0 gauge fine-scale on tight radius curves

[goldfish]

22 hours ago, whizzo said:

if  one  lenz  r1 was placed in the middle of a half circle of  peco r2s  would this work ???

The short answer is no. Lenz track uses Code 143 Flat Bottom Rail, while Peco Setrack uses Code 124 Bullhead Rail. It is not impossible to join the two together, but it would need a little work. Peco do produce a Bullhead to Flat Bottom Transition Track, but this is a 67mm straigth.

[whizzo]

Thank you all  for the answers   i will now make a template  36" radius  and place a piece of peco track   in the middle  of the turn round area - then work in ether side peco set track  rad 2 - hope this makes sense  - will let you know if this works out  //Dave 

[Hal Nail]

Just out of interest, what is the advantage of using set curves rather than just getting flexi? I had assumed the issue was around whether you can get points in a tight radius rather than curves.

[goldfish]

17 minutes ago, Hal Nail said:

I had assumed the issue was around whether you can get points in a tight radius rather than curves.

Getting tight radius points is not a problem, getting things to go through them is another matter...

[F-UnitMad]

15 minutes ago, goldfish said:

Getting tight radius points is not a problem, getting things to go through them is another matter...

What make of track is that?

[goldfish]

4 minutes ago, F-UnitMad said:

What make of track is that?

The track is by ETS, Code 175 and 627mm radius.

[Streamliner]

2 hours ago, Hal Nail said:

Just out of interest, what is the advantage of using set curves rather than just getting flexi? I had assumed the issue was around whether you can get points in a tight radius rather than curves.

With flexible track your curves radius may not be uniform and also the track gauge can vary. Set track being more uniform also has I believe a bit more give / widened, so I think is easier to negotiate. Transition curves is likely to be the major point of stress on couplings or for buffer problems, since the straight to transition curve is the biggest change in direct and largest throw of coach ends.

 

With many purchased rtr finescale capable of negotiating set track and the actual introduction of set track making this obvious, more people are opening up to this suggestion especially if they have limited space and 6' curves are not viable.

Rtr generally have been made with more clearances when compared with kits, where the kit manufacturer has been more concerned with a representative/accurate model. Many finescale modellers wanting to build an accurate representation however a few also want to operate their models in the space available to them.

It's a case of looking comparing those rtr and if building a kit, checking and adapting to your goal radius.

I have a kit made Duchess (Coronation - purchased 2nd hand) which I have been inspecting & testing on set track, and using this and also other rtr to help me set up my Princess 4-6-2 chassis to also run round set track curves.

The bogie movement and clearance, trailing axle throw, pivot point and clearance, coupling wheel movement, side-play, cylinder clearances, chassis spacing, motor thickness, weighting and any chassis or component interference (eg brake gear as well as a few others), all may need considering...

If you want to be able to negotiate your curves successfully.

As Harold (in the Nov 20 GOG gazette) in his layout has shown.... it (tight radiuses) can be achieved with compromises. 

We each have different limits as to what we want to compromise on...

Edited November 8, 2020 by Streamliner
Correction & ref article added

[Donw]

The other problem with using flexitrack at tight radii is because of the way the sleeprs are tie with little webs alternate sides at tight radii the sleeper are not always perpendicular to the rail and can therefore reduce the radius very slightly just when you can least afford that. If you carefully cut all the webs and align the sleepers it should avoid the problem.

 

Don

[hartleymartin]

You can get the big American O gauge around a 36" radius curve because you don't have buffers, and it is all on bogies.

 

You can probably get 0-4-0s and 4-wheel stock around the same curve if you transition the curve at each end and have very loose 3-link couplings.

[Ian Kirk]

As far as I am aware all of the British outline RTR (except for the expensive brass ones) produced recently have been designed to go around the set track curves.  This has opened up the possibility of a continuous run layout in spaces under 12 ft wide. Problem comes and the same can be said about 00 layouts involving R1 and R2 curves if you want to try and run big locos and full length coaches in that they look decidedly unrealistic on the curves. The late CJF designed one 00 trackplan to deal with this, basically an oval with very tight curves in tunnels either end, fiddle yard at back and station (viewed area) at the front. THe spectators never saw the undignified progress around the curves.  So gentle curves on most of the layout and hide the tighter bits seems to work. Alternatively model an industrial scene with small locos and these tight radii are prototypical.  In O gauge I am working on a harbour model  using quite a lot of setrack curves. I have found by experiment though that small locos can go down tighter yet. In real life short wheelbase 4 wheel wagons and small industrial 0-4-0 tanks were designed to go round one chain radius (66ft) which works out about 18 inches. I have some bits of 2ft radius and the 0-4-0 "pugs" go round that fine. If the bigger 0-6-0T locos won't, no problem, they would not have been allowed there in real life anyhow.

