Back to Back Gauge

[darren01]

HI

Can any one help me with this ,i have a Hornby West country that do's not like my code 75 points .

The lcoo keeps ridding over the pionts and some times derails .

It lookes like the back to back gauge is out on it's wheels,i have brought a back to back gauge from C+L 00 set at 14.8mm.

As i am using code 75 track what is the right gauge ,as the 14.8 seems a little bit to big?.

This is the back to back gauge i brought;

 

4BBOO Back-to-back gauge - OO - 14.8mm

 

What i would like to know what is the right back to back measurement for my west country

All the best

Darren

[gordon s]

I use 14.4mm as a standard measurement for all my stock and locos and they run through my own 00 turnouts without problem. This corresponds to the DOGA Intermediate Standard.

 

http://www.doubleoga.../ctrackstd1.pdf

 

http://www.doubleogauge.com/standards/commercialwheels.htm

[bertiedog]

I am going to get flack from DOGA , but the normal (from 1948) is 14.55, usually taken as 14.5 as used by UK wheel makers and the NMRA for 16.5 mm track.

 

Easing to 14.4 only really helps older courser flanged designs to run and is letting the current makers off the hook on accuracy.

 

If the wheels have a profile and flange width like the NMRA, or the Meta type in the UK then 14.5 is best to aim for.

 

14.8 has been used for so called finescale versions, as usual the UK is plagued by these variations on a theme, and 14.8 is strictly for use with finer than RP25 flange widths.

 

The whole idea of standards is consistency, and we have a baseline 16.5 mm track, and only one back to back should be used and only one standard of wheel.

 

But we have a real world situation and 14.4 could be seen as a compromise, but as an engineer this reduces me to utter despair as to why people fiddle with this issue as it was settled 60 years ago in HO/00 16.5, and yet here we are confusing and mystified in the UK adjusting the track to suit very badly made wheels from major makers who should frankly know better.

 

Lets name names and send the Hornby back to Margate and ask them to fit usable acceptable internationally standardised wheels that run on 16.5 track!!!

[96701]

Well said, that man.

[bertiedog]

By the way this does not apply to Model rail experts who know the game, and can build to other standards, there is absolutely nothing to stop them, there is the finescale HO movement in the US which is promoting finer than basic NMRA , but these are savvy died in the wool enthusiasts, they know exactly what they are doing, there are makers who support them.

 

The same applies in the UK with finescale 16.5 , which C&L supply track for, and use 14.8 as back to back, but if you are following this finescale 16.5 mm course, you have to adopt the whole package, you cannot mix normal and fine together so easily..

 

The dreadful situation in the UK is "The man in the street" cannot rely on makers to provide the basic 16.5 based products that all work first time, whatever the make, from the box. He may not be an expert, he does not want finer scale, the standard product is all right, but we do not get the standard product.

 

Bachmann, Dapol, Vi, Heljan, Hornby, etc., should all have absolutely identical wheels, same flange width, tyre width cone and root, and same back to back. Plainly, they do not at present, very near but not a match.

[Allegheny1600]

 

Bachmann, Dapol, Vi, Heljan, Hornby, etc., should all have absolutely identical wheels, same flange width, tyre width cone and root, and same back to back. Plainly, they do not at present, very near but not a match.

 

I could not agree more, this is why i envy the (N/)Americans with their NMRA and it's standards!

Years ago, the NMRA set standards down for the US manufacturers to follow (voluntarily) and one after the other, they all did. Now you just KNOW that when you buy a US loco from maker A, it will couple up to maker B's loco (running in the same direction!), coupled to maker C's train negotiating maker D, E & F's track, powered by maker G's controller.

ALL the standards have been set down by the NMRA and therefore, everything is compatable AND uniform.

Now, compare that situation with the UK (and also Europe!).

While we really only have one track manufacturer, we do still have multiple wheel standards and wheel manufacturing standards and quite frankly, it's not good enough!

Why though?

We had DOGA, we could have had NMRA and we sort of, have NEM!

Simple!

IMHO, the British market is not strong enough to DEMAND the standard required, nor is it willing to pay for that standard (or has not been!).

Some people are, of course and will pay out for new wheels, track and so on (the finescale brigade!) but there is simply not enough of them to make the neccesary loud noises and quantity purchases (or withhold!) to make the difference.

I believe that if you want to make a difference - you MUST examine before buying. If not completely happy, don't buy it.

If distance buying, examine upon receipt and reject if not satisfied.

