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PECO Announces Bullhead Track for OO

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Most plank layouts are probably viewed from the side, and if they are at a certain height you cannot see the guage difference between OO and EM,P4 as you are looking side on.

 

That's what I'm doing for my next layout :sungum:

 

 

That's a view that Ian Rice elaborates on in his Mainlines in Modest Spaces book. It's certainly worth considering.

Edited by Anglian

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And for those with an interest in  further reading about scale & gauge, consider Iain Rice in his Chapter " An Historical Introduction" in his book Railway Modelling The Realistic Way

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My plain trackwork is SMP and my points are a mix of soldered construction and PECO code 75 flat bottom. 

 

I have a problem with a couple of LH PECO large radius electrofrog turnouts, especially in the straight ahead direction.  Basically, stock wheels seem to drop into the gap between the wing rail and the crossing vee,  with a bump on hitting the latter which can cause derailments.  This gap appears to be approx. 1 cm long and is smaller in smaller radius PECO points.  Plse have other users experienced this problem and is there a "fix"?

 

Do our track experts have an opinion whether the new PECO BH points may offer improved running?

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My plain trackwork is SMP and my points are a mix of soldered construction and PECO code 75 flat bottom. 

 

I have a problem with a couple of LH PECO large radius electrofrog turnouts, especially in the straight ahead direction.  Basically, stock wheels seem to drop into the gap between the wing rail and the crossing vee,  with a bump on hitting the latter which can cause derailments.  This gap appears to be approx. 1 cm long and is smaller in smaller radius PECO points.  Plse have other users experienced this problem and is there a "fix"?

 

Do our track experts have an opinion whether the new PECO BH points may offer improved running?

I've used CD75 Peco points on three layouts, any normal points are large radius, and I've never experienced what you're describing particularly running straight, more often derailments occur on the diverging route. It sounds more like a wheel profile or back to back measurement issue and that's where I'd start my investigation.

 

It is possible that you may have two faulty points, but I'd start with the wheels, and then look at the track laying to see if the point is twisted during or after tracklaying. I'm expecting the new pointwork to be as reliable if not better than the existing range.

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This problem requires more information:-

1. Does this happen with all wheels or just some and is it repeatable if the latter?

2. Have you checked back to back on any that repeatedly drop in?

3. Have you got any 'finescale' wheels installed, ie not OO, and if so are these the one's that drop in?

 

My suspicion is that when the wheels enter the curve the inside wheel back rubs the checkrail and the outside wheel successfully fords the gap across the shortest distance between the point rail and the frog nose. This suggests that the back to back is about right. However when taking the straight road the wheels are free to move from side to side within the constraints of the check rail and gravity drops the wheel into the gap with the other wheel flange hard up against the stock rail.

 

Opening up the back to back may help the straight ahead case but may cause the outer wheel to hit the frog nose when taking the curve....!

 

Unfortunately the clearances designed into OO can have these sort of problems and I suspect the BH points will be exactly the same.

Edited by Jeff Smith

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I have a problem with a couple of LH PECO large radius electrofrog turnouts, especially in the straight ahead direction.  Basically, stock wheels seem to drop into the gap between the wing rail and the crossing vee,  with a bump on hitting the latter which can cause derailments.  This gap appears to be approx. 1 cm long and is smaller in smaller radius PECO points.  Plse have other users experienced this problem and is there a "fix"?

 

Hi,

 

Changing the back-to-back is unlikely to make much difference to this. If wheels fall into crossing gaps there are two possible reasons, or both at once:

 

1. The wheels are too narrow. To run on Peco track wheels need to be at least 2.8mm wide. This limits you to RTR models -- kit wheels such as Markits, Alan Gibson, Ultrascale, etc. are narrowwer than 2.8 mm and will fall into the crossings with a bump, although not usually derail. There is nothing much you can do about this. And/or

 

2. The gap is too wide (not long). The flangeway gap on each side of the crossing vee should be no more than 1.3mm, or 1.4mm absolute maximum. You can check this with car spark-plug feeler gauges. If the gap is more than this you have a faulty product which ideally should be returned to Peco for replacement.

 

You may be able to improve matters by gluing thin shims to the wing rails.

 

regards,

 

Martin.

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Place a shim of plastikard in the grove in front of the 'V' or frog. This will support the wheel flange and stop it dropping, but of course you would need to standardize of RTR wheels to match your loco wheels. I did this with Peco 0 gauge points....

