Generic chassis

[tomparryharry]

I've bought this 'side discussion' over from the Hornby thread, to hopefully give it some space of its own.  Part of the discussion centred on the provision, or lack of, pre-grouping locomotives. A fair few modellers would like to have RTR examples of their 'pet' railways, but being a niche market, makes the prospect unlikely. 

 

However... Nearly all of the smaller-pre-group railway companies went to outside builders for their locomotive stock. Even the mighty Taff Vale Railway, which could build their own locomotives, went 'outside' because the traffic demands were so high. Smaller railways, such as the Cardiff, went to Kitsons for their 'off the peg' locomotives. 

 

Which brings us to 'off the peg' locomotives. Or, if you wish, generic locomotives. It would appear that each & every Railway company had its own 'house style' It might be operational requirements, aesthetics; any number of things. However, once you go below the footplate level, things start to take on a degree of uniformity & standardisation. In real terms, they had to be standard; mechanical processes will closely follow proven formulae, especially inside cylindered  steam locomotives with Stephenson valve gear. For a fairly late-Victorian inside cylinder locomotive, it's a 2-cylinder 0-6-0, with wheels of about 4'6" (goods), up to 5'2" for passenger work. Leading or radial trucks are optional.  Suddenly, the niche is not quite so niche, is it?

 

Moving across to RTR, we could now end up with a generic chassis, 0-6-0, based upon a fairly standard wheelbase. This allows more serious modellers to take it out to EM, or P4. I've very deliberately omitted compensated chassis, this is still in what is normally RTR territory. It can't really be 100% accurate to the Nth degree, but you could take it the last steps (P4, etc). Naturally, thing like chips (Hmm, I like chips)  and sound (Hmm, I like the sound of chips) are outside of this little topic. 

 

So, if a business (let's say, Hattons, etc) can produce 'generic' coaches, how about something like a Generic RTR chassis? Anyone for a North Stafford loco?

 

Happy modelling,

Ian. 

 

 

[melmoth]

Disclaimer: it's Sunday, and I have lunched well. Therefore, any opinions I express may well be completely wrong. And/or vaguely incoherent.

 

I don't think that this idea would hold much attraction for P4 modellers - wheel profiles for one thing, arguable need for compensation, & number of spokes per wheel perhaps?

 

Wheelbase is a potential sticking point - the Hornby 2721 Pannier can be made to look quite good, but the chassis always seems wrong because it is a generic product.

 

A 7' 6" + 8' 6"  (IIRC) 0-6-0 chassis might be useful for building a lot of Midland engines, but would that work for any other pre-grouping company?

[tomparryharry]

1 minute ago, melmoth said:

Disclaimer: it's Sunday, and I have lunched well. Therefore, any opinions I express may well be completely wrong. And/or vaguely incoherent.

 

I don't think that this idea would hold much attraction for P4 modellers - wheel profiles for one thing, arguable need for compensation, & number of spokes per wheel perhaps?

 

Wheelbase is a potential sticking point - the Hornby 2721 Pannier can be made to look quite good, but the chassis always seems wrong because it is a generic product.

 

A 7' 6" + 8' 6"  (IIRC) 0-6-0 chassis might be useful for building a lot of Midland engines, but would that work for any other pre-grouping company?

 

A valid point on your behalf. I will enquire, however, whether your perception is based upon comparison between a 27xx pannier, and the Bachmann version? We would know, for instance, that putting a Baccy chassis under a Lima 94xx improves the older models' look dramatically.  The 27xx will always look wrong, as it's a straight throwback to the 1950's Triang Jinty. 

 

I will respectfully say, however, that I did deliberately pitch this at-as  an RTR product. As far as a coupled wheelbase is concerned, then it will be down to the modellers personal requirements.

 

Cheers,

Ian. 

[Wheatley]

It can certainly be done, witness your 27xx Pannier/Jinty/08/Thomas (any more ?) chassis. Whether there are enough people capable of putting a kit together who would want to plonk it on a generic chassis is another matter - I wouldn't unless the wheelbase and appearance of the wheels was spot on, I'd sooner kit build. 

 

Wheelbase and wheel diameter would be my greatest sticking points - on a tender engine they can throw the relationship between the cab front and middle splashers out by quite a lot, less noticeable on a tank loco. 

[melmoth]

Yes, I've done the 94xx conversion, though the 2721 chassis is actually the version first issued in 1978 (?) under the 'revised' Jinty and then the LBSC E2 and 2721 (and possibly also the J83 and J52), rather than the original 1950s Triang chassis.