I once (not too long ago) went through all of the 6 examples of an 0-6-0 pannier tank in my local shop and still didn't get one to my satisfaction, no sale was made even though i wanted that model. I still have not got one!

Thats what we've got to do, people.

I'm sorry if that's harsh but until we all can do that, then we'll have to keep accepting inferior standards.

John E.

[darren01]

HI 6026

I agree with you in what you have said, when i looked on the net for a back to back gauge i even found that they all had diffrent sizes !,and they where all for 00!.

All i want to do is get my west country running as it should , when i brought the loco it ran up and down in the shop just fine , so i throught that i had a good loco here.

It was not untill i got home with it that i found out about the back to back being out.

So what size should i set the wheels at as it is very confusing as i have been told 14.4-16.5mm

All the best

Darren

[Allegheny1600]

Hi Darren,

My most sincere apologies! I got so involved in abusing the current state of the British market, i completely forgot to address your query! Sometimes known as highjacking the thread!

Anyway,

What you need will be as, mentioned in previous posts, the "double 0" gauge B2B (Back 2 Back!). NOT the "00 finescale" version!*

This should be 14.55mm but i believe will actually be 14.5mm!

Be sure the plastic inserts for the spokes don't interfere with the readings and make sure the wheel tyres are firmly ON the wheel (inserts).

Try and make sure each wheel runs true and is mounted perpendicular to the axle.

Also, make sure that all your other stock negotiates your points and trackwork okay - if not, maybe a track problem too?

Hope This Helps,

John E.

 

*Although the Peco code 75 track can be thought of as "finescale" - it is not! The only thing "fine" about it is the rail section, admittedly better tthan code 100. However, all the flangeways, check & wing rails are set up as per code 100 "standards", D'oh!

For reference;

Ordinary 00 RTR track needs 00 B2B (14.5mm),

00 Fine (handbuilt) needs 14.8mm B2B

EM (handbuilt) needs 16.5mm B2B..............WHAT!!!!! Just a coincidence! - The same measurement as 00 track - confusing or what! oo-er missus!

Cheers,

J.

[darren01]

HI 6026

So i need to set it for 14.5mm ,do you know where i can get a back to back gauge for this size,looks like the one from C+L is a no go ,being 14.8mm !.

All the best

Darren

[Ron Solly]

Try this site

http://www.doubleogauge.com/shop.htm & for dimensions http://www.doubleogauge.com/standards/index.htm

[gordon s]

Try this site

http://www.doubleogauge.com/shop.htm & for dimensions http://www.doubleoga...dards/index.htm

 

.....Ah, but it now seems we've gone full circle as the Standards you are referring to are the ones I linked to in my first post. No wonder we're all confused as they show the B2B as 14.4mm.

 

What chance has the new/average modeller got when the info put out by the DOGA is debateable.

 

If it helps, the Markits B2B gauge is listed as 14.5mm. (Page 17)

 

http://www.btinternet.com/~markits/cat_april_2009_v2.pdf

[Ron Solly]

Gordon, yes possible confusion as DOGA is 14.4 = or - .05mm.

I use 14.6 on Peco Code 75 & handmade points & adjust all of my stock ( Hornby, Heljan, Bachmann locos & passenger/goods stock) to suit.

Even USA locos like Athearn & Proto diesels & Bachmann 0n30 locos have no problems going thru my handmade 3 way points.

[Kenton]

Bachmann, Dapol, Vi, Heljan, Hornby, etc., should all have absolutely identical wheels, same flange width, tyre width cone and root, and same back to back. Plainly, they do not at present, very near but not a match.

I guess this all comes down to tolerances. I suspect that the specifications set by all manufacturers is to the same or very close (Hornby possibly based on Hornby track rather than Peco) but it is the tolerances in manufacturing that enable the odd one through (and insufficient Quality Control) Let's be fair, the majority of offerings do work straight out of the box when run on perfectly laid track.

 

What chance has the new/average modeller got when the info put out by the DOGA is debatable.

Quite possibly the new/average modeller has never heard about DOGA or simply couldn't give a d@¬ about them ? See in them yet another opinion on the never ending gauge war. About as relevant as EMGS or P4 or even S7 !

 

 

All too often we blame B2B when the track laying should be first examined, especially when a single point appears to be the location of a problem. Has the point been laid flat; have the toes been pulled apart by the following curves; if in a crossing - is it geometrically true; is the heel preceded by a sharp curve, any curve; has someone hammered one/several of those abominable track pins through the sleepers distorting the track?

