Mainly Diecast steam loco bodies

[34theletterbetweenB&D]

Of what I have purchased of Hornby's product, supplemented by information provided by @maico, 'current' Hornby have now released at least 8 steam models with largely cast metal bodies: Schools, Adams Radial Tank, 700, B12/3, D16/3, J15, J36; and most recently the Dublo commemorative Duchess. (Any further additions?)

 

On tender locos I have seen, the construction is typically footplate, boiler and smokebox all cast, plastic used for the cab and various applied detail components. Assembly is very neat, and 'cast-in' detail such as bolt or rivet heads are fully equivalent the finesse achieved with injection moulding, such that the different materials under the paint finish do not draw attention to themselves.

 

The benefit for traction is significant, the extra weight from near all metal construction pays off handsomely, to the extent that the B12/3 - which is a petite 4-6-0 - outdoes all other RTR 4-6-0s I have to compare with. This is most useful on smaller subjects where there is a lack of internal volume to pack in ballast inside a plastic body shell. My personal bete noire among RTR OO models is Hornby's 8F; the combination of a dated less than elegant mechanism layout and the consequent limited interior space resulting in a visually flawed model also lacking in traction. (My fix of the old H-D diecast body on the current model mechanism is at least adequate for traction, but the intrinsic flaws in appearance remain. One of Sir William's finest deserves better.) Side note, the Oxford Rail N7 with footplate, side tanks and bunker all in cast metal delivers in much the same style.

 

As you may gather I am all approval and would like more of the same. I am also somewhat surprised that this construction is not actively promoted by Hornby: the price is the same, for a superior construction.

 

Against which of course, some may feel there are disadvantages, or simply not like the idea; and that would be interesting to know.

[The Johnster]

The decision to use die cast is probably made by production engineers and is in practice more to do with ease of production and keeping costs down than increasing haulage capacity.  There seems to be no intrinsic advantage to metal or plastic toolings, both can be produced with a high level of detail.  
 

But the choice does affect haulage.  It is my contention that most plastic bodied RTR steam outline models are far too light and incapable of prototypical performance as a result.  A pacific should be able to haul 14 bogies at a scale 80mph on the level, but I doubt any of the plastic bodied RTR ones  can.  I doubt a plastic bodied 8F could handle 60 loaded wagons at scale 45mph either. Therefore I agree in principle, but  there are other factors at play.  The great majority of us do not have the space to run such trains, which are over 17’ long with the loco, assuming scale couplings. 
 

Moreover, the great majority of us use curves of insanely low radii in scale terms, and this has a significant impact on the ‘drag’ of a train, even assuming that all wheelsets are running perfectly freely and that all chassis are perfectly square and level, as are all bogies, which all move freely on their pivots.  I haven’t even begun to consider gradients 

 

So, for most of us it doesn’t matter; for example, I have a Hornby 42xx (second tooling, not ‘design smart’) which I very much doubt could haul 30 loaded minerals never mind 60.  On my layout she pootles about with 12 loaded, all I’ve room for.  Like all my locos, I’ve put as much ballast in her as I can over the driving wheels, but...

 

[Steamport Southport]

I think you are seeing a problem that doesn't exist. Most of them have big chunky, heavy chassis which makes up all the necessary weight. Some of the smaller models need a bit more weight so they get it.

 

 

No problem with the normal Hornby Duchess or any of the other recent large express passenger locomotives pulling 14 RTR coaches at speed.....

 

They may struggle with heavy kit built stock, but wouldn't you be building kit built locomotives to pull them if you needed to?

 

Can a Hornby 8F pull 60 wagons? No idea as I don't have one. But other large 2-8-0s and 0-8-0s can easily. Just ones I've got - Bachmann ROD and normal O4, G2, Heljan O2, Hornby O1, 

 

Plenty of videos on YouTube showing them doing just that.

 

As for the diecast Duchess I feel it looks crude. Look at the rivet detail particularly around the smokebox and cab roof sides, it's far too prominent. The normal version looks a lot finer.

 

Prickly pear is an apt description.

 

 

 

Jason

Edited August 11, 2020 by Steamport Southport

[maico]

40 minutes ago, The Johnster said:

The decision to use die cast is probably made by production engineers and is in practice more to do with ease of production and keeping costs down than increasing haulage capacity.  There seems to be no intrinsic advantage to metal or plastic toolings, both can be produced with a high level of detail.  
 

