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Accurascale's First Steam Locomotive; GWR Collett 78xx Manor Class!


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50 minutes ago, Dunsignalling said:

Only until BR sorted out the mistakes made by the GWR.

 

John

Sammy Ell took the lead in the early 50's with new approach to blast pipe designs to improve steaming rates. He doubled the steaming rate on the Manors (and the ex LNER V2 class as well).

 

Much of the research was taking place in the late 30's but, as you would expect, WWII go in the way of any other progress. 

 

Now there is the opportunity for a special edition. Ex GWR manor with stovepipe chimney on test. Even better with a Dynamometer car to go behind!

 

https://www.gettyimages.co.uk/detail/news-photo/great-western-railway-4-6-0-manor-class-locomotive-no-7818-news-photo/138599333

 

Mike Wiltshire

Edited by Coach bogie
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9 hours ago, Miss Prism said:

 

 

Mark has shown what can be achieved, and that is in P4, where clearances are extremely tight.

 

From Jeff Smith's Comet Mogul:

 

comet-mogul-slidebars.jpg.cfcfa324b9351bffec56554012c144d7.jpg

 

Here's a quickie suggested 00 clearance sketch - I've made a couple of assumptions on your rod thickness and your crankpin nut thickness, but I don't think I'm too far out, and admittedly the front wheelset sideplay is tighter than most RTR manufacturers are hitherto competent with:

 

2-cyl-x-section.png.3ab78f2f1f762fe7ef92661f373b8f9a.png

 

The above clearance is for the generalised GWR 2-cylinder case. For the Manor, the situation is far more generous, because (unlike the Prairie or Mogul) the front crankpin envelope never encounters the rear of the crosshead, and so neither of the dodges of narrowing the slidebar width or moving the piston axis out are necessary.

 

Double-plus good!

 

 

 

Thanks for that @Miss Prism but I dont think any kit built P4 locomotive has to deal with side play from a pony truck through radius 2 curves, which has us constrained here. As you will see with most, if not all RTR models there is a compromise here (hence me asking about comparable RTR model, not kit). We are working to see if we can make them more substantial and should be able to achieve gains, but prototypical width will not be possible on mass produced models, at least in this case. However, we will try our best to improve it as much as we can.

 

Cheers,

 

Fran

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10 hours ago, 9402 Fredrick said:

How later are we talking?

 

Hi @9402 Fredrick,

 

Soon! Sorry, all I can say right now! 

 

 

1 hour ago, JaymzHatstand said:

One thing that struck me in the description of the drive train was the mention of a three pole motor, is there a reason why this was chosen over a five pole? Not being critical, just curious!

 

I really enjoyed the launch video, it was well made, and interesting, so well done for that too!

 

Looking forward to seeing (and hearing) developments as they occur, and who knows, I might be tempted yet!

 

Cheers

 

J

 

Hi @JaymzHatstand

 

Sure, the advantage of the 3 pole motor is lower current draw, a more linear performance when coupled to the flywheel for smooth power delivery, and packaging (not a lot of room in there!) It will be a quality, not cheap 3 pole motor too, so performance will be excellent. If it isn't, we will reject it and work on another solution. 

 

1 hour ago, Butler Henderson said:

Cookham is specifically noted as being as preserved but maybe the list of models could be also be appended to indicate of the others that the real loco is preserved whether the model is either "Not as preserved" or "Also as preserved'.

 

Good idea @Butler Henderson we will look into that. However, for now, please read into the others as "in service condition" rather than preserved. 

 

22 minutes ago, Harlequin said:

Here's a thought: RTR models and engineering drawing of locos always represent flat sheets of metal as perfectly flat, er that is to say, planar.

 

But in the real world they never are. Look at any of the photos above - the sides of the tenders have subtle bulges and ripples that show up most when the paintwork is shiny and angle of photo acute.

 

So how about reproducing that in the model? The scans will have picked it up, won't they?

 

 

Ah @Harlequin, if only it was that simple! Yes, the scan would pick it up, but it would be impossible to scale correctly as they are so subtle when scaled to 1:76.2 Such distortion is usually achieved (thinking canvas on our coil A as a similar example) by a toolmaker taking a hammer and chisel to the tooling believe it or not. The whole point of the laser scan is merely as a reference guide to the designer to aid them in correctly drawing accurate CAD and a reference for shape and measurements. It does not generate into CAD itself.

 

EDIT - Also see @Islesy's point below! 

 

Cheers!

