British Z (1:220)

[The Nth Degree]

Theoretical work continues on the Z project, but existing standards are not satisfactory for what we are planning. To overcome this shortfall a whole new approach is required, starting from the relationship between wheel and track. In effect, what we're proposing is Z Fine. Here's a comparison between existing standards, accurate scale, and what we're proposing:

 

 

A fairly good halfway house.

 

Developing a potential new standard is opening up a lot of opportunities, especially in regards to control. For example, current Z control systems are 10V, but why not 9V, or even 5V so it can be run from USB? Imagine plugging in a whole layout to your computer, opening up an app and away you go – complete control from your desktop or tablet. USB has a data protocol built in, so could be adapted for use. Limited (milli)amps requires a very efficient electrical network and usage, so this will be the next challenge.

[Colin_McLeod]

The problem is that British stuff would be too small to fit on Märklin underframes in 1:220 so you would have to increase the scale to compensate.

Please let's not go there. It happened before and we got 4mm OO instead of 3.5mm HO.

 

I can just see the frothing in 50 years time when Peco announce the Z(large scale) correctly spaced sleepers with bullhead rail.

[Skinnylinny]

While USB does provide for data transfer, it does this using four wires: Power +, Power -, Data + and Data -. Sadly, unless modelling a four-rail system such as the London Underground, you won't be able to get data transfer and power over two rails with USB. DCC handles this by effectively putting the data onto the power connections. There's no reason you couldn't only use the power from a USB cable to power model trains, however, as long as it doesn't exceed the power capacity of the connector on the computer: most USB (v.1) sockets on computers are only able to supply up to 500mA at 5V.

[Vanders]

I wouldn't worry too much about USB. Finding some way to make existing DCC systems work (making the decoders fit, basically) seems like it would be a better idea for a "serious" model.

 

I'd like to say I'm also amazed at quickly you seem to be moving. It all seems very exciting, I can't wait to see what you've got up your sleeve!

[MissWeeble]

Whilst The Nth Degree is working on the electrical and control systems, I'm working on the practicalities of micro engineering mechanical systems and fitting both electrical and mechanical systems into a 50 x 11 mm space ! 

[Vanders]

Whilst The Nth Degree is working on the electrical and control systems, I'm working on the practicalities of micro engineering mechanical systems and fitting both electrical and mechanical systems into a 50 x 11 mm space ! 

50mm, you say? If my math is correct....well, that would certainly be nice!

[frobisher]

While planning I've stumbled upon a query and possible problem; couplings. Would modellers in this scale want to regularly couple/uncouple individual wagons or coaches. My guess is probably not, and it's far more likely to organise stock in pre-designated trains – I would imagine shunting in such a small scale would present many problems on its own, with couplings being the least of them. There are several types anyway, so which would one choose?

 

It would be far easier to design a proprietary loco-based train uncoupler rather than individual vehicle uncouplers. But I welcome any thoughts.

I would suggest grabbing something "off the shelf"

 

https://www.micro-trains.com/index.php?_route_=z-scale/couplers

 

No need to solve an already solved problem

[MGR Hooper!]

I would suggest grabbing something "off the shelf"

 

https://www.micro-trains.com/index.php?_route_=z-scale/couplers

 

No need to solve an already solved problem

Seconded. Also much easier to get spares and alternatives.

[The Nth Degree]

Couplings, control and other technical problems can't be tackled until the basics are sorted. The most obvious of those is the relationship between wheel and track, and as mentioned earlier, the current standard is rather course.

 

Rail is one supply problem, and one that I'd rather not solve, but as I now have an ideal railhead width of 0.5mm maximum we can source anything that exists already. There is a supply in the US, but I prefer something closer to home, and a possibility does exist.

 

Next, wheels and current collection. Anything this small will suffer disproportionately with friction, so a split frame/axle solution is the better bet by far. No rubbing pick-ups to worry about. Looking at diesel loco wheels in particular, at this scale we can pretty much produce just one size without any noticeable differences in variances in A1A bogies, for example, or between prototypes.

 

 

If we assume the above is the standard we are aiming at we can then design the track system to accommodate. Being all new means we don't have any legacy track systems to marry up with.

Edited January 23, 2018 by The Nth Degree

[2mmMark]

Happy to share my experiences of working in Nn3 where I've achieved some reasonable results. Marklin chassis do have some issues but these are not insurmountable.

http://www.rmweb.co.uk/community/index.php?/topic/57215-an-clr-2mm-scale-65mm-gauge/?hl=%2Ban+%2Bclar

 

The difficulty has been reliance on a single manufacturer Marklin for all the powered and unpowered donor chassis.  This is changing now other manufacturers have entered the market in the US and Japan.  Rokuhan have recently announced a keenly priced "shorty" bogie driven chassis which has potential for becoming an adaptable power unit.

http://www.rokuhan.com/english/news/2017/10/introduction-of-z-shorty-from-rokuhan.html

 

A  friend of mine in the US designed the Powermax drive unit marketed by Searails

http://www.searails.com/

This is  a very compact and smooth running little motor bogie and is used power a range of small N, Nn3 and Z locos.