 

Surely though, leaving EM and P4 aside, of all the things on a RTR chassis the wheelbase is the hardest to change?

Edited July 26, 2020 by melmoth
confused reference to something called 'EM4'

[34theletterbetweenB&D]

1 hour ago, melmoth said:

...A 7' 6" + 8' 6"  (IIRC) 0-6-0 chassis might be useful for building a lot of Midland engines, but would that work for any other pre-grouping company?

For 0-6-0 tender locos there are two well known common sets of dimensions that were settled in the 1850s.

Derby settled on 8'+8'6" for its 0-6-0s, and that was taken up by other railway company works.

Crewe settled on 7'3"'+8'3" for its 0-6-0s, and that was taken up by other railway company works.

(Triang's ancient compromise of 7'9"+ 8'3" thus democratically similarly in error for both.)

Many railway company works had their own formula, but somewhere in the 15' to 17' range was generally typical in the second half of C19th.

 

No idea at all what the private builders ranged over, and of course they may have followed customer requests. Obviously different, the early 'Stephenson long boiler' format which had the rear axle moved closer to the crank axle to provide for the ashpan behind the rear axle; no idea when the last such was constructed.

 

I would cautiously suggest that the present array of wheelbase choice in RTR OO six coupled mechanisms with wheel diameters scaling 4' 7" - 5'4", which definitely offers 7'3"+8', 7'3"+8'3", 7'3"+9', 7'6"+7'9", 7'6"+8', 7'6"+8'9", 8'+8'6", 8'1"+9'; probably doesn't leave much opportunity for a generic layout: unless there is something very differently proportioned that saw significant use.

[CKPR]

I've long thought that a 4mm model or, more likely, a kit, of one of the more commonly used standard designs of 0-6-0 from Kitsons / Beyer-Peacock or Sharp Stewart would be a more viable proposition e.g. the  Sharp Stewart 'sharpie'  0-6-0 used by the Cambrian and Furness or the Kitson / Beyer-Peacock engines supplied to the Taff Vale and L&Y along with very similar engines supplied to the M&CR (the later is of course already made by London Road Models). That NSR locomotive might come via a standard  NBL design that was supplied to the Knotty, as  well as the FR and also seemingly to the G&SWR and the M&CR.

 

[Wheatley]

Caledonian 0-6-0s varied between 7'6"+8'9" and 7'9"+9'0" with two different wheel sizes (4'6" and 5'0"), so that's three different chassis just for one company even if you ignore the different patterns of 5'0" driving wheels, none of them common to the Crewe or Derby dimensions.  Their 6'6" 4-4-0s managed three different wheelbases across 7 classes.

 

Even if you drop on a prototype which fits the generic chassis, unless you can do it for about 50-60 quid then a set of Gibson wheels and a decent mtor/gearbox combination becomes financially more attractive, albeit that that you have to assemble it yourself. 

[Legend]

3 minutes ago, Wheatley said:

Caledonian 0-6-0s varied between 7'6"+8'9" and 7'9"+9'0" with two different wheel sizes (4'6" and 5'0"), so that's three different chassis just for one company even if you ignore the different patterns of 5'0" driving wheels, none of them common to the Crewe or Derby dimensions.  Their 6'6" 4-4-0s managed three different wheelbases across 7 classes.

 

Even if you drop on a prototype which fits the generic chassis, unless you can do it for about 50-60 quid then a set of Gibson wheels and a decent mtor/gearbox combination becomes financially more attractive, albeit that that you have to assemble it yourself. 

 

Good points , but I think the last part "you have to assemble it yourself " is the key here .  A lot of people just don't have the skill set these days . I don't

 

I have often thought a generic 0-6-0 chassis might work if it were accompanied by body and tender kits of various locos .  Sort of like the Knock Down Kits that used to be done or Kitmaster/Airfix but with a reliable preassembled chassis . I had hoped that when Airfix and Hornby got together we might have seen something along these lines , but certainly not so far.

[298]

20 hours ago, tomparryharry said:

, if a business (let's say, Hattons, etc) can produce 'generic' coaches, how about something like a Generic RTR chassis? Anyone for a North Stafford loco?

 

Happy modelling,

Ian. 

 

 

 

Just because Hatton's are doing something generic doesn't mean it's a good idea, it means they have perceived a market for something that is of a better standard than the Hornby 4 wheeler and less effort than a Ratio coach kit. Things that require less effort definitely sell, which is why you don't see box shifters commissioning a run of un-numbered banger blue or large logo diesels for the purchaser to finish themselves.

