Model Railway Forum banner
1 - 19 of 19 Posts

· In depth idiot
Joined
·
8,691 Posts
Discussion Starter · #1 ·
Talking regular RTR OO here, on any 16.5mm gauge track system.

I was very pleased when I first bought a Heljan diesel model to see that they were using a significantly shallower flange on the wheelsets than is normal for RTR OO. The trackholding was not affected, the models stayed on the rails; on a mixture of Peco's streamline codes 100 and 75, and code 75 SMP BH track and points, and soldered construction points, smallest plain track radius 24", smallest radius point 36". (Although I have no set track, it was at the time possible to try these models on a friend's set track layout - all purchased from circa 2010 - and they were trouble free if operated at modest pace through the points, no problems on plain track curves.)

Even the two Heljan steam locos I have (O2 2-8-0) tempt fate by offering the shallower flange on a rigid 8 coupled chassis, yet perform perfectly on track.

Some Accurascale and Hattons wagons have recently come my way, and these too have shallower than normal flanges, very good too.

So, is there any objection to a shallower flange becoming general in RTR OO?

I like it for the benefit to appearance, and it would be handy on a few UK steamers which have their wheels closely grouped and are necessarily 'dimensionally massaged' to make a practical running mechanism, because the normal flange depth fouls (e.g. C1, H1, H2, atlantics, Peppercorn A2 pacific, BR std 9F). There may well be more such, these are the examples I know; I'll be particularly interested to see how Hornby handle the problem on their all new tooling 9F: the present RTR models are both 'massaged', Hornby, correct overall coupled wheelbase length, but axle centre spacings varied, Bachmann, axle spacings consistent but slightly overscale, resulting in an overall coupled wheelbase 2mm over scale.
 

· Administrator
Joined
·
10,720 Posts
Whenever 'finer' wheel standards get mentioned, I automatically think 'RP25' which is an NMRA standard https://www.nmra.org/sites/default/files/standards/sandrp/pdf/RP-25 2009.07.pdf

Sometimes manufacturers' model details will reference RP25, sometimes not. The spec for Accurascale cement wagons mention RP25.110 - https://accurascale.co.uk/collections/wagons/products/vtg-castle-cement-r Perhaps other wagons also have RP25.110 wheels as well even if the spec doesn't mention it.

Finer wheel flanges do look better than the 'pizza cutters' you find on some stock but your track laying needs to be up to it as well.

David
 

· Registered
Joined
·
2,767 Posts
All British outline manufacturers have been using finer flanges on their metal wheels since around 2000.

The days of 'pizza cutter' flanges were associated with Lima and they were an earlier phenomenon which changed in the mid 80's: Lima Wheels - Model Railways On-Line

The later Lima flanges were still large by today's standards but they were an 'improvement' on the earlier flanges.

When my son was small, we purchased the ubiquitous Thomas the Tank set for him. Even in those days, the flanges on the loco were good, but the loco and rolling stock kept coming off the track.
And this is the crux of the issue: if people are going to run these finer flanges on toy trainset 10 inch radius SetTrack curves, don't expect the stock to stay on the rails.
When Thomas ran on Ashprington Road with 5 foot minimum radius curves, he ran perfectly and never derailed. As @dwb correctly noted, track laying standards need to be up to scratch as well.
 

· In depth idiot
Joined
·
8,691 Posts
Discussion Starter · #5 · (Edited)
You will have noticed I didn't quote any dimensions or RP's.

Now, the usual choice of RTR OO manufacturers is some interpretation of RP25-110, which corresponds fairly well to the tyre and flange profile of kit wheels over the years from Jackson, MGW, Gibson, et al. This works, but the flange is around 1mm depth from root to flange tip.

What Heljan have done on their OO product (since I first saw it) is much the same tyre and flange profile, but the flange circa 0.6mm depth. This looks much better, and there's no problem on track. My recent first exposure to Accurascale and Hattons wagons, revealed that they have adopted this practise.

We are up against the chronic weakness of RTR OO that there simply isn't any standard worth the name to describe this, unless someone here knows different?

Whatever, I want more of this. Personal whittling of wheelsets has me convinced that yet better is possible on Peco streamline or better track if the following is observed:
... flange width and toe and tyre angle is far more important than the flange depth, so I’m with you…make’em shallower.
Further comments?
 