 

To my knowledge, there have been few attempts to produce British items. The early 1980s saw some bodies produced to go on a Marklin chassis, I think there was a 47 & an HST. I also saw an etched kit for an RCH wagon but it was quite expensive at the time.

 

Brian Yallop built a couple of GER region layouts in Z scale. These have been featured in the Railway Modeller.

 

Brian Harrap, who's an RMWeb member has worked in Z finescale.

 

For expediency, I've stuck with the Z scale standards but built my own track with code 40 rail.  It is encouraging to see thought being given to a consistent rail and wheel standard.

Edited January 23, 2018 by 2mmMark

[2mmMark]

I should also add that the Microtrains Z wheelsets are much finer than the Marklin equivalents, albeit moulded Delrin.  There are equivalent metal wheels available from Fox Valley

http://www.foxvalleymodels.com/NWheels.html

[The Nth Degree]

Thank you Mark, your layout and stock is absolutely lovely!

 

I've seen Mr Yallop's layouts before – very well modelled. I'm sure I remember seeing a J15? It looked like the boiler was made from the motor barrel. I will have a look for Brian Harrap's work and see if we can have a chat.

 

Thank you for the info and links.

Steve

[The Nth Degree]

While compatible track geometry is being worked on, attention turns to drivetrain friction and current collection.

 

We now have a couple options on motor choice, both virtually friction-free, but more about those another time. We can design a gearbox similar to what we have designed for our recently announced Class 22 – it's compact and very efficient. Acetal gears running on stainless steel rod will be as good as or better than micro ball bearings, plus take up less space (see the bogie below to illustrate how even the smallest ball bearings are very large at this scale).

 

We are looking at a number of methods to carry the reduced drive to the bogies, so more about that another time, but drive will be transmitted to the inner axles of the bogies. We also working on axle-to-axle drive too, with worm gears and belts an option, along with a micro compound geartrain. Axle bearing friction is the last efficiency problem in the chain, and as you can see, bearings are possible using the 1x3mm type, but take up a lot of Y elevation of the bogie block, forcing it to be larger than it needs to be. This will make covering it with accurate cosmetic bogie frames more difficult – probably impossible.

 

 

The solution we will be testing is a graphalloy sleeve/bushing. This has several advantages: carbon alloy is very low friction and self lubricating, so presents maintenance-free operation. Bushings can be made much smaller than bearings, enabling a much more prototypical bogie frame height. Finally, and importantly, it carries current so allows pick-up from the bogie frame and not friction-based types on the wheel. To complete the bogie frame construction, the two sections are fixed together with nylon screws with an insulator at the joins.

 

While this theoretical work continues I'm very keen to hear feedback and any improvements to the design of the components as we go.

 

Thanks, Steve

[2mmMark]

One of the things I need to do regularly to ensure reliable running of my Z gauge mechs is remove the dust/fluff/crud buildup around crankpins and pickups. The graphalloy solution looks like it'll be less prone to collecting this buildup than the ball bearing option and easier to clean when its present.  It will build up, that's inevitable.

 

Pickup adjustment is also critical to good running. If this can be dialled out of the equation so much the better.

 

The Marklin gear train is all steel.  Robust but dependent on lubrication to avoid wear.  Acetal gears are a good choice as they are self-lubricating to a large extent. However plastic gears on N scale models do have a reputation for splitting which I believe to be a result of incorrect tolerances.

 

Mark.

[The Nth Degree]

Agreed Mark. What we have done on the Class 22 gearbox is the have fixed stainless steel axles in the gearbox with the gears running loose on it (approx 0.1mm free play). There is no mechanical drip on the gearbox axles, so this pre-loaded compound stress on the (sometimes) fragile gears around the axle is eliminated. The only problem left to eliminate is torque on the teeth.

 

The motor we are using for this exercise has 25g/cm torque at the shaft, but this will obviously increase down the geartrain, so once we have worked out what this is once the geartrain has been designed we can then select appropriate materials.

[The Nth Degree]

Most of the bogie types have been designed now (three of which are below) so we can now get some test wheelsets machined for testing. The test track is also being built, so hopefully in a couple months the main elements of the new standard will have been tested and trialled for final specification. After this we can gradually reduce track radius until each bogie falls off so we'll also know our limits in that respect too.

 

[Stevelewis]

I used  Markin Z Gauge  for  a few  years  as a diversion from my main interest in those  days  which  was  Garden Railwaying,  I had a 15' long by approx 12"-15" wide layout along one wall of a spare room, very unobtrusive  and it  really allowed  for  a  railway in the  scenery,

The Marklin locos  mostly  ran well  after  i had disposed of  the  smaller  ones! by h\that I mean small 0-6-0s etc  where pickup  did become a problem frequently, the 'larger' locos with  multi wheel pick up generally ran well, I found that Plastic bodied locos were obviously poorer  performers  than  the metal bodied ones due to adhesive  weight, Also metal bodied locos  ran more  quietly.

