OO gauge GWR Mogul and Prairie

[Miss Prism]

14 minutes ago, Les1952 said:

Alternately they've learned from a mistake.....

 

If that is so, they would have learned it some considerable time before the Mogul was released.

 

[Les1952]

4 minutes ago, Miss Prism said:

 

If that is so, they would have learned it some considerable time before the Mogul was released.

 

 

... in exactly the way that bigger companies often don't?

[David Stannard]

I'll certainly be putting my hand up for an 81xx in the future.

[tomparryharry]

When Dapol release the prairie, I hope there is opportunity to retro-fit the newer crossheads on the mogul. From what I'm seeing, the slidebar/crosshead relationship ( on the mogul ) is not quite right, leading to the flared sidebar  problem.  To their credit, Dapol appear to fully support the  mogul model, with a fair few spares. Perhaps it might prove prudent to prevail upon Dapol to increase their projected spares ( Prairie-manor ) list, to allow a mogul upgrade to take place. 

 

If nothing else, it proves that Dapol are savvy enough to listen to their customer base. If that is the case, I will politely request that Dapol make a low geared version  (about 50-1 )  or, make a low gear version as a spare item.   "You shall haul 60 wagons, my dear....."

 

Cheers,

Ian.   

[Chuffer Davies]

5 minutes ago, tomparryharry said:

 If that is the case, I will politely request that Dapol make a low geared version  (about 50-1 )  or, make a low gear version as a spare item.   "You shall haul 60 wagons, my dear....."

 

Cheers,

Ian.   

50-1 might take it too far the other way!  I’m moderately confident that Dapol have fitted a good motor to the Mogul and I would expect and have no concerns with them reusing it in the Prairie, but we have no way of knowing what it’s optimum RPM range is without carrying out independent tests which are certainly beyond most people to perform.  Ideally the gearing just needs to be optimised to the motor’s performance profile so that it has a realistic top speed for passenger working whilst at the same time providing good control at slow speeds for shunting etc.

 

it is inconceivable that Dapol would release the same model with customer options for gear ratios so let’s hope they are looking at improving the gearing for the release of the Prairie.

 

Frank

[tomparryharry]

Hello Frank. High Level sell a gear ratio at 54-1, so something within that range is perfectly feasible.  Your view about initial release makes perfect sense, but in fairness, Dapol are supporting the models, and, I suppose, the geartrain. It's not impossible that a spare idler gear with a more tractable ratio can be made available. 

 

I'd guess that the geartrain, from a production viewpoint, is already  decided. It's tried, & tested, and the commonality of parts across the models is understood by the contractors assembly staff, and more importantly, the QA inspectors...

 

Personally, I find anything is possible when making different versions of a model. The mogul is in 6 different liveries, then analogue, DCC, and sound...... Taking a pragmatic view, it pssibly won't happen at RTR level, but one can ask, can't they?

[The Johnster]

Gear ratios (much better on RTR models than they once were, but apparently the Dapol Mogul was a retrograde step) depend for their suitability on the type of layout the loco is to work on and the trains it is to pull. On my small BLT the quality of slow running and smoothness of starts and stops is paramount, so high gear ratios on locos with large diameter driving wheels (and 5’8” are the largest at Cwmdimbath) are A Good Thing.  But if I were running trains at line speed on a roundyroundy, then they would be less important, and on layouts where the train appears from the fiddle yard and runs through to the other end of the fy without stopping, much less important so long as the loco pulls the train smoothly at the requisite scale speed. 
 

My recommendations for steam outline  general use are 60:1 for shunting and mineral work (scale 25mph), 50:1 for general goods, 40:1 for everything else, perhaps 35 or 30:1 for express passenger.  In an ideal world, any capability a loco has for speed over and above line speed or it’s duty requirements is a waste of power that could be better geared for haulage and finesse of control; in the real world it’s a compomise.  
 

RTR does not deliver these idealised ratios (kits do!) except for express passenger locos, but modern motors and gears give adequate performances on DC layouts with restraint on the control knob (I always excersise restraint when I’m twisting my knob), well laid track, and clean railheads, wheels, and well adjusted clean pickups. 
 

I’d still like to see the above gear ratios adopted though, along with a standardised motor speed at set voltages.  Not gonna happen in The Johnster’s lifetime, though!

