some - hey you guys go buy a TT120 set and Mr. Kohler will be happy, for the rest of us readily using the existing dimensions we can as we expand get the bigger radius points and go on from there but if you only cater for those of us fortunate to have the space then how are you to have viable sales unless you make locos on the smaller end, coaches of the smaller size as well but in fairness Hornby have managed this for years, the Black 5 may be due to be replaced but it is still a good looking model - or good enough and tackles the likes of R2 and at the end of steam was the last thing to be seen!

So back to the conundrum and the new manufacturers, Heljan have done themselves no favours as their locos are supper picky, Sonic A5 has its issues as I note elsewhere but solvable and I am awaiting Accurascale Jones goods, perhaps they anticipate weak sales levels and little care but I think upon balance they would like to sell out production, so back to my point, if Hornby can do it then anyone else should manage as well and everyone is happy.

A word to the manufacturers - test, check, test again, recheck, test, test with poor track, test with or without dcc chips, test some more - the one thing I see again and again throughout society is the lack of testing by manufacturers, test with rubbish track, slightly bent joiners, test when the joiners are black with corrosion, test when track is dirty, test when the levels are all over the place, test on inclines, test rolling though a large number of varied points etc because it looks like you might never do any of this!

and er - please!

And here is W1 a lovely runner and the biggest non articulated loco you can buy in OO - got it right again Hornby!

http://imgur.com/WBspLI4

 

[kristopher1805]

PS wonder if I could make a 2-12-0 Robinson loco using the chassis from above a supper O4 with wide firebox he certainly contemplated two forms of 2-10-2 so might be a great looking loco? - love it 6991 thanks for posting.

 

[John Edge]

In answer to the OP, I believe that models should be made as accurately as possible without including all the prototype “foibles“ such as;
Limited clearance between flanges on coupled locomotives - some locos had wheels that are very close to each other and would demand ultra “fine scale” tolerances.
Ditto with valve gear and the like.
We do need our models to negotiate much sharper curves (and rougher track!) than the real thing but basing our needs on going around a Christmas tree is, frankly, ludicrous.

In short, I believe the entire hobby is literally, nothing to do with children anymore and should be sold as such.
Adult collectors followed by adult modellers are the major buyers - models today are certainly priced to reflect this so why continue the pretence this is a hobby for children?
By all means, continue to sell “railroad” as a beginners or child’s range but the high quality stuff is adults only!
Then market these models very specifically as such and forget about small radius track.

If a working model demands six foot radius then so be it but I’m sure most prototypes could be made to deal with five foot radius with little compromise. Four foot radius should be an absolute minimum.

 

[Graham Plowman]

In answer to the OP, I believe that models should be made as accurately as possible without including all the prototype “foibles“ such as;
Limited clearance between flanges on coupled locomotives - some locos had wheels that are very close to each other and would demand ultra “fine scale” tolerances.
Ditto with valve gear and the like.
We do need our models to negotiate much sharper curves (and rougher track!) than the real thing but basing our needs on going around a Christmas tree is, frankly, ludicrous.

In short, I believe the entire hobby is literally, nothing to do with children anymore and should be sold as such.
Adult collectors followed by adult modellers are the major buyers - models today are certainly priced to reflect this so why continue the pretence this is a hobby for children?
By all means, continue to sell “railroad” as a beginners or child’s range but the high quality stuff is adults only!
Then market these models very specifically as such and forget about small radius track.

If a working model demands six foot radius then so be it but I’m sure most prototypes could be made to deal with five foot radius with little compromise. Four foot radius should be an absolute minimum.

When we ran the annual Wishlist poll from 2006 to 2012 on https://modelrailways.online our observation over the time that we ran the poll was that the average age of people in the hobby was moving from 50's into 60's. 10 years on, it is probably 70's. That means the manufacturers are largely marketing to cashed-up older people.

That said, if we want the hobby to continue, we must support new entrants in the younger age groups and of course, Hornby has done this with Railroad.

When I was small in the 1970's, I had Hornby mark II coaches and a buffet car. Dad started purchasing Airfix mark IID coaches which were way better quality at the time. Airfix was seen as 'adults' models. Same as Mainline was. Hornby was for kids. These days, Hornby have understood this and worked out how to retain the 'adults' by manufacturing much better quality models (the Merchant Navy was the start of this) while still supplying the old 'Railroad' stuff.
So in a way, things haven't changed.

I agree that 4 foot should be the absolute minimum radius for 4mm scale.

 

[kristopher1805]

Well 4 foot is 1220 mm are you sure, so the minimum possible loop would need a board 2440 plus 40 plus about 60 so around 1320 mm, sorry Graham this is ridiculous Gotham curve was the sharpest on British Railways at 55 yards or converted to OO is 8.68 inches or 220 mm now OK this was unusual and makes R1 look like wide open spaces and latterly was worked by J94 type locos, Now in the main line railway the minimum curve seems to be 10 chains and 7 on freight lines or 3234 mm in OO.

So the whole thing is not so easy to work out and really Hornby and the others have come up with R1/2/3/4 etc because they can manage to get locos round this curve and it fits in a modest space, so if they want to sell models it has to fit tight spaces whether we are affluent pensioners reliving our youth wasting time along the lineside and hoping to recreate some of this heaven or whether we are looking at a fast lecky sort of things whizzing by, and in consequence are a rather younger set of persons we look to model what we see or recall.