 

The  marklin style couplings  worked  fine  but uncoupling & shunting  etc was not very pratical  and I ran trains in fixed  formations.

 

One  thing to consider is * trackwork,  currently  Peco  supply flexible track only,  Markilin do a range of  points and a double slip and a range of setrack,  which I found to be around 85% OK

Japanese company Rokuhan  supply  a Range  Of  Kato UnItrack style  setrack which I beleive to be reasonably good  (but  checkout  the  cost on Gaugemaster website)

Rokuhan also produce a range of Japanese outline locos & rolling  stock.

 

If UK outline Z became  avaiable I would  consider  giving it a go!

 

I suppose  the   company name  would  have  to be ' The ​ TINY  Railway Company'.

 

* I believe Atlas may  produce some Z Gauge  trackwork also

Edited February 6, 2018 by Stevelewis

[The Nth Degree]

Ha! Indeed... They are really, really small.

 

We are working on track at the moment, and are a tandem development with the wheels. I'm sure he won't mind me saying, but Martin Wynne is developing some pointwork in prototypical style. We're just about to have a series of B7s produced for the test track, and will go to smaller sizes later to see where we can get to.

 

Stay tuned, it's going to take a couple years to come to fruition, but plans are way in advance of what I'm writing here, and there are some very good surprises to come!

[Stevelewis]

The  Company name of  the  manufacturer of  the Class 47 & HST 125 bodies, back in the  olden days  was  ELLMAR  Products  If I recall correctly

[MissWeeble]

Designing in 1:43.5 and 1:220 is interesting, its surprising the amount of detail that can be transferred to the smaller scale with some thought ! 

[Dava]

How about a Ruston 48DS in Z gauge? That could be popular now the Gauge 0 version has gone tits up.

 

Seriously, I have the original GCR 'Bridge to the Future' foamboard architects model in my workshop, 7ft of Z gauge track. All I have to put on it is a static Atlas Gresley A4 and diecast coaches. They also did an A3. An operational UK Z gauge train could lead me to upgrade the model to running condition and take it out there for events where our n gauge model is too big - such as Tornado running on the GCRN this weekend.

 

Dava

[The Nth Degree]

Ha! The 7mm Ruston is not cancelled yet, just sorting production 'issues'... I should have just kept production in China.

 

I doubt very much we could produce a Z Ruston - at least not a working model. Even in 7mm the bonnet is only 20mm wide and only just wide enough for the motor and some of the gearbox. I'd like to see a couple pictures of your architects model though. I've built a few of those myself in my uni days, usually to 1:200 scale.

 

We hope by the time these Z models are released they will be produced in our own factory. The only outsourced product will be the motors. Any delays at this point will definitely be only our fault!

[Dava]

Here is a photo of the GCR 'Bridge' architects model to Z scale, made in 1995, mainly from foamboard. The Midland mainline bridge is to the left.

 

 

It was likely to end up in a skip last year during a clearout at the GCR HQ, so I have saved it in my workshop for the time being as a piece of history. It could be renovated and updated for display in future, if we have somewhere to show it.  I sourced an Atlas A4 and train to put on it, quite crude models but OK for $20. Even getting all the wheels on the rail is chancy!

 

 

The Peco Z gauge rail is IL1/code 60, also sold as 00 gauge '3rd rail' and I use it for my 014 narrow gauge layout for which its ideal. Rather overscale for Z scale though! Sounds like LLC have plans for this? Maybe the model could even showcase a LLC prototype in the future?

 

For comparison, I rebuilt the later N gauge 'Bridge to the Future' model last year to represent the new bridge designs and to be an operating layout. It will be at Nottingham exhibition on 16-17 March, so call by the Friends of the GC MainLine stand if you're there. More details of the layout and project here:  http://www.rmweb.co.uk/community/index.php?/topic/99474-great-central-railway-news/page-15

 

Dava

[The Nth Degree]

That's very interesting. Takes me back a few years too! It would look great with some colour and texture.

[The Nth Degree]

I've updated the bogie types planned so I don't have to make so many compromises in wheelbase. As long as any one design caters for more than one prototype it would be efficient to produce it. You'll notice that the Class 52 Western is not listed, for example, so unless this would be a really good seller (which is probably likely) it would not cover development and manufacturing costs of a unique bogie – each of which is very expensive to produce, despite being very small. This is an updated list:

 

 

And, chosen at random, some examples of what they would look like in models:

 

 

In the top picture you can see the development stage of the bogie mount. This scale is very deceptive – despite the mounting spigot looking enormous, its diameter is only 2mm! Totally different to designing in 7mm scale.