[hayfield]

Back in the early days of whitemetal locos the old Triang  Jinty chassis was the generic chassis of kit makers, this had led to highly detailed etched chassis for either tank or tender versions from Southeastern Finecast which can be used to up spec RTR models.

 

Many chassis kits are available, Comet has many simple style chassis and High Level has some highly detailed ones

 

The whole range of Southeastern Finecast chassis are available separately, which covers many mainline types. CSP models are happy to supply all of their chassis which covers many industrial styles. I assume many other chassis kits are available from the likes of Branchlines and London Road models to name two 

 

No shortage of chassis available

 

 

Edited July 27, 2020 by hayfield

[Wheatley]

3 minutes ago, Legend said:

 

Good points , but I think the last part "you have to assemble it yourself " is the key here .  A lot of people just don't have the skill set these days . I don't

 

 

Agreed, my Caley Pickersgill 4-4-0 has a Hornby T9 chassis under it, it was easier than trying to hammer Nu-Cast's offering into submision. But if it's too generic a lot of the potential market won't be there. Don't get me wrong, if there was a generic chassis which fitted whatever it was I was building to within a mm of wheelbase and wheel diameter I'd buy it, but it would have to be that close.

[tomparryharry]

I started this little topic to see if there is indeed, any depth to this sort of thing. If there is enough 'want', then we can respectfully petition manufacturers to make said product. To expand a little upon my original post, it appears that 6-7 variations on the theme will-might cover a significant proportion of the intended market. 

 

Naturally, in certain subjects, you will go down the kit-scratchbuilding route, but I thought I'd open it out for polite discussion, and observations.  I did intentionally mention RTR, or did I leave that out?

 

I didn't expect the Spanish Inquisition!

 

Cheers,

Ian.

Edited July 27, 2020 by tomparryharry
Just checking text

[Legend]

It’s a good initiative Ian .  The problem is that with modern RTR being so good, if expensive , people have moved away from the “make do” generic chassis . I still think it’s a possibility. Let’s face it there are several locos that will  never warrant an RTR model but could be viable in kit form .  

Edited July 27, 2020 by Legend

[Captain Kernow]

19 hours ago, melmoth said:

Surely though, leaving EM and P4 aside, of all the things on a RTR chassis the wheelbase is the hardest to change?

Well, perhaps the real 'design clever' thing would be to market a chassis, on which the wheelbase could be changed, even if only a few mm. And perhaps a range of 'drop in', ready quartered driving wheels could be produced, which would allow further flexibility as to company etc.

 

Edited July 27, 2020 by Captain Kernow
Artistic emphasis, Darling.

[Wheatley]

The good Captain might be on to somthing here, Hornby's Black 5 accommodates the two different wheelbases by having a bearing with an off centre hole - put in one way you get short wheelbase, turn it round you get long wheelbase. A chassis block which is square and true (which is the other bit most folk struggle with after quartering) with one fixed driven axle, alternative bearings for the other two, some ready-quartered drop-in wheelsets and alternative coupling rods would get my vote.

 

I'm not averse to your idea Ian, but Legend is right. I'd settle for close (second best is close to ideal after all) but not Hornby's old "one size fits all even where it clearly doesn't" approach.

Edited July 27, 2020 by Wheatley

[Steamport Southport]

3 hours ago, hayfield said:

Back in the early days of whitemetal locos the old Triang  Jinty chassis was the generic chassis of kit makers, this had led to highly detailed etched chassis for either tank or tender versions from Southeastern Finecast which can be used to up spec RTR models.

 

Many chassis kits are available, Comet has many simple style chassis and High Level has some highly detailed ones

 

The whole range of Southeastern Finecast chassis are available separately, which covers many mainline types. CSP models are happy to supply all of their chassis which covers many industrial styles. I assume many other chassis kits are available from the likes of Branchlines and London Road models to name two 

 

No shortage of chassis available

 

 

 

And Alan Gibson do virtually every chassis imaginable. They used to do them as commissions as long as you provide a drawing or dimensions. I don't know whether they still provide that service.

 

 

 

 

 

Jason

[tomparryharry]

2 hours ago, Wheatley said:

The good Captain might be on to somthing here, Hornby's Black 5 accommodates the two different wheelbases by having a bearing with an off centre hole - put in one way you get short wheelbase, turn it round you get long wheelbase. A chassis block which is square and true (which is the other bit most folk struggle with after quartering) with one fixed driven axle, alternative bearings for the other two, some ready-quartered drop-in wheelsets and alternative coupling rods would get my vote.