 

post-6680-0-82930200-1507230013_thumb.jpg

Edited by coachmann
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Place a shim of plastikard in the grove in front of the 'V' or frog. This will support the wheel flange and stop it dropping, but of course you would need to standardize of RTR wheels to match your loco wheels. I did this with Peco 0 gauge points....

 

attachicon.gifWEB frog support.jpg

I think this was standard practice  for RP25 type wheels  way back when .

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You can even solder rather than glue some metal shims to the wing rails if you're careful enough (I've tried it so I know it can be done), thus helping to maintain power supply to the wheels, but as has been stated you have to be able to standardize wheel dimensions sufficiently. Peco's "code 75" points incorporate wider flangeways than would normally be produced by hand building with a set of code 75 roller gauges. The Peco points thus accept a wider range of RTR wheel profiles and BTB settings, but they don't support the finest wheels through the crossings. You can't successfully run the same variety of unaltered RTR rolling stock if you narrow down the flangeways to make the finer wheels behave properly.....

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I've got unmodified Peco CD75 electrofrog points and a mix of RTR wheel profiles and Gibson/Maygib wheels and don't have any running problems though the crossings of the points. 99% of the rolling stock is rigid RTR/kitbuilt, with one or two items compensated. Any problems particularly with striking the Vee I've experienced have been sorted with adjustment of b2b or rarely a replacement wheel set.

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Perhaps we should all (brits,euros,americans) have adopted American OO scale that has  a track gauge of 19mm- very close to the P4 18.883- a nats whisker.

In an ideal world of course S gauge would be king......

The trouble is that it's a gnat's whisker in the wrong direction (P4 is 18.83 so the whisker of a slightly larger gnat)

 

There were several British workers who used 19mm gauge before and soon after the war, most notably Norman Mathews with his quite extensive outside third rail Southern Transport layout, It was seen as the "correct" gauge for 4mm/ft, which to the nearest half millimetre it was, and the BRMSB were under some pressure to adopt it for fine scale OO. In the end they opted for 18mm gauge based on a mathematical calculation of the reduction in gauge required for any model scale.

 

19mm OO was quite popular in N. America for a time - it's not really "American" OO scale as it was developed in Britain (any more than H0 is "foreign") but it's disadvantage was that you could simply get more layout into a given space with H0. If you "do the math" as Americans would say, you'll find that 8 cars in HO occupy the same length as 7 cars in OO .  It's possible that the development of small powerful 12V motors during the war helped remove OO's big advantage over HO in terms of cramming a mechanism into a model locomotive. I wonder too if the war had another effect with far more people trained in precison engineering and manufacturing so used to working to very fine tolerances. 

 

Interestingly, until the early 1950s, OO and H0 were being used rather interchangeably in France to refer to models running on 16.5mm gauge track - originally 1:86 taken by halving 1:43 scale plans- but then 1:87 scale.

It is rather ironic that most of the world uses a different scale for O gauge than we do, (though the French also use 1:43.5) yet the most popular scale almost everywhere except in Brtiain, was based on halving that scale. H0 (1:87) isn't half of German (1:45)  or American (1:48) O scale but it is half of British O scale.   

Edited by Pacific231G
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The  correct "back to back" gauge is pretty much dependent on the thickness of the wheels, and flanges in question - it is what some call the "check gauge" that matters - From the front of one flange to the rear of the other. But OO standards are a bit of a mishmash ;)

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HO seems to be working quite well here...

 

attachicon.gifpost-2677-0-99146100-1397672414.jpg

 

attachicon.gifpost-2677-0-22751200-1397672401.jpg

 

attachicon.gifpost-2677-0-41850100-1397672450.jpg

 

It's really quite startling to see the difference between 1/87 and 1/76.

 

Images from the lovely Longdrem and Pinkhill thread.

 It does indeed work fairly well there. The loco has RP28/88 wheels which scale to about 2mm wide. I wonder though, how many people would be prepared to pay the 1800 GBP that these currently sell for?

 

Regards,

 

Craig W

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It does indeed work fairly well there. The loco has RP28/88 wheels which scale to about 2mm wide

 

Which in fact don't work. Or at least, not on standard H0 track. They fall in the crossings with a bump.

 

Martin.

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I've got unmodified Peco CD75 electrofrog points and a mix of RTR wheel profiles and Gibson/Maygib wheels and don't have any running problems though the crossings of the points. 99% of the rolling stock is rigid RTR/kitbuilt, with one or two items compensated. Any problems particularly with striking the Vee I've experienced have been sorted with adjustment of b2b or rarely a replacement wheel set.

