31.5 vs. 32mm gauge

[Guest Isambarduk]

..., if I were to go to a show - and buy a Heljan or Dapol loco - or some Peco or Parkside Dundas wagon kits, or Peco or Slaters' wheelsets - without specifying which of these gauges I wanted, I wonder which gauge I'd be more likely to get (and how easily I'd notice the difference).

 

Just to be absolutely clear here: you would get what anybody else would get. 

 

The rolling stock is not built specifically for 32.0mm, 31.5mm or 31.25mm track gauge, the wheel standards are the same no matter whether you buy or build your track for 0-F (Fine, 32.0mm gauge), 0-MF (Medium Fine, 31.5mm gauge) or for 0-SF (Super Fine ,31.25mm gauge) track standards. 

 

This is all laid out in the G0G Standards that are to be republished imminently.

 

David

Edited July 30, 2017 by Isambarduk

[3 link]

And then we are not just talking about " gauges " , you also have the different width wheel treads and depth of flange to consider, as not all manufacturers keep to a particular standard.

 

I could go on, but life's to short.......

 

Martyn.

[jim.snowdon]

A search on Roxey's web site only brought up OO roller gauges.

 

Are Deb's gauges not available now?

 

I was actually planning a cheapskate approach and going to try making them myself. My brother made some 28.08mm 3 point gauges for me. He may be an experienced engineer, and I'm not, but O-MF is less precise that P4 broad gauge! I also have another idea, but I'm not telling unless it works .

Patently Dave (Roxey) still hasn't updated his website. The gauges he does are those that I designed when we built our current club layout (and are therefore proven) and I know that has ordered more as I had to remind him of the etch tooling reference. Suggest you give him a call.

 

Jim

[BG John]

Patently Dave (Roxey) still hasn't updated his website. The gauges he does are those that I designed when we built our current club layout (and are therefore proven) and I know that has ordered more as I had to remind him of the etch tooling reference. Suggest you give him a call.

 

Jim

Very speedy reply to my e-mail to Dave:

 

I produce two track gauges for 31.5mm.

7A3150 is a pair of etched, fold-up gauges for 31.5mm at £4.50

7A3175 is a pair of etched, fold-up gauges for 31.75mm for gauge widening on curves at £4.50

UK P&P per order is £3.00 or they will be on the stand at Telford.

[Debs.]

.....Are Deb's gauges not available now

Indeed they are......Please P.M for further details.

Deb.

[BG John]

Indeed they are......Please P.M for further details.

Deb.

PM sent.

[Giles]

Plus one for Deb's roller gauges...... I wouldn't be without mine!

[Chris116]

As someone who has worked in OOO, TT3 and OO, I have yet to work in a gauge which is correct! However I cannot understand why modellers who are aiming for more accurate models choose a gauge that is further from correct. I think 7mm scale track should be 32.9583mm and also cannot understand why it is possible to run with check rails closer to the running rails when using a smaller gauge but not when using the correct scale gauge.

[Nearholmer]

Chris

 

Isn't the issue here about super-smooth operation using readily available wheel-sets, rather than absolute dimensional fidelity to prototype, which brings with it all sorts of impracticalities for most railway modellers?

 

My understanding from this thread is that there is a minor incompatibility between the wheel and track standards in G0G fine, so that to get super-smooth running one either has to move to slightly different track or wheel dimensions, and that it is a lot easier to build track to a slightly different track gauge than it is to make wheels, with very slightly wider treads than G0G 'fine', for oneself.

 

Kevin

Edited July 31, 2017 by Nearholmer

[jim.snowdon]

Chris

 

Isn't the issue here about super-smooth operation using readily available wheel-sets, rather than absolute dimensional fidelity to prototype, which brings with it all sorts of impracticalities for most railway modellers?

 

My understanding from this thread is that there is a minor incompatibility between the wheel and track standards in G0G fine, so that to get super-smooth running one either has to move to slightly different track or wheel dimensions, and that it is a lot easier to build track to a slightly different track gauge than it is to make wheels, with very slightly wider treads than G0G 'fine', for oneself.

 

Kevin

In simple terms, correct, and since many of us build track but few make wheels, adjusting the track gauge to fit the wheelsets was the obvious thing to do to correct the error, which goes back many decades. Plus, it has the advantage that interchangeability of rollingstock between different members layouts and vice versa, as in the club environment, is preserved.

 

The alternative is what resulted in Scaleseven, where they just started again and, by scaling the prototype dimensions, avoided any of the thinking. It has its benefits in loco building, but beyond that, it is difficult to distinguish a Scale seven layout from a good 31.5mm gauge one at normal viewing distances and Sceleseven modellers have to exist in a parallel universe as far as stock interchangeability is concerned.

 

Jim

[t-b-g]

As someone who has worked in OOO, TT3 and OO, I have yet to work in a gauge which is correct! However I cannot understand why modellers who are aiming for more accurate models choose a gauge that is further from correct. I think 7mm scale track should be 32.9583mm and also cannot understand why it is possible to run with check rails closer to the running rails when using a smaller gauge but not when using the correct scale gauge.