 

14.4 14.5 14.6 ... I'm not sure it makes any difference - is the track that fussy - (14.8 is too big for the reasons explained above - it is for the esoteric OOSF not OO)

In OO a B2B gauge really is not required just adjust the odd wheel until it works or use a caliper. I've managed for all my years of modelling without one (I have one for EM - long out of use)

[Taz]

This is an interesting situation which I also find myself pondering about.

 

All the points on my scenic area will be hand built and I have recently aquired all the C&L and Exactoscale components I will need for this, including C&L roller gauges and b2b gauge. These are set to14.8mm b2b.

I will only have one peco point in my off stage area (I am using a traverser).

So far I have been concentrating my meagre modelling time on laying the track on the traverser. To test my track laying as I go I have two test trains - 1 Bachmann Mk1 rake and 1 freight train consisting of a mix of 4w stock.

I have opened up the b2b on these to 14.8mm using the C&L gauge. This wasn't as straight forward as I'd hoped with several of the Mk1's developing an anoying squeel since I have done this and Bachman's standard 4w fitted underframe needing some plastic filed away to take wheelsets with the increased b2b.

None of this stock has any problem with my single peco small radius point.

 

Question is, should I persist with the rest of my stock or will 'as supplied' RTR b2b work fine on handbuilt turnouts constructed with C&L roller gauges? Or should I look at an alternative source of gauges? I think some experimentation will be required once I move onto turnout construction.

 

I am prepared to modify all my b2b if necessary but it would be a shame if that meant my stock wouldn't work on other peoples layouts or their 'standard' stock on mine.

[gordon s]

Question is, should I persist with the rest of my stock or will 'as supplied' RTR b2b work fine on handbuilt turnouts constructed with C&L roller gauges? Or should I look at an alternative source of gauges? I think some experimentation will be required once I move onto turnout construction.

 

If they are the C & L gauges with 1mm flangeways, that would give a distance between check rails of 14.5mm, so any RTR stock with a B2B below that will bind or try to ride over any turnouts built with those gauges. I chose to use 1.2mm flangeways to reduce the distance between check rails to 14.1mm, so that any RTR stock will run through without problem.

 

If you want to use 1mm flangeways then it is probable that most RTR stock will need some B2B adjustment.

[Il Grifone]

If they are the C & L gauges with 1mm flangeways, that would give a distance between check rails of 14.5mm, so any RTR stock with a B2B below that will bind or try to ride over any turnouts built with those gauges. I chose to use 1.2mm flangeways to reduce the distance between check rails to 14.1mm, so that any RTR stock will run through without problem.

 

If you want to use 1mm flangeways then it is probable that most RTR stock will need some B2B adjustment.

 

 

R-T-R stock requires (obviously) flanges of less than 1mm to pass through 1mm flangeways. Luckily this is the case for almost all wheels made since 1970. (Dublo are a borderline case - most will some won't.) However setting flangeways to 1mm means the B-B has to be greater than 14.5mm. (Ignoring track and wheel tolerances which complicate matters.) This means than all wheels need resetting and the result will not then be 100 % compatible with commercial track, which is rather sloppy tolerance wise. (No names!) The alternative is to narrow the track gauge to 16.2mm (00-SF standards), which allows R-T-R to run without modification (beyond setting the B-B to 14.5*). For further information see the NMRA, DOGA and 00-SF websites - also NEM, but a knowledge of French or German is helpful here.

 

* Strictly this is only correct for 0.5 mm thick flanges. The important dimension is the check gauge the B-B plus the thickness of the flange which should be 15.00 - 15.2mm (BRMSB (Hornby) standards - NMRA allow a bit more but have a nominally thicker flange). Fine wheels (2.2mm thick) need the B-B set to 14.8 for this reason

 

Don't bother with a B-B gauge, buy a vernier caliper and use that for all your measuring.

 

I just checked a few wheelsets at random, from ancient BRMSB through HD/Wrenn, Lima to Hornby. All in the range 0.5-0.9mm so OK for 1mm flangeways, though the nylon HD wheels would have problems as their B-B is 14mm.

 

This subject has been discussed at length in the past.

[bertiedog]

Simply get a set of Vernier callipers and measure the Back to back to suit the track you have, but it should be 14.55mm, (usually taken as 14.5), unless you know what you are adjusting it for. Other standards exist for a multitude of reasons, it's all horses for courses, but the most flexible measure and gauge is the calliper.

