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EMGS commissions Peco for RTR EM Gauge bullhead track/turnouts

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If I may, it isn’t just the flange thickness that can often cause problems, crucial as it is, but the combined tyre profile in respect of the root radius. Sometimes this can be quite small, on occasion appearing to be no more than a sharp corner, and at others such a large radius there is little actual tyre tread. The latter is particularly problematic as it gives little real wheel grip on the rail head whilst needing a narrower btb if the piece of rolling stock isn’t to run on it most of the time and appear to wobble along the track.

 

Izzy

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2 hours ago, martin_wynne said:

 

Hi John,

 

I can't comment on how useful that advice is, but it's just plain wrong. For all gauges, not just EM.

 

The dimension that remains constant is the check gauge. For EM that is 17.2mm. For 00-SF and 00-BF and 00-DOGA-Intermediate it is 15.2mm.

 

Then to find the optimum back-to-back for any wheels you subtract the flange thickness from the check gauge.

 

For RTR wheels the flange thickness is typically 0.8mm. so the optimum back-to-back for RTR wheels in EM is 17.2mm - 0.8mm = 16.4mm.

 

For Romford/Markits wheels the flange thickness is typically 0.7mm. so the optimum back-to-back for Romford/Markits wheels in EM is 17.2mm - 0.7mm = 16.5mm.

 

For kit wheels such as Ultrascale/Gibson/EMGS wheels the flange thickness is typically 0.6mm. so the optimum back-to-back for Ultrascale/Gibson/EMGS wheels in EM is 17.2mm - 0.6mm = 16.6mm.

 

Unfortunately the mantra that the back-to-back is a fixed dimension is so ingrained in the hobby that I doubt my posting the above information yet again is going to make any difference. For more info see: http://4-sf.uk (add 2.0mm for EM).

 

cheers,

 

Martin.

 

Martin

 

I have never said or this modeller that the check gauge should be altered at all. He uses the standards laid down by the EMGS

 

I don't think the modeller used Romfords, as altering the Back to back of these is nigh on impossible for the average modeller. I do understand that the most important element is the check gauge. I think in his own way this person was using one type/make of wheel across all stock and sticking to it. He interest was in the performance of the stock. His expectation was that the trackwork was built to a high standard but stock must run through it without any hiccups

 

It could be argued that by mixing wheels of the same scale but built to differing standards could lead to mixed performance, certainly I found that PC coach wheels were more likely to cause issues when I was using RTR turnouts than Romfords. Certainly the standards of RTR wheels do vary considerably 

 

Not arguing with your advice on trackwork, just saying what worked very well for one modeller

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27 minutes ago, hayfield said:

I think in his own way this person was using one type/make of wheel across all stock and sticking to it.

 

Hi John,

 

Obviously if your friend is using only one type of wheel, then he will be using the same back-to-back for all of those wheels.

 

But you seemed to be saying that the same back-to-back should be used for ALL wheels. Which is not the case for best results.

 

I think too much is made about using only one type of wheel. Wheels (especially RTR) have changed a lot since the original standards were written. You know that different makes of wheel will work fine on 00-SF, and EM can use exactly the same mix of wheels -- EM is the same as 00-SF, just 2mm wider.

 

To work on EM and 00-SF wheels need to comply with these limits:

 

Minimum overall width 2.3mm

 

Maximum flange thickness 0.8mm

 

All wheels from modern RTR to Ultrascale 00/EM fall within those limits, and will run just fine on EM and 00-SF. For best results they just need setting to an appropriate back-to-back, as I indicated in my previous post. For EM none of them should have a back-to-back less than 16.3mm, or less than 14.3mm for 00-SF.

 

The only wheels which don't comply are P4 wheels (too narrow) and old Triang/Dublo RTR wheels (flanges too thick). Also some traders use the same narrow P4 width for their so-called "00/EM" wheels, which as a result are in fact useless for 00 or EM.  

 

You mentioned that Romford/Markits wheels are not adjustable for back-to-back. But they don't need adjusting because their fixed back-to-back matches the exact requirement for EM. Indeed, it is those wheels which the EMGS track standards were originally based on. It is the other types of wheel which need a different back-to-back for best results.

 

cheers,

 

Martin.

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1 hour ago, hayfield said:

I don't think the modeller used Romfords, as altering the Back to back of these is nigh on impossible for the average modeller.