 

I'm not averse to your idea Ian, but Legend is right. I'd settle for close (second best is close to ideal after all) but not Hornby's old "one size fits all even where it clearly doesn't" approach.

 

Quite, and that is why I used the word 'Generic'.

[tomparryharry]

49 minutes ago, Steamport Southport said:

 

And Alan Gibson do virtually every chassis imaginable. They used to do them as commissions as long as you provide a drawing or dimensions. I don't know whether they still provide that service.

Jason

 

My first post on this topic was directed at RTR 'Generic' chassis. If I want something exact, or niche, then I'll use the Gibson lists, which are quite extensive. 

 

Cheers,

Ian. 

[Steamport Southport]

1 minute ago, tomparryharry said:

 

My first post on this topic was directed at RTR 'Generic' chassis. If I want something exact, or niche, then I'll use the Gibson lists, which are quite extensive. 

 

Cheers,

Ian. 

 

I was adding to Hayfield's post as he had quite a list of chassis and those were missing.

 

 

I don't quite understand the thread. Is it RTR chassis for old whitemetal body kits such as Finecast or GEM?

 

As they are already available RTR in most sizes. The relevant ones for the kits would be Jinty, 57XX, J50, 4F, B12, A3, L1/4-4-0 equivalent, etc. 

 

Although why you would want to put an A3 chassis under a Royal Scot like it says in the Wills instructions I was looking at earlier seems a bit strange in 2020.

 

 

 

 

Jason

[34theletterbetweenB&D]

5 hours ago, Wheatley said:

The good Captain might be on to somthing here, Hornby's Black 5 accommodates the two different wheelbases by having a bearing with an off centre hole - put in one way you get short wheelbase, turn it round you get long wheelbase. A chassis block which is square and true (which is the other bit most folk struggle with after quartering) with one fixed driven axle, alternative bearings for the other two, some ready-quartered drop-in wheelsets and alternative coupling rods would get my vote...

Nice idea, but you also end up with a large heap of alternative parts that put the price up, coupling rods and pick up arrangements that are tied to wheelbase, and brake detail if that's to be included; and that's before you get to motor and gear train, which pretty much has to offer alternative low and high boiler centre line positions for the motor to enable concealment and some syetem of mounting points for the body. This activity is a minority sport to begin with, and increasing complexity  and putting the price up is only going to reduce uptake.

 

And on price, what would the acceptable price be? I am an enthusiastic 'stuffer' of current drives into older RTR and kit bodies. From this list in my earlier post:

On ‎26‎/‎07‎/‎2020 at 18:26, 34theletterbetweenB&D said:

7'3"+8', 7'3"+8'3", 7'3"+9', 7'6"+7'9", 7'6"+8', 7'6"+8'9", 8'+8'6", 8'1"+9';

there are only two I so far haven't transplanted, and that's just smaller six-coupled models, there are plenty of others I have used as well. For a 'smaller one' I might go as high as £30 for a 'generic chassis' offering dimensions combinations not available under current RTR; it rarely costs me that much for a mechanism by buying the donor on sale or s/h, and then selling off all the unwanted bits. Boxes alone can go for a fiver up...

[The Johnster]

So, there are two basic 'standard generic' axle spacings, Derby and Crewe, and 3 basic wheel sizes, 4'1", 4'7", and 5'2", or ball park.  Wheel diameters can be slightly under anyway to represent tyre wear; it's not an exact science.  2 basic kits, a Derby and Crewe, for the largest size driving wheels but with packing for the smaller sizes, with matching fluted coupling rods and fill in pieces to make plain coupling rods would suffice for a considerable number of 6-coupled inside cylinder locos.  To appeal to the market these should be supplied with the motor and gearbox fitted and wired to the keeper plate, to which the pickups should be pre-fixed.  Don't imagine anyone being interested in this above about £40, and as the principle source of bodies will be kits or s/h donors, don't expect high turnover, but it might be a goer if someone like Hattons or Rails, maybe Kernow, can be got on board.  Probably not going to be able to attach brake or other underframe detail for this price, and the market is probably not capable of doing it on their own.  

 

[tomparryharry]

16 hours ago, Steamport Southport said:

 

I was adding to Hayfield's post as he had quite a list of chassis and those were missing.

 

 

I don't quite understand the thread. Is it RTR chassis for old whitemetal body kits such as Finecast or GEM?

 

As they are already available RTR in most sizes. The relevant ones for the kits would be Jinty, 57XX, J50, 4F, B12, A3, L1/4-4-0 equivalent, etc. 