But the choice does affect haulage.  It is my contention that most plastic bodied RTR steam outline models are far too light and incapable of prototypical performance as a result.  A pacific should be able to haul 14 bogies at a scale 80mph on the level, but I doubt any of the plastic bodied RTR ones  can.  I doubt a plastic bodied 8F could handle 60 loaded wagons at scale 45mph either. Therefore I agree in principle, but  there are other factors at play.  The great majority of us do not have the space to run such trains, which are over 17’ long with the loco, assuming scale couplings. 
 

Moreover, the great majority of us use curves of insanely low radii in scale terms, and this has a significant impact on the ‘drag’ of a train, even assuming that all wheelsets are running perfectly freely and that all chassis are perfectly square and level, as are all bogies, which all move freely on their pivots.  I haven’t even begun to consider gradients 

 

So, for most of us it doesn’t matter; for example, I have a Hornby 42xx (second tooling, not ‘design smart’) which I very much doubt could haul 30 loaded minerals never mind 60.  On my layout she pootles about with 12 loaded, all I’ve room for.  Like all my locos, I’ve put as much ballast in her as I can over the driving wheels, but...

 

 

Can't agree with that first paragraph. If you watch some of the factory tour videos taken at Roco and Marklin-Trix on youtube, it's clear die-cast is the far more expensive option. Plastic comes out of modern machinery remarkable clean. Metal needs hand fettling with a file and further CNC processing.

 

Here's the new 2020 Hornby MT-2. Die-cast running board and boiler. The metal work is not up to Marklin-Trix standards but looks very good given the money being asked

[The Johnster]

Good example of what can be achieved in cast metal, an excellent result.  There will be a reason that H chose die cast metal for this loco despite the post-casting manual work needed, though.  I’m not a production engineer, which is probably a relief both to me and any company who might employ me in such a role, but perhaps die casting on this model saves an operation later in the process, or has some structural role to play (that running plate is not the world’s thickest), but you can bet my entire pile of clean socks the decision is made on overall cost grounds. 

[34theletterbetweenB&D]

13 minutes ago, Steamport Southport said:

...Can a Hornby 8F pull 60 wagons? No idea as I don't have one. But other large 2-8-0s and 0-8-0s can easily. Just ones I've got - Bachmann ROD and normal O4, G2, Heljan O2, Hornby O1...

It was joint poorest for traction from that selection, equivalent the G2, which is only 6F - I have the exact same set to compare with - and while I could get it hauling 60 on level track by careful selection of only sub 30g current RTR wagons running empty, it will noticeably slip with such a train fully on a 180 degree curve, radius 30" or greater. (The mechanism is more than adequate, with the old H-D body substituted, it's equal in weight and traction with the hefty Heljan O2.)

[Bernard Lamb]

4 hours ago, Steamport Southport said:

 

 

As for the diecast Duchess I feel it looks crude. Look at the rivet detail particularly around the smokebox and cab roof sides, it's far too prominent. The normal version looks a lot finer.

 

Prickly pear is an apt description.

 

 

 

Jason

Is not that the whole point?

This is a limited edition aimed at collectors and is a celebration of the history of models of the class.

Normal expectations do not apply.

Bernard

[maico]

11 hours ago, The Johnster said:

Good example of what can be achieved in cast metal, an excellent result.  There will be a reason that H chose die cast metal for this loco despite the post-casting manual work needed, though.  I’m not a production engineer, which is probably a relief both to me and any company who might employ me in such a role, but perhaps die casting on this model saves an operation later in the process, or has some structural role to play (that running plate is not the world’s thickest), but you can bet my entire pile of clean socks the decision is made on overall cost grounds. 

 

Sam's Trains put a ruler up to the plastic running board of his new Hornby Large Prairie. It looks warped at the front.

At the very least that part should be die-cast metal IMHO

Edited August 12, 2020 by maico

[The Johnster]

The ruler is not level; scroll the picture down to the bottom of your monitor screen if you don't believe me.  It is rising towards the front and the running plate seems level enough to me, bearing in mind that there is a parallax issue and and the track is not perfectly level in the image frame either.  But it does do strange things to your perception in conjunction with the taper boiler, doesn't it?

 

I believe Hornby were in some trouble with warped running plates with the 42xx/52xx/72xx models, though my 42xx is fine.  