[melmerby]

2 hours ago, The Johnster said:

 

RTR does not deliver these idealised ratios (kits do!) except for express passenger locos, but modern motors and gears give adequate performances on DC layouts with restraint on the control knob (I always excersise restraint when I’m twisting my knob), well laid track, and clean railheads, wheels, and well adjusted clean pickups. 
 

I’d still like to see the above gear ratios adopted though, along with a standardised motor speed at set voltages.  Not gonna happen in The Johnster’s lifetime, though!

Not so

I have several RTR non express locos where the top speed is suitably restrained and need little if any reduction in max speed.

Try a Bachmann G2A or ROD.

[Oldddudders]

3 hours ago, melmerby said:

Not so

I have several RTR non express locos where the top speed is suitably restrained and need little if any reduction in max speed.

Try a Bachmann G2A or ROD.

Ditto. I have no difficulty in securing measured slow running with any of my RTR locos. As for all those quoted gear ratios - a propos which motor? An old-fashioned open frame, a cheap can, or something smarter with revs into 5 figures? All have a place in 4mm scale, and each can be tamed. And, yet again in this thread, the Dapol 43xx is being defamed for its slow-running properties. Fake news. Anyone who can't get theirs to run slowly and smoothly has a rogue unit or a very out-of-date control system. Mine ran slowly on DC, does even better on DCC without any decoder CV changes except to the loco number. 

[County of Yorkshire]

I have to say that I am astonished that Dapol are proceeding with this model. The Hornby version is still widely available and indeed was discounted fairly swiftly by many retailers. I just cannot see the market as being big enough for both versions? 

 

Surely bringing the Manor's development forward would be a safer bet and help to ward-off any pouncing on the prototype by other manufacturers? Clearly Dapol's business case for these is still seen as sound. 

 

I do think this will lead to bargain bins overflowing with prairies of both manufacturers. I hope I'm wrong but I can't see otherwise. It's happened before with LNER B1s, Adams Radial tanks, and BR 75xxx 4MTs. 

 

CoY

[melmerby]

1 hour ago, Oldddudders said:

Ditto. I have no difficulty in securing measured slow running with any of my RTR locos. As for all those quoted gear ratios - a propos which motor? An old-fashioned open frame, a cheap can, or something smarter with revs into 5 figures? All have a place in 4mm scale, and each can be tamed. And, yet again in this thread, the Dapol 43xx is being defamed for its slow-running properties. Fake news. Anyone who can't get theirs to run slowly and smoothly has a rogue unit or a very out-of-date control system. Mine ran slowly on DC, does even better on DCC without any decoder CV changes except to the loco number. 

I must have a rogue unit then as mine quite clearly appeared to be cogging at slow speed, which if the 18:1 ratio quoted is correct, is hardly surprising as the motor would be barely turning.

It's quite clearly overgeared as the unfettered top speed shows

It wasn't exhibiting the usual "tight" spot type of running common in new models

I tried it on pure DC and it also did it, but less obviously, with the Zimo decoder.

It has improved somewhat now that it has done a fair bit of running.

 

Edited January 26, 2021 by melmerby

[tomparryharry]

37 minutes ago, County of Yorkshire said:

I have to say that I am astonished that Dapol are proceeding with this model. The Hornby version is still widely available and indeed was discounted fairly swiftly by many retailers. I just cannot see the market as being big enough for both versions? 

 

Surely bringing the Manor's development forward would be a safer bet and help to ward-off any pouncing on the prototype by other manufacturers? Clearly Dapol's business case for these is still seen as sound. 

 

I do think this will lead to bargain bins overflowing with prairies of both manufacturers. I hope I'm wrong but I can't see otherwise. It's happened before with LNER B1s, Adams Radial tanks, and BR 75xxx 4MTs. 

 

CoY

 

Dapol must have good business reasons for continuing with the Prairie project. There are certain variations of the big prairie  which  haven't been made in RTR, such as the 31xx, 41xx, 3150 and 81xx . Another possible plus might be all-wheel pickup, especially with the rear radial truck on a prairie. Then there is the squared-off front running plate, ala pre-Holcroft. 

 

Like others, I've seen discounted prairies, but these have been the pre-upgrade versions, with the nice little moulded shovel on the tank top. 

 

One final reason might be that Dapol were actually quite far advanced on their large prairie project when Hornby  bought in theirs, possibly at the gallop. Having bought the project up to 80% odd completion, then I can imagine the Dapol production meeting:- "Well, we've come this far, let's finish it." Hornby might in fact be in a sticky wicket, especially if they haven't amortised their development cost over the life of the tooling. 