 

Although why you would want to put an A3 chassis under a Royal Scot like it says in the Wills instructions I was looking at earlier seems a bit strange in 2020.

 

 

 

 

Jason

 

Try  reading my first opening post.   Then, think about application. The use of the  word application in this instance is very, very broad. Is item X a specific application? Or, is item X a generic application? 

 

Then, think about production application. Think in terms of 3D printing, investment casting, scratchbuilding, kit-bashing. In fact, anywhere where the thought of application prevails.

 

In fact, it's my fault. I forgot to add the word imagination. For that matter also, visualisation. Using the words visualisation, imagination and application should cover most of it. 

 

Oh, and adaptability.... Yes,  adaptability.... It does seem some of our parishioners have cottoned on to what I'm talking about; enough to make entirely valid comments & observations. 

 

Happy modelling, Folks,

Ian. 

[Wheatley]

I read your opening post and I'm still not clear whether you are proposing a generic 0-6-0 chassis for a range of generic RTR 0-6-0s, or a generic chassis to go under the various kits available (including the increasing number of 3D printed ones, Hardy's Hobbies etc).

 

I think the ensuing discussion has established that:

 

a) Apart from Crewe and Derby there was no such thing as a generic pre-grouping 0-6-0

b) if you make it flexible enough to accommodate all the variations it will be too expensive for half the potential market

c) if you make it generic enough to keep costs down it will be too generic for the other half of the potential market

 

In any case, I'm out.

[The Johnster]

I think he meant a basic chassis form that could be produced to be capable of use beneath the bodies of a large number of later Victorian and early 20th Century 6 coupled inside cylinder locos, mostly 0-6-0s and 0-6-2s.  Like me, his interests are South Walian and this may 'inform' the concept.  I'd say there's  mileage in it; Swindon and Wolverhampton used the Derby spacing for standard gauge 6-coupled locos, right up to the 16xx.  Many pre-grouping South Wales 0-6-0 and 0-6-2 tanks come under this umbrella, and probably a good few locos from other parts of the country as well. 

 

The Crewe and Derby axle spacings were used widely on other railways and by outside builders, so can be regarded as basic generic standards for British 6-coupled inside cylinder locos for most railways but not all, and not for industrial locos.  Your gloomy assessment of the market is probably not too far off the mark, though; success would be predicated on how much detail and adaptability could be incorporated at what I reckon would be a £40 pricing, including motor, gears and pickups attached to motor feed wires by a keeper plate.  3 sizes of driving wheel have to be accommodated in something like a simple CKD kit, with no soldering and dovetail mounts for NEM couplings.

 

I might be interested in a Derby spacing for a 2721 and a proposed new chassis for a Wills 1854.  These are not hifi models to current standards, and a bit of compromise might be acceptable for them.  The 2721 is designed to fit the Triang Jinty generic chassis, which is based on the original R52 and incorrect for a Jinty.  I do not wish to upgrade it with a Bachmann pannier chassis, which would not align with the splashers, as my prototype, 2761, had fluted rods and that's a compromise too far for me, so it's running with it's original chassis, Hornby Jinty generic but at least with correct rods and matching the splashers.  The obvious answer would be to use a Bachmann Jinty/1F chassis, which would not align with the splashers (maybe I could cut them off and move them) but would preserve the fluted rods.  But these are not common on 'Bay and expensive to an extent that has stopped me from doing this; there is a limit to how much I want to lay out on a model that is never going to be better than it already is.  I've worked it up with new chimney, dome, safety valve cover, buffers, real coal, lamp irons, crew, cab window glazing, but the fundamental failing is the plastic skirts beneath the boiler, which cannot be really done much about.

 

The Wills 1854 is not really to much of a higher standard than this; a kind donation from Philou of this parish, it is beautifully put together but still has boiler skirts.  All this rambling is on the basis that I am typical of the market Ian is thinking about with this proposal.  I was back in the day capable of building a whitemetal kit chassis with separately purchased motors, gears, and wheels, but my eyesight and hand steadiness have deteriorated and I am no longer confident that I can do so.  Vague plans for Southeastern chassis kits for the 1854 and 2721, possibly one chassis with the bodies swapping it between them for operating sessions but I'm not yet sure that my proposed 1854 prototype, 1740, had fluted or fishbelly rods, are in the back of whatever is left of the mortal remains of my mind, but a TPH running chassis kit might be cheaper and just as effective.  

 

I'm in, at least until I see what it costs!