Using one chassis for several classes of locos

[Hobby11]

Something that came up when discussing the J50 and wondering if the chassis could be used for other classes of locos. Back in Triang days we saw the same chassis (especially the Jinty) used for several different classes with a new body. Since then, with the help(?) 0f magazine and online reviews comparing every single dimension down to the size of the whistle that has become a big no-no. "Everything must be to exact dimensions", etc., etc.. But I do wonder if we have maybe gone too far the other way and we should perhaps revisit the concept.

I am not proposing the return to the Triang days where that chassis was used in several locos despite it's unsuitability (Triang 3/4f tender loco for example?), but I am suggesting that if the chassis is within a mm or so then it could be used on other classes of loco. Most people would like to see more locos out asap and using a "common" chassis would enable to designers to just make the body thus reducing development time, amongst other things.

I can see the suggestion being met with derision by the finescale people, and fair enough, I'd expect that reaction from them, but for most of us is that mm that important, "If it looks right, it is right"?

[Silver Fox 17]

2 minutes ago, Hobby1707822967 said:

Something that came up when discussing the J50 and wondering if the chassis could be used for other classes of locos. Back in Triang days we saw the same chassis (especially the Jinty) used for several different classes with a new body. Since then, with the help(?) 0f magazine and online reviews comparing every single dimension down to the size of the whistle that has become a big no-no. "Everything must be to exact dimensions", etc., etc.. But I do wonder if we have maybe gone too far the other way and we should perhaps revisit the concept.

I am not proposing the return to the Triang days where that chassis was used in several locos despite it's unsuitability (Triang 3/4f tender loco for example?), but I am suggesting that if the chassis is within a mm or so then it could be used on other classes of loco. Most people would like to see more locos out asap and using a "common" chassis would enable to designers to just make the body thus reducing development time, amongst other things.

I can see the suggestion being met with derision by the finescale people, and fair enough, I'd expect that reaction from them, but for most of us is that mm that important, "If it looks right, it is right"?

Totally agree, as you know I have many, many other TT 120 locos using the A1 chassis but only two required the A1 sized wheels, and then, my Lord Nelson should really have the rear set further away.

For me, it is the general look and appearance of a model, not the exact half mm.

[LTSR_NSE]

I’d certainly appreciate Hornby releasing either whole chassis, or at least complete sets of components - to encourage modelling & individual creations.  They obviously would need to separate these from ‘warranty spares’ to prevent modellers compromising rtr repairs.

Regarding them using (even slightly more) common or generic chassis for their own models, whilst I’m sure some (including myself) would happily accept this, I fear it would put off others that are attracted by greater accuracy.  Thereby creating a finescale/railroad divide between models that possibly the TT:120 market isn’t yet developed enough to accommodate?

Perhaps the J50 is just an unfortunate example? (The uneven wheel spacing is quite pronounced - and likely still to be noticeable in 1:120 scale!)

Edited April 6 by LTSR_NSE

[GMD]

@LTSR_NSE - re the uneven wheel spacing - forgive my ignorance of the prototype and the engineering behind it - but do you know why was this done?

[Silver Fox 17]

42 minutes ago, LTSR_NSE said:

 

Regarding them using (even slightly more) common or generic chassis for their own models, whilst I’m sure some (including myself) would happily accept this, I fear it would put off others that are attracted by greater accuracy.  Thereby creating a finescale/railroad divide between models that possibly the TT:120 market isn’t yet developed enough to accommodate?

This again opens up the "you cannot please all the people all the time".

Some only want scale just like some only want GW stream.

Others are happy with whatever models are produced just as some are not bothered by 100% accuracy. I have a couple of tanks that should have 5'8" wheels but with only 6'8" available that is what is used.

[Silver Fox 17]

2 minutes ago, GMD said:

@LTSR_NSE - re the uneven wheel spacing - forgive my ignorance of the prototype and the engineering behind it - but do you know why was this done?

It seems to be a GNR thing as a few of their locos, or LNER afterwards, used that spacing. The N2 is identical for spacing but requires larger wheels, the same goes for the B17 and possibly the B1.

[Rallymatt]

I think that model ship has sailed! 
The hobby a series of compromises and it always will be but it’s quite niche and with people broadcasting to the world from a carpet or their garage you can hear the whelps of delight in their criticism of any manufacturer who dares to go down that track in any scale. No matter how well intentioned the industry will avoid that idea like the plague although as individuals we can whatever we like. 
Something I never expected to notice was how with TT:120 the correct scale/gauge does capture the balance in appearance of models and when you look again at OO or British N you start seeing the ‘narrow gauge’ effect. Once the fidelity bar has been raised it’s very hard to go backwards for a manufacturer. The constant drive for more accuracy ultimately leads to reduced options and increased costs to us, it’s really the consumer’s fault although few will accept it. 