 

 

The following is not intended to directly relate to the above issue,  but I discovered recently (via the EMGS Newsletter?) that Markits produce washers (0.1 or 0.2mm thick?) which have the correct flat sided holes in the centre to match Markits/Romford self-quartering axles.  Obviously you couldn't use too many washers on each side (one or two maybe), otherwise you'd risk wobbly wheels...

 

HTH

Brian

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14 minutes ago, polybear said:

The following is not intended to directly relate to the above issue,  but I discovered recently (via the EMGS Newsletter?) that Markits produce washers (0.1 or 0.2mm thick?) which have the correct flat sided holes in the centre to match Markits/Romford self-quartering axles.  Obviously you couldn't use too many washers on each side (one or two maybe), otherwise you'd risk wobbly wheels...

 

Hi Brian,

 

Presumably those are intended to convert the Markits 00 wheels for use on DOGA-Fine? They shouldn't be needed on 00-SF or EM.

 

cheers,

 

Martin.

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Some of us use 16.65 B2B with Gibson type wheels due to the finer flanges and as most if not all the rolling stock on my layout have Gibson then all the track is tightened up to suit. I also have Ultrascale wheels on some locos but these are set to 16.6 B2B and everything works very well. I have tried this opening out the RTR wheels to 16.5 B2B on a few wagons but find that it's not the best idea for me so I'll stick with what I know works for me.

A short video of some wagon testing, all Gibson wheels :-

 

 

Dave.

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41 minutes ago, polybear said:

 

The following is not intended to directly relate to the above issue,  but I discovered recently (via the EMGS Newsletter?) that Markits produce washers (0.1 or 0.2mm thick?) which have the correct flat sided holes in the centre to match Markits/Romford self-quartering axles.  Obviously you couldn't use too many washers on each side (one or two maybe), otherwise you'd risk wobbly wheels...

 

HTH

Brian

Its 247 Developments that make the washers nor Markits

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25 minutes ago, martin_wynne said:

 

Hi Brian,

 

Presumably those are intended to convert the Markits 00 wheels for use on DOGA-Fine? They shouldn't be needed on 00-SF or EM.

 

cheers,

 

Martin.

there Washers are made by 247 Development & yes there are for DOGGA-Fine

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11 minutes ago, davefrk said:

I have tried this opening out the RTR wheels to 16.5 B2B on a few wagons but find that it's not the best idea for me so I'll stick with what I know works for me.

 

Hi Dave,

 

For use on standard EM, RTR wheels should be set to 16.4mm back-to-back. If you set them to 16.5mm they will likely contact the nose of the crossings and run rough through pointwork as a result.

 

cheers,

 

Martin.

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17 minutes ago, mozzer models said:

Washers are made by 247 Development & yes there are for DOGA-Fine

 

Should a responsible member of the trade be encouraging use of DOGA-Fine? It has been the cause of so much confusion and disappointment that it's time it was scrapped and buried for good.

 

If C&L, DCC Concepts, et al, had the interests of their 00 customers at heart, they would be throwing their entire stock of DOGA-Fine gauges in the bin.

 

Martin.

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Hi Martyn, yes I agree but they were tight on a couple of of the tightened up checkrails at 16.4 and I tried to find the happy medium but there wasn't one so in the bin with them.

 

Dave.

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1 minute ago, martin_wynne said:

 

Should a responsible member of the trade be encouraging use of DOGA-Fine? It has been the cause of so much confusion and disappointment that it's time it was scrapped and buried for good.

 

If C&L, DCC Concepts, et al, had the interests of their 00 customers at heart, they would be throwing their entire stock of DOGA-Fine gauges in the bin.

 

Martin.

But if someone is already working to this gauge then there needs still need to be supplied we were ask to make some & as they sell we will still keep them in stock

 

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7 minutes ago, davefrk said:

Hi Martyn, yes I agree but they were tight on a couple of of the tightened up checkrails at 16.4 and I tried to find the happy medium but there wasn't one so in the bin with them.

 

Hi Dave,

 

If you have "tightened up the check rails" then you are no longer using standard EM and none of my previous remarks apply.

 

Your new standard might be fine, but PLEASE, PLEASE, PLEASE give it a new name and don't tell folks you are using EM.

 

Have you seen the EM-SF standard? A few folks are using it and it's available as a pre-set in Templot. 18.0mm gauge with 0.8mm flangeways, using the Exactoscale 0.8mm check rail chairs. RTR wheels won't run on it, but all others do, using exactly the same back-to-backs as standard EM. So new pointwork to EM-SF can be mixed with standard EM on the same layout.