Overall the manufacturers have got it right on balance and they can appeal to all markets and that is what we need, more sales keeps the prices lower and those that heavily discount (such as Heljan) are simply losing the ability to fund the next model - this is bad for us.

http://imgur.com/cVL2t9P

Struggles a lot due to long distance to the front bogie

 

[Graham Plowman]

Kris,

We covered curve radii in our article Cant and Transition Design on Model Railways Online, but to summarise, to be able to build a model railway at all we have to accept a very considerable compression of the prototype. The radii we use are very tight. Generally, six coupled mainline steam locomotives can only just get around a 90m radius curve, dead slow, with someone walking alongside to ensure the wheels don’t start to lift over the rails. In 4mm scale that is 3’-10½” radius. To meet the requirements of Her Majesty’s Inspectors, strictly speaking, any 4mm scale curve of less than 8’-6” radius should be fitted with a continuous check rail. At the other extreme the minimum radius around which our 4mm scale HST can run at 100 mph is 55 feet. With few exceptions model railways should have a scale speed limit of 15 mph with some parts as low as 5 mph.

I believe that Rx radii are:

R1 371mm, 14 5/8"
R2 438mm, 17 1/4"
R3 505mm, 19 7/8"

They are all way below the minimum 46 1/2" (approx 4 foot) required for a 6-coupled loco on a 90m prototype curve.
Even my 5 foot radius curves should have a continuous checkrail and be speed limited to 15mph!

If people want to run radii that are way off the bottom of the scale, that's up to them, but they need to realise that if they make that choice, it compromises any form of realism (unnecessary compromises to the models themselves, totally unrealistic end-swing, 'leap's of faith' between gangways etc) and puts them well in toy-train-set territory.

Personally, I prefer to aim for something a bit better.

PS: Not sure what the relevance of that loco pic is.

 

[34C]

...Struggles a lot due to long distance to the front bogie

...Not sure what the relevance of that loco pic is.

The relevance is that it is fairly typical of UK designs which are challenging for UK OO set track if overall made to scale, save for the OO compromise of having the gauge scaled at 3.5mm/ft.

To be positive, the present state of play in RTR OO is that by extensive borrowing of well proven HO technique, both for mechanism and exterior modelling, we now generally have accurately rendered exteriors on competent mechanisms. But we are now running up against prototypes which are from the 'awkward squad' which RTR brands have in the past largely either ignored, or if popular enough to be in strong demand, have seriously mangled the model's appearance to 'make it work'.

Back to the opening question: should the brand management make the customer aware that a product isn't suitable for set track operation, and if so, how should this be described?

I haven't 'got religion' in this matter; when young participated in EM and P4, and met quite sufficient 'true believers' then to last a lifetime. My perspective - and it appears to be broadly shared among the model railway purchasing public - is that OO is an acceptable compromise for RTR models; and here's the beauty of it, done well it can satisfy the customer base that exists: set track OO layout all the way to finescale OO, and provides significant material which EM and P4 modellers can use.

What I reckon is that RTR OO models from the 'awkward squad' can now be made without exterior compromise to appearance if a 30 inch minimum radius is accepted; with no problems for set track users if a set of compromises is accepted and applied as required: reduced wheel diameter, flangeless wheelsets, moving exterior body work to clear wheel and truck swings, absent detail. All of these are currently employed, so should come as no surprise. (For my own purposes I am able to make the stock look right by DIY modification, limiting models from the 'awkward squad' to 30" minimum radius, which is used in concealed locations. Out on the visible sections forget 4' minimum radius, on the running lines a scale mile is what I use for the right appearance of 'bombing round the curve' at full express speed.)

It's the selling of this that I am after. Something on the lines of 'Suitable for use as supplied on R2, when fully fitted with all user-optional parts requires a minimum radius of <as applicable to model>'.

The sensible minimum radius references would probably be best expressed by existing track pieces: R3, R4, 24", 30"; there's a switch from set track radii to inches where set track ends and the commonly available Peco streamline points begin.

A rider to the 'Suitable for use...' piece would be: User to determine what is achievable on their layout(s), because we don't possess a crystal ball enabling us to see layout designs or the standard of your track laying. (That's probably something only Rapido among current brands might go with, but I am sure a lounge lizard with the obligatory teflon suit can find more emollient ways of expressing the thought.)

 

[kristopher1805]

Yep, something along the same lines as my 4 track has the tightest radii as R3, R4, (571mm) R5,(639) R6 (705mm) - I think I got those rightish and uses Peco large radius points and that somewhere copes with everything as well, the code 83 curve I have ready to fit is R7 on the inside so I hope that smooths out the difficult locos I have on hand at a hard to get to place it does seem quite close to Code 100 but a wee bit smaller rail depth but I anticipate no problems with rail step up as it seems close enough so we'll see. So referring to 34c above 24" is 610mm, 30" is 742mm and I have used these with track setta's I suppose and anyway the temptation not to use smaller locos on the inner track would be a shame, such as the J11, various tank locos and the like, also the Q6 is happy here as are such useful locos as the Bachman austerity.

Now in fairness with this subject you can make a very decent layout with the Peco track plans book and also a very small one so my general belief is that the compromise works and most of us are happy.

http://imgur.com/Wd0b8Jv

My biggest loco is the Garrett but this goes around pretty much anything