Mainly Diecast steam loco bodies

[34theletterbetweenB&D]

18 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. 

Alternatively it is the sum of small and measurable forces! For anyone wanting to run full length trains attention has to be paid to free-rolling of all the unpowered vehicles on the layout. The standard I still use is the one I was trained in at my first MRC: the model to roll away when placed on a  true 1 in 100 (1%). There's no difficulty in getting current RTR and kit built steel pinpoint in brass bearing stock  to perform to this standard - and typically to do much better.

 

As for the weight of the vehicles, as train weight approaches 5x the weight on the loco's driving wheels, neat effects result. Steam locos often do a half turn or two of wheel slip at dead slow - naturally - while starting a train. If the weight of locos is adjusted proportional to their power class, you then need adequate traction for the train load.  This may just be happy coincidence but so far Hornby have been bob on the weight I would aim at, for the 2F, 3P and 4P diecast bodied models I have purchased.

[CF MRC]

Admittedly I work in 2mm scale, but there is no doubt that the heavier a loco is, (with the weight in the correct places) the more it is likely to pull.  Modern Farish models are underwhelming in this regard because they are too light, a comment also made many times by Tony Wright when applied to commercial OO RTR locos, albeit with some exceptions. 
 

Tim

[MikeParkin65]

22 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. 

Plus then expect a Pacific to haul a 15 coach train around curves that would be too tight for a Jinty and a box van in real life.

[robmcg]

I look forward to finding out what R3819 diecast Duchess of Atholl will pull, as well as seeing photos of this apparently rare beast. 

 

I had a diecast MTH Big Boy a few years ago which wasn't short of adhesion.... 

 

 

But on the kind of roundy roundy BR layouts I have owned, type 3 radius, on a 9' x 4' table, anything over 5 carriages was fine,  and over 10 began to look odd.

[34theletterbetweenB&D]

On ‎14‎/‎08‎/‎2020 at 11:17, CF MRC said:

Admittedly I work in 2mm scale, but there is no doubt that the heavier a loco is, (with the weight in the correct places) the more it is likely to pull.  Modern Farish models are underwhelming in this regard because they are too light, a comment also made many times by Tony Wright when applied to commercial OO RTR locos, albeit with some exceptions...

Sufficient weight with the balance point as near as possible the centre of the coupled wheelbase is what we want. Not only good for traction, but also pick up. Make the loco a decent weight and there is no need for tender pick up (especially not by draggy wipers) in my experience. The driven wheels are far and away the most effective in maintaining good contact, focus there, save money by not needing to do anything else!

 

The Hornby locos with diecast bodies that I own are among the roughly one third of currently produced RTR OO steam loco models on my layout that came out of the box adequately weighted for traction to match their real tractive capability. It's the very 'spotty' adherence to this provision that is noticeable.

The honour roll:

Bachmann, 57xx, Jinty, Fairburn 4MT, C class, Midland 3F, J11, BR 9F

Heljan, O2

Hornby B12/3, D16/3, J15, J36, J50, K1, L1, BR 7MT

Oxford, N7

 

A diecast body isn't essential, especially on tank locos which may be well packed with ballast,  but it is a useful technique for a manufacturer to have available.

[maico]

According to 22C his model bellow comes in at 665g. Around

500g + in the body sounds ideal.

Edited August 15, 2020 by maico

[MikeParkin65]

2 hours ago, maico said:

According to 22C his model bellow comes in at 665g. Around

500g + in the body sounds ideal.

Metal gives a lovely lustre to the paint that plastic can’t. 

[robmcg]

4 hours ago, MikeParkin65 said:

Metal gives a lovely lustre to the paint that plastic can’t. 

 

Indeed and I am glad to have obtained one of these R3819s.   Yet to receive it here in NZ.

[robmcg]

8 hours ago, maico said:

According to 22C his model bellow comes in at 665g. Around

500g + in the body sounds ideal.

 

I wonder if 22C would mind if I took this image and tidied the background thus?

 

Will remove if offends. Nothing changed but background and sharpening. oh, and straightened the front bogie a tad.

 

 

 

What a lovely model!  

 

 

Edited August 16, 2020 by robmcg
correction

[tomparryharry]

On 12/08/2020 at 23:12, PenrithBeacon said:

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.

In any injection tooling, any error can be difficult to fix. With diecast products, it's normally a low-pressure process, and things like cast electrical components are a higher pressure. Once molten metal goes into its liquid state, quality control plays an absolutely vital part in the process. This isn't looking at the 2MT, and thinking 'nice', it's way back down the process chain. Things like chemical composition, porosity, temperature, humidity, etc. Mazak requires a slightly special alloy, and Zinc can and will 'burn out' if it's either too hot, or skimp in the original mix. I don't doubt that the foundry concerned uses a mass spectrometer, but I'd doubt they would use it on 'toys'. Copper is an asset material in its own right, so I'd doubt they would use it, if they can get away with it. Fair play to Hornby, they're making good models, but I very much doubt Hornby (or, any other manufacturer) will cut up a model for Spectral analysis. 

 

The error is very easy to fix, but not, repeat not, at the machine or casting processes. It starts at the goods incoming stage, with the raw material. Once you get on a deviated path, it's very difficult to get back on. Assets X Time = money squared, and it's a brave man who has the guts to call stop!

 

Cheers,

Ian.