[maico]

11 hours ago, The Johnster said:

The ruler is not level; scroll the picture down to the bottom of your monitor screen if you don't believe me.  It is rising towards the front and the running plate seems level enough to me, bearing in mind that there is a parallax issue and and the track is not perfectly level in the image frame either.  But it does do strange things to your perception in conjunction with the taper boiler, doesn't it?

 

I believe Hornby were in some trouble with warped running plates with the 42xx/52xx/72xx models, though my 42xx is fine.  

 

You can clearly see a bend at the 5.06min mark starting just after the water tank. The running board bends down from there!

 

 

Edited August 12, 2020 by maico

[The Stationmaster]

Diecast metal is clearly much more expensive than plastic because it requires harder metal tools, which cost more for material, and more to actually turn the metal into moulds because  it is harder to cut.  I somehow doubt that aluminium moulds - a well known cost saver for producing moulds for plastics - can be used for diecasting metal components in any sirt of quantity if they can be used at all.  However precision metal moulding appears to be a common thing in China as it has been developed for other, far larger than model railways, customer industries.   A Kader Group subsidiary mould making company apparently produces moulds suitable for metal diecasting although they seem to be entirely for the automotive industry and Kader do not note the factory concerned as producing anything for their model railway businesses.

 

On a very different matter the 'kink' in the latrge prairie running plate apprears to be connected with poor assembly of the motion bracket and is not present on every model.  I looked at three in my local retailer's display case a couple of weeks ago and they all had straight running plates

[maico]

The pre-decorated sample looks fine.

[maico]

I had the metal body off my Trix German P10 the other day to check what type of motor it has (Portescap Athlonix coreless), and the shell comes in at 160 grams. So, not a super heavy model at 475g with tender, but one that feels a real precision product in hand. 

The way the body screws fit perfectly suggests Marklin-Trix are working to higher tolerances than most I've come across.

Edited August 12, 2020 by maico

[Nearholmer]

Die-casting seems to be being advocated here as the answer to the maiden's prayer when it comes to warping problems.

 

Go carefully on that front, because badly-designed/processed die-castings warp during cooling.

 

I would suggest that warping isn't a function of the material (non-engineered timber aside), but a function of design, or some stage of production, possibly in combination.

 

As regards the detail achievable with good die-casting, it is excellent. As a follower of coarse-scale 0, a lot of my modern-made locos incorporate diecast parts, some very large, and some very detailed, and the specialists in China really know how to do this stuff - I'd be interested to see their moulds, because the shapes are such that the must be using either very dense, very high-temperature synthetic rubber, or very complex multi-part moulds, to allow the workpieces to be extracted.

 

A US-designed, Chinese made beast happens to be to hand. nearly everything you can see is a series of die-castings.

 

 

 

Edited August 12, 2020 by Nearholmer

[34theletterbetweenB&D]

1 hour ago, The Stationmaster said:

However precision metal moulding appears to be a common thing in China as it has been developed for other, far larger than model railways, customer industries.   A Kader Group subsidiary mould making company apparently produces moulds suitable for metal diecasting although they seem to be entirely for the automotive industry and Kader do not note the factory concerned as producing anything for their model railway businesses...

And from Kader, at the start of Bachmann's 'Blue Riband' programme, we have seen a diecast metal footplate in most (possibly all? - I haven't inspected every release) tender loco body constructions. (One step further on, the A1 and A2 pacifics, the cab is cast metal too.) No serious objections of crudity arising in the twenty or so years this has been going on, and it was a good start toward producing heavier RTR OO steam models.

 

While there may be some higher materials costs in tooling for diecast as compared to injection moulding, improving technique has probably narrowed the cost differential; and polymer prices are only trending in an unfavourable direction.

 

And per @Nearholmer of course this is no panacea. Confers a major benefit of increased mass, especially valuable in smaller models; but there will inevitably be issues to be solved. 

[The Johnster]

2 hours ago, The Stationmaster said:

 

On a very different matter the 'kink' in the latrge prairie running plate apprears to be connected with poor assembly of the motion bracket and is not present on every model.  I looked at three in my local retailer's display case a couple of weeks ago and they all had straight running plates

Which brings us back to the issue of Hornby's QC.  If the motion bracket is poorly assembled but not in itself malformed or misshaped, one can presumably rectify this by carefully taking it off and refitting it properly, but many will feel uncomfortable with this and it should not be necessary on a new model.  But it is disturbing, since the failure of the motion bracket and slide bar assembly is what did for both of my ancient Airfix large prairies and has dissuaded me from buying later  s/h Hornby versions which, while they have improved mechs over the Airfixs', retain the same tooling for this assembly and will evenutally fail in the same way.  