 

I should point out here that I'm in no way connected to Dapol, either by way of trade, or association. But, I've been in plenty of production meetings where this sort of discussion has taken place.  I've publicly said (2 years ago? ) That I said I'll be having one of these, so bring it on.....

 

Cheers,

Ian.

[tomparryharry]

3 minutes ago, melmerby said:

I must have a rogue unit then as mine quite clearly appeared to be cogging at slow speed, which if the 18:1 ratio quoted is correct, is hardly surprising as the motor would be barely turning.

It's quite clearly overgeared as the unfettered top speed shows

It wasn't exhibiting the usual "tight" spot type of running common in new models

I tried it on pure DC and it also did it, but less obviously, with the Zimo decoder.

It has improved somewhat now that it has done a fair bit of running.

 

 

hello Keith. Is the 18-1 ratio (quoted elsewhere ) actually correct? Should that be correct, then I would repeat my suggestion that the gearing is turned down, either as RTR, or an after-market spare.

 

Cheers,

Ian.

[melmerby]

7 minutes ago, tomparryharry said:

 

Dapol must have good business reasons for continuing with the Prairie project. There are certain variations of the big prairie  which  haven't been made in RTR, such as the 31xx, 41xx, 3150 and 81xx . Another possible plus might be all-wheel pickup, especially with the rear radial truck on a prairie. Then there is the squared-off front running plate, ala pre-Holcroft. 

 

Cheers,

Ian.

Hornby are already doing the 41XX

As regards the early footplate, I wouldn't discount that from Hornby like they did with the rather underwhelming 42XX, 52XX & 72XX

2 minutes ago, tomparryharry said:

 

hello Keith. Is the 18-1 ratio (quoted elsewhere ) actually correct? Should that be correct, then I would repeat my suggestion that the gearing is turned down, either as RTR, or an after-market spare.

 

Cheers,

Ian.

It would, I think, need the chassis to be reworked if it's the usual 2 stage set-up.

It's a mixed traffic loco so IMHO around 40:1 would be abetter choice.

It would cut the top speed to about 70mph or so, much more reasonable.

[57xx]

12 hours ago, Miss Prism said:

I'm surprised but pleased to see the new slidebars, if indeed these are to be representative of production, but in a way it makes what appeared on the Mogul less excusable.

 

Didn't the pre-prod samples of the Mogul have slidebars that looked fine? It was only when the production run landed that the wonky versions were seen.

[Miss Prism]

Powerful yes, good acceleration yes, but I doubt the large prairies got above 65mph.

 

[County of Yorkshire]

7 minutes ago, tomparryharry said:

Like others, I've seen discounted prairies, but these have been the pre-upgrade versions, with the nice little moulded shovel on the tank top. 

 

No, the new tool Hornby model was down to £99.50 with the likes of Rails within a few months of release. Others like Bure Valley Models still have them for £105. I paid £115 for mine when new. 

 

I'm not complaining at the prospect of bargains - far from it. Also, the 31xx and 81xx variants are to be welcomed, as is the Dapol take on GWR green which is infinitely superior to the Hornby sludge variant!

 

All I am saying is that I am astonished that the Dapol business case for these still stacks up. 

 

Full marks for their endeavour.

 

CoY

 

 

[57xx]

On 24/11/2019 at 19:35, The Fatadder said:

A couple of photos 


 

 

 

Straight slidebars as per previous post.

[tomparryharry]

6 minutes ago, County of Yorkshire said:

 

No, the new tool Hornby model was down to £99.50 with the likes of Rails within a few months of release. Others like Bure Valley Models still have them for £105. I paid £115 for mine when new. 

 

I'm not complaining at the prospect of bargains - far from it. Also, the 31xx and 81xx variants are to be welcomed, as is the Dapol take on GWR green which is infinitely superior to the Hornby sludge variant!

 

All I am saying is that I am astonished that the Dapol business case for these still stacks up. 

 

Full marks for their endeavour.

 

CoY

 

 

I've just had a quick look at Rails for prairie without success. so if they have discounted the Hornby version, perhaps they wanted the stock gone before they have a room full of both Hornby & Dapol models. 

[CoombeTown]

1 minute ago, tomparryharry said:

I've just had a quick look at Rails for prairie without success. so if they have discounted the Hornby version, perhaps they wanted the stock gone before they have a room full of both Hornby & Dapol models. 