[Going Spare]

@GMD - I do not know whether it is the case with the J50 but I believe the size of the firebox often determined the spacing between the centre and rear axles.

[GMD]

Thanks @Silver Fox 17 and @Going Spare. Both very helpful! 

@RallyMat I agree - the look of 00 never bothered me before - but now...

[StuLarge]

I had wondered about the possibility of generic modellers chassis to allow the scale to flow as did TT3 with the likes of GEM etc... (particularly after visiting Dad's train room) but I presume that's not for the likes of Hornby.

I did also wonder about a "railroad" range level of detail.

But I think one of the appeals of a true scale is the true (in so far as possible) detail.

 

Edited April 6 by StuLarge
Personal opinion added

[Too Tall]

I agree with RM, its fine for individuals who can apply rule 1 at their own level of acceptance, but a major manufacturer doing it these days isn't a good move.

@Silver Fox 17  There are some 14mm (maybe 5'6) at OO/HO Locomotive Driving Wheels, axles, crankpins (scalelink.co.uk)

[Hobby11]

I was only talking about very small differences, say a mm or so. How many of you could actually tell if a wheelbase was that far out without a ruler?

Edited April 6 by Hobby1707822967

[D9020 Nimbus]

Well, there are locos — even recent ones — where not all the measurements are accurate. The Bachmann OO Ivatt Atlantic has undersized wheels; if you see how close the wheels are on the real thing you will understand why. It doesn't seem to have generated much adverse comment.

[Silver Fox 17]

3 hours ago, Too Tall said:

 

@Silver Fox 17  There are some 14mm (maybe 5'6) at OO/HO Locomotive Driving Wheels, axles, crankpins (scalelink.co.uk)

There are a few different wheels I could get BUT not to fit the non standard Hornby axle and then I am not going to even try to swap the gear wheel over. Have you tried?

I have used Scalelink a few times and are on my TT 120 J39 and 8F.

[Silver Fox 17]

3 hours ago, StuLarge said:

I had wondered about the possibility of generic modellers chassis to allow the scale to flow as did TT3 with the likes of GEM etc... (particularly after visiting Dad's train room) but I presume that's not for the likes of Hornby.

 

 

Is your dad Eric by any chance?

[StuLarge]

23 minutes ago, Silver Fox 17 said:

Is your dad Eric by any chance?

He absolutely is 👍🏼

[Moccasin]

8 minutes ago, StuLarge said:

He absolutely is 👍🏼

Not Eddie….

[Too Tall]

2 hours ago, Silver Fox 17 said:

There are a few different wheels I could get BUT not to fit the non standard Hornby axle and then I am not going to even try to swap the gear wheel over. Have you tried?

No, I didn't realize you were utilizing the Hornby axle and chassis.🙂

[Silver Fox 17]

8 minutes ago, Too Tall said:

No, I didn't realize you were utilizing the Hornby axle and chassis.🙂

The Hornby chassis's are so nice that apart from the Castle nearly everything else utilises the Hornby A1 chassis unless I use a Halling bogie in a tender. 

I still have two tank locos with my own chassis's but they will have to do until Hornby fetch out a suitable donor. The J50 will do one, the other I will have to wait a while.

Edited April 6 by Silver Fox 17

[Hobby11]

16 hours ago, D9020 Nimbus said:

Well, there are locos — even recent ones — where not all the measurements are accurate. The Bachmann OO Ivatt Atlantic has undersized wheels; if you see how close the wheels are on the real thing you will understand why. It doesn't seem to have generated much adverse comment.

Quite, it's common where the loco has splashers and the wheels have to fit under them but with the outsized flanges the wheel diameter is reduced.

[D9020 Nimbus]

On the real Ivatt Atlantic the gap between the driving wheels is tiny — you can't get a finger between them, and the flanges are proportionately larger on models.

[Silver Fox 17]

It is a good job the rivet counters don't look at mine then with at least 10 different classes of loco all using the A1 chassis.

If I waited for Hornby to do all these "to scale" I think it would be well over 10 years or more, an then they might do some of these.

Edited April 8 by Silver Fox 17