 

Fran

Edited by Accurascale Fran
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4 minutes ago, Accurascale Fran said:

 

Thanks for that @Miss Prism but I dont think any kit built P4 locomotive has to deal with side play from a pony truck through radius 2 curves, which has us constrained here. As you will see with most, if not all RTR models there is a compromise here (hence me asking about comparable RTR model, not kit). We are working to see if we can make them more substantial and should be able to achieve gains, but prototypical width will not be possible on mass produced models, at least in this case. However, we will try our best to improve it as much as we can.

 

Cheers,

 

Fran

One option to limit the side movement on the bogie is to allow more side play on the leading driven axle so the loco takes up a chord between the bogie pivot and the rear axle around the curve rather than a chord between the leading and rear axles causing an exaggerated overhang at the front.


Agree though that some compromise is necessary to accommodate the wider market and with 00 there is the built in benefit of the narrow gauge giving wider clearances.

 

Personally the clearances with the cylinders and slide bars are not a huge problem but for conversion to P4 the clearance inside the splashers is the most difficult to resolve and that is tight on the etched kit already so making an injection moulded splasher thin enough could be difficult without a high rejection rate.

 

Mark

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24 minutes ago, Harlequin said:

So how about reproducing that in the model? The scans will have picked it up, won't they?

That would entail separate tooling for each individual tender, as each has its own unique 'bulges and ripples'. It also requires a high degree of manual work by the toolmaker...

 

Edit: Fran and I doubled up on this reply Harlequin, the perils of getting sidetracked half way through replying! Didn't mean to 'tag team' you with the reply :D

Edited by Islesy
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22 minutes ago, Accurascale Fran said:

 

Ah @Harlequin, if only it was that simple! Yes, the scan would pick it up, but it would be impossible to scale correctly as they are so subtle when scaled to 1:76.2 Such distortion is usually achieved (thinking canvas on our coil A as a similar example) by a toolmaker taking a hammer and chisel to the tooling believe it or not. The whole point of the laser scan is merely as a reference guide to the designer to aid them in correctly drawing accurate CAD and a reference for shape and measurements. It does not generate into CAD itself.

 

EDIT - Also see @Islesy's point below! 

 

 

18 minutes ago, Islesy said:

That would entail separate tooling for each individual tender, as each has its own unique 'bulges and ripples'. It also requires a high degree of manual work by the toolmaker...

 

Edit: Fran and I doubled up on this reply Harlequin, the perils of getting sidetracked half way through replying! Didn't mean to 'tag team' you with the reply :D

 

A representative set of ripples would be good enough. I'm sure they are all broadly similar because of the positions of the structure inside and most modellers wouldn't be able to tell one tender (for instance) from another by looking at the ripple "fingerprint".

 

I'm sure that a mesh derived from the point cloud could be stitched into the CAD model. And that would translate to the tooling if the tooling were created by CNC from the CAD model...

 

No?

 

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11 minutes ago, Harlequin said:

 

I'm sure that a mesh derived from the point cloud could be stitched into the CAD model. And that would translate to the tooling if the tooling were created by CNC from the CAD model...

 

No?

 

 

No, sorry. That's not how a scan works. It's not something you can stitch into CAD. They're two completely different things. The scan is merely a reference point, think of it like a works drawing that the CAD designer bases his design on. Tracing essentially. 

 

And as before, it wouldnt scale. It's something very, very subtle on the real thing, scaling it 76.2 times would have it unrecognisable. Cool idea though!

 

Cheers,

 

Fran

Edited by Accurascale Fran
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9 minutes ago, Harlequin said:

 

 

A representative set of ripples would be good enough. I'm sure they are all broadly similar because of the positions of the structure inside and most modellers wouldn't be able to tell one tender (for instance) from another by looking at the ripple "fingerprint".

 

I'm sure that a mesh derived from the point cloud could be stitched into the CAD model. And that would translate to the tooling if the tooling were created by CNC from the CAD model...

 

No?

 

It won't work like that Phil - Fran has explained how the scan is used as a reference point rather than a design point but it goes way beyond that when you get to individual engines.  Firstly you can only scan as a reference point things which exist and there are more than a few 'preserved' tenders around which have been re-bodied in preservation (I'm not specifically talking 'Manors' here but they are involved).  Secondly if you then refer back to prototype photos of engines in traffic as a reference for detail differences - admittedly few on Manors but not on their tenders - you are in a very different ball game from the world of scanning what exists currently.