 

 

The  correct "back to back" gauge is pretty much dependent on the thickness of the wheels, and flanges in question - it is what some call the "check gauge" that matters - From the front of one flange to the rear of the other. But OO standards are a bit of a mishmash ;)

 

Agreed on all matters. I wasn't suggesting that wheel profiles and gauges have to be absolutely uniform in order to get what many would regard as acceptable running, but the range of variations has to be limited. Rigid chassis on well balanced models, as opposed to floppy compensated set-ups, also help to avoid the snag of wheel drop into crossing gaps. And yes, BTB uniformity alone is a nonsense if flange thicknesses vary.

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I have seen many British H0 models. A few years ago I saw a layout based on the ScR using Lima H0 class 33s converted to class 26 and class 27 and some super detailed Playcraft Class 21s, some even running as class 29s. H0 works. I wish I could recall what the layout was called, it looked great.

Hi Clive

 

I think this was Glasgow Emerald by Andrew Knights. Clever design on two levels with lots of urban atmosphere.

 

Max

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Perhaps we should all (brits,euros,americans) have adopted American OO scale that has  a track gauge of 19mm- very close to the P4 18.883- a nats whisker.

In an ideal world of course S gauge would be king......

The British Standards proposed this back in 1949 they wanted 4mm - 1' with 16.5mm Gauge to be called OO Course Scale, and 4mm - 1' with 19mm gauge to be called OO Fine Scale - never happened.

A starter for 10 - HO should be 17/128" - 1' on 5/8" Gauge rail, it was the industry that rounded it up to 16.5mm gauge and 3.5mm - 1'.

So endeth the History lesson. :read:

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The British Standards proposed this back in 1949 they wanted 4mm - 1' with 16.5mm Gauge to be called OO Course Scale, and 4mm - 1' with 19mm gauge to be called OO Fine Scale - never happened.

A starter for 10 - HO should be 17/128" - 1' on 5/8" Gauge rail, it was the industry that rounded it up to 16.5mm gauge and 3.5mm - 1'.

So endeth the History lesson. :read:

So down to Napoleon and metrication then? Which brings us back around to discussing dead frogs... :sclerosis:

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The British Standards proposed this back in 1949 they wanted 4mm - 1' with 16.5mm Gauge to be called OO Course Scale, and 4mm - 1' with 19mm gauge to be called OO Fine Scale - never happened.

A starter for 10 - HO should be 17/128" - 1' on 5/8" Gauge rail, it was the industry that rounded it up to 16.5mm gauge and 3.5mm - 1'.

So endeth the History lesson. :read:

Who really cares 

 

You have what you have either got EM or P4 if you dont like OO

 

So endeth the Reality lesson

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So down to Napoleon and metrication then? Which brings us back around to discussing dead frogs... :sclerosis:

[email protected]@dy French

 

PS: like the sound of 19mm gauge, would that be described as P45?

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The British Standards proposed this back in 1949 they wanted 4mm - 1' with 16.5mm Gauge to be called OO Course Scale, and 4mm - 1' with 19mm gauge to be called OO Fine Scale - never happened.

A starter for 10 - HO should be 17/128" - 1' on 5/8" Gauge rail, it was the industry that rounded it up to 16.5mm gauge and 3.5mm - 1'.

So endeth the History lesson. :read:

Not quite true Simon (and nothing Tim to do with the [email protected]@dy French who seem to have taken their lead in railway modelling from Britain)

 

The British Railway Modelling Standards Bureau did most of their work during the war when the suspension of model manufacturing seemed to provide an opportunity for a fresh start. From the start they decided, and it was controversial, that "Scale OO" would have a scale of 4mm (to the foot), a gauge of 18.0 mm and a rail height of 2.0mm (close to code 80) while "Standard OO" (they never called in Coarse) would be 4mm scale, 16.5mm gauge, with a 2.5mm rail height (almost identical to code 100)

 

The Bureau, really an ad hoc committee of four or five people, was chaired by J.N. Maskelyne the editor of Model Railway News and in the piece introducing its H0 and 00 standards in  April 1942  he says "The adoption of 18mm gauge for Scale "OO" is deliberate and intentional and was decided upon only after the possibilitiies of 19mm had been most carefully investigated. The latter figure is not impossible; but it is very slightly over-scale, and leads to difficulties with certain types of outside cylinder locomotives and some specific examples of British rolling-stock".