I am not sure that anybody advocating 31.5mm has suggested that it is more accurate and the sort of track you mention is very much in use by the Scale 7 modellers.

 

The idea is to obtain smoother running and a slight improvement in the way the points look by getting a smaller gap between check and running rails, despite the slight reduction in gauge.

[robertc]

Chris

 

Isn't the issue here about super-smooth operation using readily available wheel-sets, rather than absolute dimensional fidelity to prototype, which brings with it all sorts of impracticalities for most railway modellers?

 

My understanding from this thread is that there is a minor incompatibility between the wheel and track standards in G0G fine, so that to get super-smooth running one either has to move to slightly different track or wheel dimensions, and that it is a lot easier to build track to a slightly different track gauge than it is to make wheels, with very slightly wider treads than G0G 'fine', for oneself.

 

Kevin

 

In a way you are correct Kevin!

A properly designed set of standards does not allow the wheel to drop into the frog. It is supported by the rail head all the way. What you call super-smooth running is actually the norm. By reducing the flangeway to suit the wheels treads on offer and a matching reduction in the track gauge to keep the same check gauges, the O-mf track standard fits the FS wheel.

 

The other option of using wheels with a wider tread works out well for those who have use of  the regular NMRA RP25-172 wheels as supplied for the US 2-rail market.

At about 4.4 mm in width they run nicely through a FS point such as supplied by Peco. No wheels dropping into frogs.

 

 

regards

 Bob

[martin_wynne]

The other option of using wheels with a wider tread works out well for those who have use of  the regular NMRA RP25-172 wheels as supplied for the US 2-rail market.

At about 4.4 mm in width they run nicely through a FS point such as supplied by Peco. No wheels dropping into frogs.

 

This of course explains why we need 0-MF (31.5mm) in the first place. Firms such as Slater's introduced narrower wheels, because they look nicer, claiming that they were compatible with existing 0 Gauge Fine standard track. When in fact they weren't. Other firms then followed suit. If the industry standard for 0 Gauge wheels was still 4.0mm wide or wider, no-one would have needed to come up with 0-MF.

 

The same applies in 00, where the trade routinely supplies narrow EM-width wheels for 00. Hence the need for the similarly reduced gauge 00-SF (4-SF) to keep such wheels fully supported through crossings.

 

Martin.

[Simond]

Chris,

 

The reason that an "even narrower" gauge works is because there is a desire to use existing wheelsets. The wheelset dimensions are used to define the track.

 

The current GOG-F 32mm track, coupled with the standard back to back defines flangeways that are wider than they need to be, and, crucially, permit wheel-drop at the crossing, because the width of the tyre is less than the sum of the flangeway and railhead widths. In other words, despite the long history, the current 32mm standards are fundamentally flawed. (Edit: "or, perhaps more accurately, the current standards and currently available commercial wheelsets are not compatible")

 

There are three approaches to fixing this: move to 33mm, and correct flangeways, make the tyre wider, or change the track gauge by 0.5mm, and crucially make the flangeways narrower by half of this. Of course, there is a fourth option, simply live with it.

 

Going to 33mm gauge prohibits the existing wheelsets, so anyone wanting to use it has to rewheel their stock. You certainly would have your check rails at scale positions in S7.

 

Wider tyres are less visually attractive, less accurate, and compromise stock manufacture and minimum curving radius.

 

Reducing the gauge by 0.5mm reduces the flangeways, which subsequently look more realistic, and eliminates wheel drop. You cannot see 1mm difference in gauge, still less 0.5mm, but you can see the difference in the flangeways because you can compare them to the railhead width. And you can still run unmodified stock.

 

And the improved running, coupled with being able to run all my stock collection, plus any visitors' stock, unmodified, is the reason I (and many others) have adopted 31.5mm.

 

If I were starting from zero, I might have chosen S7, but I'm not. My choice, driven by the collection I have, was between 31.5 & 32, and personally, and given I'm building my own track, I can see no sensible reason for choosing 32.

 

Best

Simon

Edited August 1, 2017 by Simond

[Nearholmer]

Bob

 

"What you call super-smooth running is actually the norm"

 

Strangely, for all the national obsession with track and wheel standards, that seems not to be true in Britain. We have a slightly bumpy G0G standard, and 00 practices still don't all match the smoothness of RP25.

 

Anyway, back to my bumpy old coarse scale ......... oh, wait a moment ....... it's actually pretty smooth, and I can happily propel long trains ....... because the wheel treads are wide enough to ride nicely through the crossings!

 

Kevin

[Simond]

Just like all the boy racers, wide wheels...  

[Metropolitan H]

................. and I can happily propel long trains ....... because the wheel treads are wide enough to ride nicely through the crossings!