 

best wishes,

 

Ian

[Andy Reichert]

I can run HO  4 wheel bogie vehicles reliably on 8 in radius, even with proto-scale wheels, provided the bogies can turn sufficiently without hitting under body obstructions. For 6 axle and greater vehicles and bogies, minimum radius is set both by the amount of sideways movement of the "Mid" axles of a multi-axle vehicle and the track gauge.

 

Note that 0 SF and 00 SF folks have a dramatically greater min. radius running the same RTR  6 axle and greater vehicles due to gauge narrowing.

 

 

 

You can partially avoid buffer and/or coupler lock on tight same direction curves by using  transition curves in and out of the curve. That can be handy for loop backs.  The diagram shows transitions in and out of  a 25" radius loop back.  I could have made the mid radius even tighter by continuing the transitions right in to the centre of the loop. But I have scale QuintArts that cannot be bent more than 25" radius.

 

Andy

 

[JinglingGeordie]

It might be a thought for manufacturers to put a minimum radius in the specifications for kits they are building, or in the reviews on here, in magazines or Guild publications. I appreciate not all manufacturers may wish to create a series of test radii of course. 

 

Perhaps the Guild could see if there is a market for tighter radii, or an other group. 

 

 

[goldfish]

Not a very good example, or a great image, but a practical example none the less of fine scale 0 gauge on tight radius curves.

Walsworth Models Sentinel and Dapol 7-plank wagons on ETS 627mm radius track. Bit of a cheat because they are all fitted with single link couplings. I do not have the facilities to make videos, so you will have to take my word for it that they go through the reverse curves with no problem, backwards and forwards.

[New Haven Neil]

I use setrack exclusively, as 1 I used to sell it, and 2 it saves kinks on curves, which you can't afford in such tight radii.

 

The Minerva Victory needed larger buffers to be able to propel wagons through a reverse curve in a crossover, oddly the Panniers don't.  Must be the overhangs.

 

There is nothing bigger than a 57 on the layout, but given the compromises accepted it looks OK.

 

 

 

 

[Donw]

1 hour ago, New Haven Neil said:

I use setrack exclusively, as 1 I used to sell it, and 2 it saves kinks on curves, which you can't afford in such tight radii.

 

The Minerva Victory needed larger buffers to be able to propel wagons through a reverse curve in a crossover, oddly the Panniers don't.  Must be the overhangs.

 

There is nothing bigger than a 57 on the layout, but given the compromises accepted it looks OK.

 

 

 

 

 

Looks good Neil.  Did you know the Forest of Dean not your area I thought. I didn't move there until after the lines had been closed but have walked nearly all of the old lines with the dogs. We have since moved away. Do you still have the garden line as well.

 

Don

[PatB]

On 10/11/2020 at 22:32, JinglingGeordie said:

It might be a thought for manufacturers to put a minimum radius in the specifications for kits they are building, or in the reviews on here, in magazines or Guild publications. I appreciate not all manufacturers may wish to create a series of test radii of course. 

 

Perhaps the Guild could see if there is a market for tighter radii, or an other group. 

 

 

The trouble with specifying minimum radii for kits is that there is often sufficient variation between examples by different builders that any such figure quoted by the manufacturer becomes meaningless. This is particularly the case with many older kits where the builder is largely left to their own devices as far as running gear details are concerned. Certainly, were I a manufacturer, I'd be reluctant to specify a firm minimum, based on a kit that I'd built. I'd want to avoid having to field calls from builders disappointed after taking out all the axle sideplay, building the chassis twisted and then trying to run the thing on flextrack the shape of a 50p coin. 

[MarcD]

On my micro layout I've got peco set track. But I don't have anything bigger than a terrier and a 9ft WB wagons. I don't have any problems with 3link couplings but I hav had to produce a modified Dingham coupling that can cope with the reverse curves.

On the S7 layout I'm working on I've gone for a A4/5ft minimum for it and I'm only using GER tram and small tanks.

 

Marc

[Ray H]

1 hour ago, Furness Wagon said:

. . . . . but I have had to produce a modified Dingham coupling that can cope with the reverse curves. . . . . 

 

Marc

 

What modifications did you make Marc?

[MarcD]

the loops are 1 1/2x bigger on width. I etched them up in 18thou NS. the standard ones are ok on 4ft6 or greater but they get temperamental below that so I made the wider. no problems now.