From about £4.00 on ebay

Stephen.

[ozzyo]

HI 6026

So i need to set it for 14.5mm ,do you know where i can get a back to back gauge for this size,looks like the one from C+L is a no go ,being 14.8mm !.

All the best

Darren

 

Darren,

 

have a word with Mr. Lewis at C&L and see if he or does a 14.5mm B2B gauge in exchange for the one he soled you. He may be able to help you. If this has been mentioned before sorry.

 

OzzyO.

[Taz]

If they are the C & L gauges with 1mm flangeways, that would give a distance between check rails of 14.5mm, so any RTR stock with a B2B below that will bind or try to ride over any turnouts built with those gauges. I chose to use 1.2mm flangeways to reduce the distance between check rails to 14.1mm, so that any RTR stock will run through without problem.

 

If you want to use 1mm flangeways then it is probable that most RTR stock will need some B2B adjustment.

 

Gordon,

 

My personnal plan is to follow the Normon Solomon school of turnout construction and he advises using a U shaped jig made out of three pieces of copper clad sleeper to set the check rail spacings. So that would give a spacing of 1.06mm. Norman tests his work with a test bogie with one wheelset set at 14.8mm b2b and one at 14.5mm b2b. So i think I will try and get hold of a 14.5mm b2b gauge and that will become my minimum to work from.

I have been following your layout thread and your trackwork looks mighty impresive and fine, even with the 1.2mm check rail spacings (mind you, whats .2mm between friends )

[shortliner]

Not sure if we are talking about the same thing here but US wheelsets will work quite happily with PECO Setrack turnouts, but do NOT like Hornby Setrack turnouts one little bit as they come, derailing stock with monotounous regularity as soon as they are set for the diverging road. The cure is simple, wrap and superglue a strip of 0.005" phosphor Bronze strip (Squires - note other suppliers are available) around the guard/check rail si that it lies between the guard/check rail and the running rail - it just provides enough extra movement to pull the wheelset across and avoid the wheel flange catching on the point of the frog.

[craigwelsh]

14.8 has been used for so called finescale versions, as usual the UK is plagued by these variations on a theme, and 14.8 is strictly for use with finer than RP25 flange widths.

RP25 refers to a range of standard flange widths though, the usual one quoted is RP25-110 with RP25-88 the finer one people use a lot with finescale 00.

 

 

Darren get the one from Markits if you want one that should work but be careful not to muck up the quartering or you'll get rubbish running on the straight too.. If you aren't confident ask the shop to look at or replace it. As Kenton says you shouldn't really need a B2Bin normal 00 which is why people like C+L only sell finescale ones. Having said that though if it is out its better to use the correct tool than trying to guess which axle is out as you can be there forever making it worse!

[bertiedog]

I was not referring to NMRA wheelsets that use thinner flanges, but UK finescale ones that do, and would therefore be narrower than normal RP-25, (in comparison), which uses 14.55 as back to back. I am fully aware of all the variants, but mentioning them all confuses even more, the accepted US standard is 16.5/14.55.

 

My own position is that the existing HO, and therefore the identical 00 gauge, use NMRA profile limits, normally refered to as RP25, (but now altered in NMRA parlance, but effectively the same). This is the same profile used in 1948 onwards on compliant items, and remains in force.

 

It has ensured generations of users in the States delightful compatibility, whilst here in the UK, starting with the same base track, we have ended up in confusion, because of the actions of the toy trade makers.

 

One company has shone out in all of this and that is Peco whose herculean efforts to provide track and points for the multitude of UK and Euro wheel standards is often overlooked, they deserve a vote of thanks.

 

Stephen.

[two tone green]

Have a look at these

 

http://www.dccconcepts.com/index_files/DCCgaugetracktool.htm#BTB gauges

 

and I think Bromsgrove Models are due some soon.

[Enterprisingwestern]

Of course you could alternatively buy a GW Models adjustable b-b gauge, set it at a dimension which allows your stock to go through the pointwork, be it 14.3, 14.55 or whatever, then set everything else to that same figure.

The greatest advantage of this is that when you finally see the light and go EM or P4 you can still use the same gauge.

Simples.

[Enterprisingwestern]

Of course you could alternatively buy a GW Models adjustable b-b gauge, set it at a dimension which allows your stock to go through the pointwork, be it 14.3, 14.55 or whatever, then set everything else to that same figure.

The greatest advantage of this is that when you finally see the light and go EM or P4 you can still use the same gauge.

Simples.