 

And as already explained the tooling means that you are likely to have all or in this case two, tender bodies all looking the same and many are likely to be wrong once they are in a particular livery because the models represent them at different stages in their lives.   So while it sounds to be an excellent 'really super' detail it isn't quite as simple as that if you wish to produce your model in a variety of liveries.  And a variety of liveries will always be an economic necessity to capture the broadest market.

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There is also personal preference, as with weathering, rusting etc. One person's highly realistic set of ripples will be a disfiguring blemish in the model to others.

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1 hour ago, Accurascale Fran said:

Thanks for that @Miss Prism but I dont think any kit built P4 locomotive has to deal with side play from a pony truck through radius 2 curves, which has us constrained here. As you will see with most, if not all RTR models there is a compromise here (hence me asking about comparable RTR model, not kit).

 

No, no, no, no.

 

1  Take a look at the Hornby Prairie (and you now have someone working for Accurascale who can tell you all about it).

 

2  The challenge of a pony truck going round radius 2 curves and avoiding the inside front of a cylinder is different from the challenge of a bogie going round radius 2 curves and avoiding the inside rear and inside front of a cylinder. These are two quite distinct cases.

 

3  The issue of the lateral clearance between a front wheelset crankpin and a slidebar does have an influence on the ability of a bogie to go round radius 2 curves. But they are two different engineering considerations. Sideplay on any front axle needs to be constrained, to a degree, but sideplay on a middle axle can be as much as you darn-well pleasy (subject to splasher clearance of course). There's buckets of clearance between the front face of the front wheel and the rear of the crosshead. The bogie wheelbase can be increased by say 3mm, 1mm at the rear and 2mm at the front - no one will notice. That said, I accept sideplay strategy at the front end is crucial, so let's see your sideplay plan. It's the bogie to cylinder clearances which are the killer, not the wheel to crosshead clearances.

 

Each aspect needs to be assessed and worked on its own merits, and will require different degrees of compromise. Lumping them all together under the habitual umbrella excuse of 'it just can't be done in 00' is the same old cobblers punters have been fed with for decades.

 

I thought you wanted to raise the bar?
 

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4 minutes ago, Miss Prism said:

 

No, no, no, no.

 

1  Take a look at the Hornby Prairie (and you now have someone working for Accurascale who can tell you all about it).

 

2  The challenge of a pony truck going round radius 2 curves and avoiding the inside front of a cylinder is different from the challenge of a bogie going round radius 2 curves and avoiding the inside rear and inside front of a cylinder. These are two quite distinct cases.

 

3  The issue of the lateral clearance between a front wheelset crankpin and a slidebar does have an influence on the ability of a bogie to go round radius 2 curves. But they are two different engineering considerations. Sideplay on any front axle needs to be constrained, to a degree, but sideplay on a middle axle can be as much as you darn-well pleasy (subject to splasher clearance of course). There's buckets of clearance between the front face of the front wheel and the rear of the crosshead. The bogie wheelbase can be increased by say 3mm, 1mm at the rear and 2mm at the front - no one will notice. That said, I accept sideplay strategy at the front end is crucial, so let's see your sideplay plan. It's the bogie to cylinder clearances which are the killer, not the wheel to crosshead clearances.

 

Each aspect needs to be assessed and worked on its own merits, and will require different degrees of compromise. Lumping them all together under the habitual umbrella excuse of 'it just can't be done in 00' is the same old cobblers punters have been fed with for decades.

 

I thought you wanted to raise the bar?
 

 

Hi @Miss Prism,

 

As I stated in my response we are looking at all aspects in improving in this area, I merely explained the issue we are facing and that a P4 kit built loco is not going to get us where we need to be as they're built for a different purpose and tolerance. Once again, we are looking at ways of making improvements in this area, including using our collective experience within our team to make it as best as we possibly can, but there will always be mass produced compromises at play, no matter what. If we can do it better, we will, and we have a track record of changing things based on feedback and first toolings. 

 

Appreciate the feedback.

 

Thanks,

 

Fran

 

 

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There is meaningful and informed discussion @Miss Prism, and there is rudeness and arrogance. Can we err towards the former, and shy away from the latter please? You have raised an issue that we have looked at already, and will look at again to see if the appearance of the slide bar can be improved. 

This is EP1, we expect to have to make adjustments and there are more major areas that are worthy of attention.

Your comments have been noted, we are looking to take action, so can we move on from this now please? Drop me a line if you wish to discuss further, just like we've done in the past?

 

Best wishes,

Paul.

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1 hour ago, Harlequin said:

A representative set of ripples would be good enough. I'm sure they are all broadly similar because of the positions of the structure inside and most modellers wouldn't be able to tell one tender (for instance) from another by looking at the ripple "fingerprint".