The Bureau made a similar and also criticised decision with O gauge by adopting 32mm rather than 33mm which would have been more scale accurate for 7mm/ft but would have required larger curves than the 5ft radius they felt to be practical .

 

Unlike the NMRA, who were also taking advantage of the wartime hiatus to establish and refine standards, the BRMSB standards were all expressed in millimetres. 

 

It's not terribly difficult to see why. Rulers marked off in cms and mm often combined with an inch scale were far more common in Britain than in America and it was far easier, even without a scale rule, to multiply a prototype dimensions given in feet by four (or seven in the case of O gauge) and mark it off in millimetres.A lot of early modellers also used 0 scale plans and reduced the dimensions by half which gave them 3.5mm/ft  I always reckon that a model scale expressed in mm/ft is a dead give away of its British origin as those developed in N.America (such as 1:48 O, 1:120 TT and of course S scale) tended to be expressed as fractions of an inch to the foot.

 

I have a copy of the first volume of Model Railways News from 1925 when O gauge was still considered small scale and 00 gauge was still in the hands of a few experimenters, long before anything was commercially available apart from tinplate trains from Bavaria. There was already an argument about whether the scale should be 4mm or 3.5mm/foot and that was almost invariably how they expressed it. In fact, most all the actual models that appeared that year were 3.5mm/ft but there was a strong lobby for 4mm/ft  The one exception is a description of a fairly large clockwork powered layout in 1/8" to the foot scale by a Rev. H.A.Turner who was adapting the German mechanisms and building his own track from wire.   

Edited by Pacific231G

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Hattons now have the bullhead points for preorder at £26.

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The British Standards proposed this back in 1949 they wanted 4mm - 1' with 16.5mm Gauge to be called OO Course Scale, and 4mm - 1' with 19mm gauge to be called OO Fine Scale - never happened.

A starter for 10 - HO should be 17/128" - 1' on 5/8" Gauge rail, it was the industry that rounded it up to 16.5mm gauge and 3.5mm - 1'.

So endeth the History lesson. :read:

I've posted this link before, but for those who have not seen it

http://www.doubleogauge.com/history/history.htm

The second page is probably the most relevant to this discussion, though the issue of width over wheels and splashers and a possible reason for the increase from 16mm gauge to 16.5mm gauge are mentioned on page 1

Edited by JeremyC

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I've posted this link before, but for those who have not seen it

http://www.doubleogauge.com/history/history.htm

The second page is probably the most relevant to this discussion, though the issue of width over wheels and splashers and a possible reason for the increase from 16mm gauge to 16.5mm gauge are mentioned on page 1

All three of Stephen Siddle's articles are well worth reading and he's made an excellent study of the hobby's history as recorded in its magazines. I would though quibbble with a few points.

 

I believe that Henry Greenly was more responsible for the 4mm scale ,16.5 mm gauge, situation than Stephen suggests. As the effective founder  of the hobby he gave respectability to the compromise and was backed in that by the Model Railway Club which he'd more or less founded. Going right back to Greenly's own pre Great War magzine Models, Railways and Locomotives it's clear that, once he had determined what a standard should be, he considered it to be "settled for once and for all" so he championed 4mm/ft vigorously and argued furiously against anyone, such as A.R.Walkley with the temerity to suggest using the correct scale. There was a slightly amusing exchange in  MRN in 1925 when Stuart-Reidpath presented a "00" coach scaled at 3.5mm/ft. Greenly immediately claimed that it was seriously "underbodied" (i.e. the body was too small) and practically ordered Stuart-Reidpath to give its dimensions. He did and, needless to say, it was a very accurate scale model.

 

Stephen also repeats the myth that "foreign" steam locos don't have splashers so their wheels can be over wide with impunity. Many don't but many others do, including a lot of passenger locos that are deservedly popular as models. The first convention of national model railway associations in the early 1950s (that led to MOROP and the European NEM standards) actually saw off an attempt to saddle  European H0 with a similar compromise of 1:80 scale using 16.5mm gauge that did get built into some proprietary "H0" models.  

 

Those points aside, it's a very good and well documented account of the development of our hobby. The turning away from the contemporary railway in the 1960s is well noted and something I can certainly remember. That didn't happen in the rest of Europe, probably because railways didn't appear to be in terminal decline while in most countries steam's twilight was more an orderly retreat than the massacre it felt like here.   

Edited by Pacific231G
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