 

Martin.

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Here we are discussing one gauge  (18,2 mm if anybody missed it) and still it descends; or maybe that is "ascends" into a "mini" gauge war.

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16 minutes ago, Enterprisingwestern said:

Therein lies my inconsistency!

 

I think you can buy special underpants for that.

 

P

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For all the numbers being floated around, has anyone actually laid any EMGS track as part of a layout and had any problems getting trains to go around it? 

 

 

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1 hour ago, martin_wynne said:

 

Hi Dave,

 

If you have "tightened up the check rails" then you are no longer using standard EM and none of my previous remarks apply.

 

Your new standard might be fine, but PLEASE, PLEASE, PLEASE give it a new name and don't tell folks you are using EM.

 

Have you seen the EM-SF standard? A few folks are using it and it's available as a pre-set in Templot. 18.0mm gauge with 0.8mm flangeways, using the Exactoscale 0.8mm check rail chairs. RTR wheels won't run on it, but all others do, using exactly the same back-to-backs as standard EM. So new pointwork to EM-SF can be mixed with standard EM on the same layout.

 

Martin.

Hi Martyn, I know where you are coming from but it's still EM 18.2mm gauge but I do say that I've slightly tightened up some specs. I'd spoken to a number of EMGS board members about it when they were looking into the fact that a few members have done the same with modern finer wheels and the consensus was if it works for you then okay but the EM specs still stand. I don't believe it needs a new name as it's just tweeking the specs to suit my or some others way of doing things.

 

Cheers,

Dave.

Edited by davefrk
Message disappeared on posting.
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5 minutes ago, sharris said:

For all the numbers being floated around, has anyone actually laid any EMGS track as part of a layout and had any problems getting trains to go around it? 

 

 

 

You'll never catch anyone doing that, it's called modelling!

 

Mike.

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1 minute ago, sharris said:

For all the numbers being floated around, has anyone actually laid any EMGS track as part of a layout and had any problems getting trains to go around it? 

 

 

 

What a radical idea. Try some and see if it works. Where exactly is the fun in that compared to all the number crunching?

 

I haven't seen any in serious use yet.

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5 minutes ago, davefrk said:

Hi Martyn, yes I know where you are coming from but it's still EM 18.2mm gauge but I do say I have tightened up some specs. I'd spoken with a number of board members about it when they were looking into the fact that a number of members were working to a very slightly tighter spec with the modern finer wheels and the concensus was if that works for you then fine, no mention of different names, but I'll take your point.

 

Hi Dave,

 

I don't know where board members come into it. It's the technical people you need to talk to, perhaps the guy on the CAD system at Peco?

 

By all means tighten up the EM dimensions, but do it properly. That means leaving the check rails where they are at 17.2mm check gauge, and tightening in the stock rails, i.e. reducing the track gauge, not "still 18.2mm". That way, with the critical check gauge unchanged, all the back-to-backs remain the same. so the wheels are unchanged and you can mix the new standard with the old on the same layout.

 

Notice that the EM-SF standard which I mentioned does exactly that, with the check gauge still at 17.2mm and no need to change wheels. The check gauge is far and away the most important dimension, far more than minor tweaks to the track gauge, which is the least important dimension.

 

The reason it is so important to give each standard its own name is to avoid confusing beginners. If someone is starting in standard EM and asks what back-to-back dimensions to use, there is no point in asking you what back-to-backs you use because you are not using standard EM. He needs to find someone who IS using standard EM, and ask them. On the other hand, if he sees your trains running well, you might persuade him to adopt your EM-DAVE standards instead of standard EM.

 

cheers,

 

Martin.

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On 24/10/2019 at 12:02, t-b-g said:

 

Spot on Martin. I wonder if the reason why people get poor running is because of a lack of understanding of the relationship between wheels, flanges, gauge, check rails etc.

 

It is such a shame that after all these years, manufacturers are still making wheels with different thickness flanges. If they made them all to a fixed standard, you could rely on a back to back gauge as a fixed dimension. Until that time (which will probably never happen) people need to be aware of the differences outlined by you. Mike Sharman used to recommend 16.7mm back to back for his wheels, which had thinner flanges than most. If you set opened up ready to run wheels at 16.7mm back to back, they don't fit between the rails!

Hi,

I would just like to add a couple of points further to the excellent advice of both Tony and Martin. 