· Registered
Joined
·
240 Posts
Only to mention (yet again) that here in the States we have benefited from the above NMRA standards for decades. Because of this, the only issue I ever had came from trying to run German pizza-cutter wheeled stock on rail smaller than code 83...and 83 is smaller and looks better (to me anyway) than the code 100 I first started with, back in 1970.

Yes, all HO and OO should follow those standards...my opinion. :)

Mark in Oregon
 

· Registered
Joined
·
2,767 Posts
Only to mention (yet again) that here in the States we have benefited from the above NMRA standards for decades. Because of this, the only issue I ever had came from trying to run German pizza-cutter wheeled stock on rail smaller than code 83...and 83 is smaller and looks better (to me anyway) than the code 100 I first started with, back in 1970.

Yes, all HO and OO should follow those standards...my opinion. :)

Mark in Oregon
Be aware that the NMRA standards are applicable to US HO outline.
I am aware that several UK outline manufacturers use an interpretation of the NMRA standards, but the UK had standards way back in the 60's and 70's in the form of BRMSB. I believe that the like of Romford and all the other non-RTR manufacturers used to work to BRMSB standards.

But on the topic of standards, agreed, scale-appropriate standards should be followed. Please, not measurements made up by an individual (they are not 'standards') like OO-SF !!!
 

· Registered
Joined
·
240 Posts
"Be aware that NMRA standards are applicable to US HO outline".

Yes, but it doesn't matter what "outline" the model is (US,UK, whatever) if the track gauge is the same, correct? It would appear that by moving towards a smaller flange, the model makers are becoming more "in line" with those NMRA standards... which means that regardless of where you are, or what you run, everything would be interchangeable. A very good thing, in my estimation. :)

Mark in Oregon
 

· Registered
Joined
·
2,767 Posts
Personally, I am of the view that the 'baseline' standard for wheel and flange design of models should be that of the applicable prototype jurisdiction. Presumably, NMRA standards align with American prototypes ?
Thin flanges does not necessarily equal NMRA standards, for example, there are others such as the P4 standards in the UK and the Europeans have their own standards too.
As a modeller of the Western Region of British Rail in Devon, set in the 1960's and early 1980's, I am not aware that I need to have wheel/track standards that make my rolling stock 'interchangeable' with any prototype that didn't run in the area - for a start, the loading gauge and kinematic envelope would be different.
 

· Registered
Joined
·
240 Posts
I absolutely see what you're saying, and agree. If that's someone's approach, that's great. I love looking at pictures of layouts based on a particular era, location, etc. :)

I guess my point was that if I want to run trains of any prototype, it's great if they conform to some sort of standard so tracking is not an issue.

Mark in Oregon
 

· In depth idiot
Joined
·
8,691 Posts
Discussion Starter · #11 ·
Take a look at the P2 running gear shown in close up in this Hornby bulletin.
This loco is a problem child for RTR because the nominal 6'2" diameter over tyre driving wheels are spaced at 6'6" axle centres. It looks to me that Hornby are 'going for it', correct axle spacings, tyre diameter slightly less than 'new', flanges about half the depth they usually use, barely clearing those of the adjacent wheelset. We will only know with the model in our hands, but it looks good to me.
 

· Premium Member
Joined
·
6,577 Posts
I noticed when the Hornby programme was on that they used Hornby track exclusively for testing at Margate now mostly R3 and R4 but with R2 points. (somehow they never used the inner loops R1 and R2) Now I found the front bogie wheels on the A2/2 Thane of Fife a quite new loco had wide wheel flanges but quite shallow ones no pizza cutters are these, naturally I use 100% Peco code 100 streamline track and the A2/2 was very unhappy and came off the track all over the place, I have few sharp radius curves and all the main line points are streamline.

So I looked at the frog width and although I have not measured this the gap between frog and rail on the Hornby track but it looks to be wider than it is on Streamline, the same situation applies to the Heljan pony trucks (some of), so Peco needs a narrower flange but the depth can be reduced. So I rather think Hornby made wheels to suit their own track and did not take into consideration that most bigger layout owners are mostly Peco users but there are also other brands as well.

So my latest Hornby is the W1 and this behaves flawlessly on my track in contrast to the A2/2, I substituted some old Wrenn wheels with pizza cutter profile on the P2/2 and again the loco was transformed from a dog to a pedigree race horse, now I'll try the spare wheels for the back of the W1 might just be appropriate for the A2/2 as the Wrenn wheels do not look right, I just thought of this so I'll have a go over the weekend
 

· In depth idiot
Joined
·
8,691 Posts
Discussion Starter · #13 ·
I noticed when the Hornby programme was on that they used Hornby track exclusively for testing at Margate now mostly R3 and R4 but with R2 points...
Which is of course the correct thing to do when offering a 'complete system' ; it's all got to work together. (But I don't recall seeing their curved and 'express points' in that test track. Did you see any?)