 

Marc 

[Izzy]

I think a lot here, while being specific to 7mm, are also layout design problems and solutions common to most scales. For small layouts of minimal size two ways to offset buffer locking issues are either to put it all on a curve, so there are no reverse curves through crossovers, or just use mostly wyes. Either can be a challenge depending on what is hoped for looks wise but can be the easiest/simplest solution, no stock needing any modification normally.

 

Using wyes is useful in that much larger radius can be used with the pointwork also being much shorter in length. I’ve just built some A3’s of 36” rad which are about 17” from toe-to-toe as a crossover. This was in O-MF. 
 

Izzy

[New Haven Neil]

22 hours ago, Donw said:

 

Looks good Neil.  Did you know the Forest of Dean not your area I thought. I didn't move there until after the lines had been closed but have walked nearly all of the old lines with the dogs. We have since moved away. Do you still have the garden line as well.

 

Don

 

Hi Don, thank you.  Hope you're well.

 

Yes, somewhat of a change in direction and scale, I needed a change!  Not an area I know well (although favourite nephew lives not too far away) but the Ben Ashworth book brought me to it - I have several others now also.  Such an interesting area.

 

The garden line lives on, a little ignored this year with working so hard trying to save the business, but that's all behind me now, next year it will get run a lot more.  

[goldfish]

The “Organization of Model Railroaders and Railway Friends Europe", otherwise known as MOROP, provide recommendations for minimum radii based on the dimensions of the prototype, scenario, and type of coupling. The recommendations are intended to be universal and are expressed in terms of multiples of the track gauge ( G ). MOROP publish their standards in French and German, so here is my interpretation of them, with help from Google Translate.

 

The recommended minimum radii are contained in NEM 111, and are in two parts. Section 3.1 gives minimum radii where the coupling prevent contact between buffers, and section 3.2 gives minimum radii where the coupling allow contact between buffers. The recommendations are given in the terms of multiples of the track gauge. I have added the corresponding values for 32mm gauge.

 

The Groups are detailed in NEM 103 where Bogie cars are classified into three groups:

Group A - Body length up to 20.0 m. Distance between bogie pivots up to 14.0 m.

Group B - Body length up to 24.2 m. Distance between bogie pivots up to 17.2 m.

Group C - Body length up to 27.2 m. Distance between bogie pivots up to 19.5 m.

 

For couplings where buffers cannot touch:

 

For couplings where buffers can make contact Group A is subdivided into three:

 

https://www.morop.org/downloads/nem/de/nem103_d.pdf
https://www.morop.org/downloads/nem/de/nem111_d.pdf
https://www.morop.org/downloads/nem/fr/nem103_f.pdf
https://www.morop.org/downloads/nem/fr/nem111_f.pdf

 

Edited November 26, 2020 by goldfish

[F-UnitMad]

2 hours ago, goldfish said:

The “Organization of Model Railroaders and Railway Friends Europe", otherwise known as MOROP, provide recommendations for minimum radii based on the dimensions of the prototype, scenario, and type of coupling. The recommendations are intended to be universal and are expressed in terms of multiples of the track gauge. MOROP publish their standards in French and German, so here is my interpretation of them, with help from Google Translate.

 

The recommended minimum radii are contained in NEM 111, and are in two parts. Section 3.1 gives minimum radii where the coupling prevent contact between buffers, and section 3.2 gives minimum radii where the coupling allow contact between buffers. The recommendations are given in the terms of multiples of the track gauge. I have added the corresponding values for 32mm gauge.

 

The Groups are detailed in NEM 103 where Bogie cars are classified into three groups:

Group A - Body length up to 20.0 m. Distance between bogie pivots up to 14.0 m.

Group B - Body length up to 24.2 m. Distance between bogie pivots up to 17.2 m.

Group C - Body length up to 27.2 m. Distance between bogie pivots up to 19.5 m.

 

For couplings where buffers cannot touch:

 

For couplings where buffers can make contact Group A is subdivided into three:

 

https://www.morop.org/downloads/nem/de/nem103_d.pdf
https://www.morop.org/downloads/nem/de/nem111_d.pdf
https://www.morop.org/downloads/nem/fr/nem103_f.pdf
https://www.morop.org/downloads/nem/fr/nem111_f.pdf

Can we have all that in Old Money, please????  

[Northroader]

Get Brexit done, eh, Jordan?

[F-UnitMad]

1 hour ago, Northroader said:

Get Brexit done, eh, Jordan?

Yeah - never mind the consternation caused when Britain nearly joined the Euro - some are still fuming over Decimalisation....