 

Oh, well, the large prairie's not high on my shopping list, a loco I'd like rather than want or need.

[maico]

Marklin gauge 1 locos are die-cast zinc alloy. The body shell is massive on the SNCF 241 and so is the cost. Many of the separately applied parts are brass.

https://www.maerklin.de/service/produktservice/listengenerator.php?brand=1&artikelnummer=55082&lang=1

 

 

Edited August 12, 2020 by maico

[PenrithBeacon]

The problem with mazac is the if there's an error it's much more difficult to fix. The classic one is oversized splashers, a complete pain.

[Steamport Southport]

On 11/08/2020 at 19:05, Bernard Lamb said:

Is not that the whole point?

This is a limited edition aimed at collectors and is a celebration of the history of models of the class.

Normal expectations do not apply.

Bernard

 

But the Hornby model was mentioned in the OP as the direction Hornby should be going.

 

I very much disagree. There is already a fantastic Duchess in the range. Why go backwards?

 

 

Maybe there is demand for a "Hornby Dublo diecast" range with models such as the A4 and Castle. More like a better version of the Railroad range for the oldies and collectors.

 

But please keep it totally separate from the normal models....

 

 

 

 

Jason

[Bernard Lamb]

13 minutes ago, Steamport Southport said:

 

But the Hornby model was mentioned in the OP as the direction Hornby should be going.

 

I very much disagree. There is already a fantastic Duchess in the range. Why go backwards?

 

 

Maybe there is demand for a "Hornby Dublo diecast" range with models such as the A4 and Castle. More like a better version of the Railroad range for the oldies and collectors.

 

But please keep it totally separate from the normal models....

 

 

 

 

Jason

The Duchess is totally separate from normal models.

The quality of the die cast components in the other models is of a very different standard.

You say "Why go backwards?"

If 500 plus people will buy the Duchess at what is I presume a higher than normal mark up then I am happy, as it should provide security of production for what I want to purchase.

It would seem that in all the other models mentioned the use of metal rather than plastic has been done to actually improve the models. Basically I think we agree with each other.

Bernard

[aaron3820]

A lot of the issues people have with locos not being able to haul large loads (in my mind at least) actually stems from the fact that their rolling stock isn’t maintained properly or is simply too heavy. Bachmann mk1s for example nearly weigh a ton each (slight exaggeration) and aren’t the most free wheeling models out there, so when you times that by a factor of 10+ the amount of effort a loco needs to put out just to move a train on the flat is immense. 

[No Decorum]

21 hours ago, maico said:

Marklin gauge 1 locos are die-cast zinc alloy. The body shell is massive on the SNCF 241 and so is the cost. Many of the separately applied parts are brass.

https://www.maerklin.de/service/produktservice/listengenerator.php?brand=1&artikelnummer=55082&lang=1

 

Very impressive. I thought I’d check the price. £4,000·00.  I don’t think I want to go in that direction!

[maico]

They make a nice Swiss Croc gauge 1 which can be picked much cheaper on the used market. Unboxing it is a major feat of engineering...

 

 

[Talltim]

59 minutes ago, maico said:

They make a nice Swiss Croc gauge 1 which can be picked much cheaper on the used market. Unboxing it is a major feat of engineering...

 

 

Want one. 

[The Johnster]

9 hours ago, aaron3820 said:

A lot of the issues people have with locos not being able to haul large loads (in my mind at least) actually stems from the fact that their rolling stock isn’t maintained properly or is simply too heavy. Bachmann mk1s for example nearly weigh a ton each (slight exaggeration) and aren’t the most free wheeling models out there, so when you times that by a factor of 10+ the amount of effort a loco needs to put out just to move a train on the flat is immense. 

This is a very good point, and should be considered along with tracklaying and baseboard building.  We all do our best and I reckon I’m not bad at level baseboards and track pieces joined smoothly and level to each other, to which I attribute the good running on Cwmdimbath, but no loco will haul it’s potential best on wavy ‘dip in the middle peak at the ends’ boards or anything but meticulously laid track.