And regarding the R2 point, a couple of retailers I regard as trustworthy have told me independently that the large majority of their customer's layouts still had these in use. That could be anything from the only type of point on the layout, to only in the storage sidings; but where they are used doesn't matter, fact is they are on most layouts. So it is imperative that everything works on the R2 point in any combination, the most stressful of which is a ladder of crossovers between multiple parallel tracks, which that test track had.

But there was something I definitely didn't see - but then I have only watched the Hornby two episode promotional aired some years ago, in one of which was the row between Hornby and 'Son of Hedley' (RoS) and the then MD of Hattons 'representing' for the model railway retailers.

What I didn't see was long trains in use for test purposes, which I would have hoped for. Can the new wonder loco push and pull a full size trainload whichever end is coupled on? Will the loco and train stay on the track pushing and pulling through the turnout ladder? I'd be thinking 15 coaches or 60 wagons as a useful test load for larger steam models and BR 1960's diesels. I bet Hornby don't, because they happily produce locos which simply spin their wheels with such a load, which in reality the protoype locos dragged around all day.

...So I rather think Hornby made wheels to suit their own track and did not take into consideration that most bigger layout owners are mostly Peco users but there are also other brands as well...
This requires insider information. Whatever Hornby's customer facing position (I read it as 'Hornby alone are RTR OO model railways') the likelihood is that there will be communication with Peco, because it is in their interest that their product operates well on the principal alternative superior track supplier's range. I wouldn't be remotely surprised to learn that Peco are regularly sent advance specimens of Hornby's new productions to operate on their test layouts.
 

· Premium Member
Joined
·
720 Posts
The conspiracy theorist in me says that Hornby have a room in that large ex factory with foreign track for testing purposes . I'd very surprised it if they left it to another company to check there own products.
 

· In depth idiot
Joined
·
8,691 Posts
Discussion Starter · #15 ·
Your hidden 'foreign test track' scenario, is very likely. I would have such a thing in Hornby's shoes, strictly for internal use.

But there is nothing quite like having another 'friendly and trustworthy' peer brand with whom you share an overwhelming common interest - flogging containerloads of product in the same market sector; which many times outweighs the modest competitive overlap - take a look at what is coming. A great many businesses do this routinely, because both parties stand to obtain useful knowledge about how their products work together.
 

· Premium Member
Joined
·
6,577 Posts
I do not see a smaller flange making any material cost benefit, the difference is tiny

Looking back above to 34c comments, I agree I never saw on any of the films a Y point, an express point (which in my view is weak on the plastic sleepers) any cross over nor the curved point which is a real dud in my view especially going in the sharp end and taking the inner track - derail! - as to foreign track none of that either but it does seem with the A2/2 they only made the bogie wheels to suit Hornby but have a sharper slightly deeper profile for the W1 which is why it runs so very well, now I wonder what Heljan use to test their products probably some German setrack say Flieschman, Profi I used some of this back along even then the setrack curved point was not very good if better than the Hornby and by the way I did not think much of the Peco version (although the streamline is very good) I also tried Bachmann but that was much of a sameness, OK going in the blunt end but not the other way at least with a sophisticated model.

I also think that although a load was 39 plus van a 60 wagon train would be a disaster going backward and something with lots of coaches would also be too much bother but certainly 20 wagons and 6 coaches or 7 bogie vans would be a fair test as few have longer trains than this.

So something happened in that the A2/2 was too radical and the W1 was corrected so at least Hornby might have done some product evaluation, the other issue here is what the Chinese manufacturers do, if they make a mistake it is likely they just send the product over here rather than scrap thousands of wrongly made wheels and this I think is the most likely scenario. I think we need a mole in Margate just sad I live near to Exeter.
 

· Premium Member
Joined
·
6,577 Posts
Graham I suspect the Bo-Bo or Co-Co format really helps the derailments come from in particular front pony trucks or bogies, training ones less of a problem as would be expected a 1Co-Co1 might show up with something different, the front bogie has a little load, small wheels with small flanges so it is a much more sensitive problem and it needs to cope with transitional gradients as well, the nearest thing I have are the Bachman Double Fairlees and they are really excellent.
 
1 - 19 of 19 Posts
Top