May I opt for a model without ripples, please?

 

I'm of the view that this kind of thing, whilst prototypically accurate, falls into the same camp as rough, uneven trackwork in a yard. You would have to be extremely careful, not to say highly skilled, to reproduce such a thing in 4mm scale and not simply have something that looks like 'you can't lay track!'

 

Perhaps subtle weathering could go some way to reproduce the effect, if desired?

 

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We won't be reproducing ripples in tenders!

It does get discussed though - the scanning of the 71 when I was at Hornby led to a similar discussion. Now that really was warped!

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9 minutes ago, Islesy said:

We won't be reproducing ripples in tenders!

It does get discussed though - the scanning of the 71 when I was at Hornby led to a similar discussion. Now that really was warped!

That was only because someone else was promising real rivets, a fully operational cab and anything else people asked for.

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33 minutes ago, Captain Kernow said:

I'm of the view that this kind of thing, whilst prototypically accurate, falls into the same camp as rough, uneven trackwork in a yard

Or grain on timber. The depth of most surface changes due to shrinkage on weathered planks are probably about one thousandth of an inch at 4mm scale.

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Reactions in chronological order:

 

1] Surprised – I was not anticipating a steam loco from Accurasale

2] Appreciative – It’s a GWR loco (just!) :)

3] Disappointed – A duplication of something that I was intending to purchase from another manufacturer

4] Impressed – Particularly the DCC and sound provisions, an on-board stay-alive feature is something we should have seen from all manufacturers before now.

5] Anticipation – It looks like this is going to be available very much sooner than usual after a RTR announcement.

6] Confused – is monogram actually the “shirtbutton” motif? (A definition of monogram is two or more interwoven letters, that design had long gone before the Manos were built).

7] Mildly miffed – A probable choice of one for my chosen time period, but better than none.

8] Fairly committed – I’d like to see how my Dapol Mogul runs and sounds when it finally arrives so that I have a benchmark, but based on information to hand at the moment I’m 90% certain to order 7801 as a sound fitted model.

 

A very positive development from Accurasale (even if I wish it had been a “Saint” instead :P )

 

Best of luck with the enterprise.

 

Pete.

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9 minutes ago, Star-rider said:

Reactions in chronological order:

 

1] Surprised – I was not anticipating a steam loco from Accurasale

2] Appreciative – It’s a GWR loco (just!) :)

3] Disappointed – A duplication of something that I was intending to purchase from another manufacturer

4] Impressed – Particularly the DCC and sound provisions, an on-board stay-alive feature is something we should have seen from all manufacturers before now.

5] Anticipation – It looks like this is going to be available very much sooner than usual after a RTR announcement.

6] Confused – is monogram actually the “shirtbutton” motif? (A definition of monogram is two or more interwoven letters, that design had long gone before the Manos were built).

7] Mildly miffed – A probable choice of one for my chosen time period, but better than none.

8] Fairly committed – I’d like to see how my Dapol Mogul runs and sounds when it finally arrives so that I have a benchmark, but based on information to hand at the moment I’m 90% certain to order 7801 as a sound fitted model.

 

A very positive development from Accurasale (even if I wish it had been a “Saint” instead :P )

 

Best of luck with the enterprise.

 

Pete.

Never forget - he who announces first is not necessarily he who had development and design work underway first, and it's not the first time that has happened.  Dapol announced showing photos of prototype locos, Accurascale has announced showing EP models and decoration drawings.

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Well it looks like I might be adding two Manors to my roster, I will have to wait and see what Dapol's EP's look like but for the moment I think I might dump theirs and go for the new kid on the blocks model as the EP looked pretty good in the video, can't wait to see what the painted samples look like.

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31 minutes ago, TheSignalEngineer said:

Or grain on timber. The depth of most surface changes due to shrinkage on weathered planks are probably about one thousandth of an inch at 4mm scale.

Absolutely, another element that's almost essential for 'some' rolling stock, yet so difficult to replicate.

Edited by Islesy
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Of course the elephant in the room is that an excellent late 1930s GWR locomotive needs some equally excellent mid-late 1930s GWR coaches to pull.....

Edited by Pteremy
correction
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This might be a stupid question but what does this mean? (pulled from AccuraScale's page)

  • Optional overhead warning plate bracket on late-BR examples

Is it that this is a feature fitting as standard to the late BR versions i.e. part of the tooling, or an after market option i.e. a piece in a bits bag with couplings etc.?

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