They were available for approximately a day at that price, they sold out very fast.

If memory serves correctly it was just after the decision to no longer stock Hornby products when they had a clear out

[Harlequin]

The document that started off this flurry of speculation is dated 09/2020. It’s not new info and it predates the Mogul release.

 

So I don’t think it really tells us anything new about the Dapol Prairie, whether Dapol are going ahead as planned or any possible changes to the model.

 

Edited January 26, 2021 by Harlequin

[Chuffer Davies]

1 hour ago, tomparryharry said:

 

hello Keith. Is the 18-1 ratio (quoted elsewhere ) actually correct? 

 

Cheers,

Ian.

Yep...  1: remove chassis from body,  2: draw horizontal line on fly wheel, 3: turn motor by hand until crank pin at top dead centre. 4: continue to turn motor by hand until the crank pin is again at TDC counting the motor revolutions using the previously drawn reference line.  Answer 18......

 

Since I’m replacing the chassis as part of my EM conversion I have no axe to grind with regards the running characteristics of the Dapol chassis, but would suggest that I have not seen this  kind of ratio in a steam outline model since Hornby Dublo stopped using their original vertical motors in the 1960s.
Frank

[melmerby]

1 hour ago, Miss Prism said:

Powerful yes, good acceleration yes, but I doubt the large prairies got above 65mph.

 

Inclined to waddle a bit with full tanks, if I've heard correctly.

 

27 minutes ago, Chuffer Davies said:

 

Since I’m replacing the chassis as part of my EM conversion I have no axe to grind with regards the running characteristics of the Dapol chassis, but would suggest that I have not seen this  kind of ratio in a steam outline model since Hornby Dublo stopped using their original vertical motors in the 1960s.
Frank

Triang used to use a 2 start worm with a 40 tooth gear = 20 : 1, later versions (e.g. Hornby) have a single start worm and 40 tooth gear in the same basic chassis. The diameters of the gears are the same but the gear tooth angle is different.

I swapped a couple of XO4 2 starts for single starts, you can just about get away with it due to the slack tolerances.

[1466]

Wouldn’t it be great if , say Ultrascale , did a replacement gear set to lower the ratio to around 35 to 1 ? 

[The Johnster]

8 hours ago, melmerby said:

Not so

I have several RTR non express locos where the top speed is suitably restrained and need little if any reduction in max speed.

Try a Bachmann G2A or ROD.

 

I was making the point that gear ratios that are suitable for layouts where locos can reach realistic top speeds are not neccessarily those most suited to operation on small BLTs.

 

5 hours ago, Oldddudders said:

As for all those quoted gear ratios - a propos which motor?

 

I suggested that an ideal situation would be where motors ran at a standard rpm at set voltages, meaning that predictable results could be achieved and identical results on locos with the same gear ratios and driving wheel diameter.  This is an idealised aspiration situation, not reality.

 

3 hours ago, melmerby said:

It's quite clearly overgeared as the unfettered top speed shows

 

Yes.

 

3 hours ago, tomparryharry said:

There are certain variations of the big prairie  which  haven't been made in RTR, such as the 31xx, 41xx, 3150 and 81xx

 

The 61xx and 5101, of which the 41xx series is merely the later builds, are identical visually and in production by Hornby, Dapol pending.  By 31xx I'm guessing you mean the original Churchward large prairies with no.2 boilers, not the 1938 Collett locos (which I would buy if one were available RTR or even kit).  This had a no.4 boiler and 5'3" driving wheels, so I rather doubt that any RTR provider is champing at the bit  to make one...  The 3150 is more likely, as the chassis from the 61xx/5101 can be used, but it needs a new body tooling.  Being pedantic (moi???), Graham Farish made a 4mm 00 gauge RTR 81xx back in the 50s and 60s, not a bad model for it's day but well outclassed now!

 

3 hours ago, Miss Prism said:

Powerful yes, good acceleration yes, but I doubt the large prairies got above 65mph

 

There are tales of 14xx hitting 70+mph on the Chalford autos, and these only had 5'2" diameter driving wheels.  There seems no reason a Churchward 31xx, 3150, Collett 5101, or 61xx could not run as fast as a 43xx, Grange, or Manor.  I'd suggest scale 75mph as a reasonable top speed for a model of a large prairie, maybe a bit less for the 81xx and the Collett 31xx.  The latter class was noted for very strong acceleration, incidentally.