 

Firstly when I discussed back to backs with Mike Sharman soon after he started making his wheelsets he would not specify a back to back measurement for his wheels.  Instead he explained his own process for determining the correct back to back for any wheel on any gauge with the following illustration which I have reproduced for EM (18.2) gauge.

 

25630570_BacktoBackVsGauge.JPG.75b510bbad0322f35e7bc5aed8c7543b.JPG

 

As can be seen from the illustration the critical elements are that the back to back must be greater than the check span (i.e. greater than 16.2mm in EM) otherwise the wheels will bind in the check rails.  Additionally the back to back must be sufficiently narrow as to guide the flange smoothly into the V's flangeway.  Too wide and the flange will hit the nose of the 'V'.  There will be more or less 'wiggle room' depending upon the thickness of the flanges but it is best to keep the back to back as wide as possible to reduce the tendency of the vehicle to 'crab' which increases the risk of buffer locking. 

 

From my experience of a number of RTR locomotives that I have converted to EM for friends I can confirm that there is considerable variation in the flange thicknesses for different models and not all are immediately suitable for re-gauging.  I have regularly found RTR flanges of 1mm thickness or more which would if unmodified bind and jump in the flangeways. Fortunately I have a lathe and have been able to thin down such flanges by skimming the backs of the wheels, so far with complete success.  I am currently converting a Heljan 47xx for myself and have performed the same modification on the wheels plus a new set of wider axles to suit.

 

Martin's comment that the critical measurement is the check span and check gauge (17.2mm in EM)  rather than the track gauge was a light bulb moment for me.  Deviate from this and you are no longer modelling in EM as the Society would understand it.

 

Regards,

Frank  

 

Back to Back Vs Gauge.PDF Back to Back Vs Gauge.PDF

Edited by Chuffer Davies
To correct terminology and an error in one of the measurements so as to align with Martin’s entry.

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17 hours ago, davefrk said:

Some of us use 16.65 B2B with Gibson type wheels due to the finer flanges and as most if not all the rolling stock on my layout have Gibson then all the track is tightened up to suit. I also have Ultrascale wheels on some locos but these are set to 16.6 B2B and everything works very well. I have tried this opening out the RTR wheels to 16.5 B2B on a few wagons but find that it's not the best idea for me so I'll stick with what I know works for me.

A short video of some wagon testing, all Gibson wheels :-

 

 

Dave.

 

 

Dave

 

I must say that is a very impressive demonstration, certainly down to the quality of the modelmaking involved. For us mere mortals the lesson must be to ensure that its the quality of the build and adherence to the standards is a must. certainly a vote for using wheelsets which are of the same/similar construction.

 

As for tampering with the gauge standards I bow to Martins superior knowledge on the subject 

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17 hours ago, martin_wynne said:

 

Hi Dave,

 

If you have "tightened up the check rails" then you are no longer using standard EM and none of my previous remarks apply.

 

Your new standard might be fine, but PLEASE, PLEASE, PLEASE give it a new name and don't tell folks you are using EM.

 

Have you seen the EM-SF standard? A few folks are using it and it's available as a pre-set in Templot. 18.0mm gauge with 0.8mm flangeways, using the Exactoscale 0.8mm check rail chairs. RTR wheels won't run on it, but all others do, using exactly the same back-to-backs as standard EM. So new pointwork to EM-SF can be mixed with standard EM on the same layout.

 

Martin.

 

Martin

 

I broadly agree with you, but is someone wants to use DODA fine standards and go into it with their eyes wide open, then that's fine 

 

As for gauges you are spot on, yes in the past C&L sold gauges where the 00 ones were to DOGA fine, BUT that was in the past. This year Phil has had his gauges redesigned, firstly to ensure (as you would expect) they work perfectly with chaired track (allows the rail head to rotate in the gauge), and at the same time changing the 00 gauges to 00-BF

 

If you look at most sites of either retailers and societies, I do not think any confirm that the gauges are plastic chair compatible. I personally treat all gauges as non plastic chair compatible until they are proved to the contrary. Those of us who build chaired track know, the rail head must rotate in the slot of the track gauge to allow for the cant of the rail, if the width of the slot is too narrow and or too deep the rail will be held too upright, once the gauge is removed gauge narrowing could occur

 

Certainly the modern style Exactoscale P4 gauges were compliant, easy to use and had a set of gauge widening gauges, sadly these are no longer available,  

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