 

Kevin

 

That last bit is not just due to the width of the wheel treads. The use of rigid single link couplers of the B-L / Hornby / ACE / etal. type has a very significant - probably greater - influence on the ability to propel vehicles through curves / crossings / reverse curves.

 

Whatever, I have become very happy with the ability of "O" gauge "Coarse / Standard" scale trains to get round the 27inch (equivalent of 15inch in OO) radius curves and turnouts - I can enjoy running the trains round in a relatively small space, while sitting and watching / doing something else.

 

Regards

Chris H

[Northroader]

Bob

"What you call super-smooth running is actually the norm"

Strangely, for all the national obsession with track and wheel standards, that seems not to be true in Britain. We have a slightly bumpy G0G standard, and 00 practices still don't all match the smoothness of RP25.

Anyway, back to my bumpy old coarse scale ......... oh, wait a moment ....... it's actually pretty smooth, and I can happily propel long trains ....... because the wheel treads are wide enough to ride nicely through the crossings!

Kevin

I feel duty bound to testify to the smoothness of running on Kevin's line, as he was kind enough to turn me loose on it. Better than mine, which is finescale 0, 32mm sort of. This could also be due to him being a better craftsman than me. I laid mine using gauges, but I darent certify just what its ended up as, particularly around points. Could I state I'm capable or working to the nearest 1/2 mm? Not really, some folks on here probably could, but they are rarities. This is what causes a smile when a superfine, just like the prototype, modeller works out what standard gauge scaled down is on his calculator, and calmly states he is working to a hundredth of a millimetre. Maybe In the tool shop of the Harwell atomic weapons research they can do it, but not on joe Bloggs layout. Edited August 1, 2017 by Northroader

[sir douglas]

i dont get this arguement about the running quality necessarily being better for certain in 31.5mm than it is in 32mm the the changes that make the difference are the other measurements like check rail gap, you can have a fine check rail gap on 32mm and have just as good running as with 31.5mm and on the other side if you use the standard gap in 31.5mm your going to get sloppy running, its not the gauge that is the issue, its the all the other measurements, 32mm is good enough as long as you use the right flange gaps

[Deano747]

Hello All

 

This is a very interesting thread, as I recently bought quite a few point kits from C&L (before they moved) and of course the crossing V's are made to 32/1.75.

I've ordered some 31.5/1.5 gauges from Debs and will be looking to adjust the V's accordingly as and when I get round to building them.

It looks very much like 31.5 is highly favoured. Of course this is still a very personal choice and I respect all the arguments for and against, but looking at Martyns (3 Link) excellent track work I appreciate the difference. 

 

Anybody want some cheap 32/1.75 gauges!! 

 

Regards, Deano.

[martin_wynne]

you can have a fine check rail gap on 32mm and have just as good running as with 31.5mm

 

Yes you can, but then you must increase the wheels back-to-back to suit. The intention with 0-MF (31.5mm) is to do absolutely nothing to the wheels, so that your models will still run on other 0 gauge layouts, and other models will run on yours. It also means you can use existing pointwork in hidden areas, such as Peco pointwork in a fiddle yard. You can't do that if you have messed with your back-to-backs.

 

When folks say "31.5mm" they are meaning shorthand for the 0-MF standard, i.e. 31.5mm track gauge AND 1.5mm crossing flangeway -- the two go together. It would be helpful, if the title of this topic referred to 0-F and 0-MF rather than simply the track gauge dimension.

 

regards,

 

Martin.

[Nearholmer]

Chris - you're right, of course; I was mildly poking fun.

 

Northroader - kind words, but thank Ron Fraser, who made the points, not me; all I did was lay the track.

 

Kevin

[Tricky]

If, as I've heard stated many times, and as is stated in the item reproduced by Simon, one gets smother running through crossings with 31.5mm, the question that occurs to me is: why? Or, perhaps: how?

 

It ought to be possible to identify the source of the "not smoothness" inherent in the combination of GOG fine wheel and track standards, and illustrate it diagrammatically ....... which I've never seen done.

 

Kevin

 

(Those of a finescale disposition are advised not to look at my thread, because it could easily upset them, although post 71 is very relevant to this discussion)

Correct me if I'm wrong, but smooth running with 31.5mm is achieved because wheels don't drop in the crossing. With the narrower check gauge wheels are fully supported. I think.

[Nearholmer]

Indeed.

[ROSSPOP]

Correct me if I'm wrong, but smooth running with 31.5mm is achieved because wheels don't drop in the crossing. With the narrower check gauge wheels are fully supported. I think.

 

....Or..............    find wagon and van wheels that are a `gnat`s whisker` wider and don`t compensate them.  Peco rather than Slaters.

 

Avoid Peco pointwork.

 

Slaters loco drivers are fine but do compensate.

 

All Lionheart products are fine.  Tower RTR are also fine..........

 

Get to know The Muffin Man...........

 

https://www.youtube.com/watch?v=T8UVguWGtuQ

 

C&L handmade  32mm and that pesky single slip......................

Edited August 4, 2017 by ROSSPOP