Kernow Adams O2

[NHY 581]

Hi all      Kernow have had my cash for a long time now, originally for the 7mm Well tank but transferred, hopefully, for a Maunsell liveried O2 in 4mm .  I have only just seen the prepro pictures and the first thing that hit me was that the cab cutout looked too low at the top. I find this has already been picked up and is certainly something which needs looking into.    It almost gives the impression that there has been some sort of mix up with the high roofed final series and the original series with low roofs even though all the planned models are the early batch. 

 

   It is not clear on the samples what smokebox rivet patterns will be produced as they don't seem to show any rivets at the moment.  I wonder if there is any hope of revisions being made as, from past experience, the model may well now be in it's finalised form. Delivery has clearly slipped somewhat but I certainly hope to have my model by the beginning of 2015.   Another problem which I think will rear its ugly head soon is the spectacle plate ventilator holes, these appear too large and too low and as they are always above the lining they may either finish up below the lining if it is to scale which will look very odd or the lining will be much lower than it should be which will look equally odd.   The latter may be what will be done and may also be why the cab cutout is too low to match the lining. Personally I would have preferred scale size holes in the correct position, even if they were only pin pricks, part way through to prevent moulding problems.  The clarity of the pictures makes it difficult to assess some other points raised in the forum and enlarging the views has not made much difference.  It looks as though this will be the first runner from the DJ stables so the standard set for this will be what future models will be judged by,.       Regards all  adrianbs

I am struggling with this one. The attached photos seem to speak for themselves regarding the spectacle vent holes.

The black and white view is a classic shot of O2 177 taken at Easton station in 1929 by H C Casserly. The colour shot is taken in the early 70s by an unknown photographer who I am unable to credit. If the vents are too low then it is by a gnats todgers width ( Victorian measurement based on research carried out in Shimla Summer 1898).As for the size of the holes themselves, then again a certain amount of leeway should be allowed, surely. Had these been modelled in 'half relief' then there would have been froth on the moon.

As for the rivets on the smoke box, well yes, the pattern is not readily visible but as the Stationmaster says, they are there. It is difficult to see due to the colour of the moulding but they are there. The first painted examples will show this better, I am sure.

I cannot comment on the cab cut out as I am not that familiar with the prototype.

 

However, whilst I would not slavishly buy a grossly inaccurate rtr model (though god knows we put up with a lot in the 70s and 80s !!) I have no problem with handing over my Queens pounds for one of these.

 

Let's not lose sight of the fact that this model will set new standards for Rtr models in terms of detail alone.

 

Personally I am happy with this model and we should not forget that all we have seen thus far are EP examples.

 

Even if these are faults, will I pre judge the rest of DJM releases based on this.....

 

Er. ..nope. I would like to think that I am a bit more objective than that.

 

Rob.

[adrianbs]

Hi  G-BOAF   All locos with cab front lining have the lining just touching the bottom of the vent holes or marginally below.  BR Black lined locos have no spectacle lining but BR Malachite, Southern Malachite, SR Maunsell and Adams or Drummond lined locos all do have lined cab fronts. The intention is to do one of of these liveries in the first run and presumably additional runs will cover other lined livery variants.  I am not sure if the vents holes have been lowered to clear the inevitable overscale roof thickness but if so I would rather they were blind and in the correct position than otherwise, especially as, being blind, they will cause far less mould release problems assuming the draught angle is from the outside face and they can also be made smaller.. Like you, I would far rather a further wait for any corrections but the way production slots in China dictate things unfortunately this and the finances decide if there is time available to alter a model.  Hopefully the attitude at Kernow is rather different to another company and accuracy may prevail over expediency. They may also be more open to take on board comments, as I found, when I first contacted them about doing a Maunsell livery loco to go with the Gate stock after the O2 was originally announced.  It seems many others were of the same mind and the new version was added to the first batch rather than letting Hornby sell lots of M7s to go with the coaches and thus miss out on significant possible sales ( That was the way I pushed it !! )

 

    I'm glad that there will be rivets on the smokebox although that, of course, opens another can of worms !!       Regards all   adrianbs

[Bluebell Model Railway]

I was fortunate last night to have a look at the Eps delivered in September so guessing they were EP 2.
Having worked on and with the only survivor of the class, I am certainly happy having had a look at the prototypes

I can confirm there are rivet detail on the front face of the smoke-box and around the top front edge.
As for the vent holes I assume your speaking in the front above the windows... I have never seen lining on the front of the cab, so not sure what lining is being spoken of.
Either way I will be down there next week.
Cab cut out also looks fine to my eyes, and I imagine were checked against the drawings for the locomotives, although I can go an measure it if you really want
Either way I have 2 on order and I am looking forward to the next samples.
 

https://www.flickr.com/photos/bluebellmodelrailway/15419438992/

Edited October 2, 2014 by Bluebell Model Railway

[adrianbs]

Hi nhy 581    I agree they may only be a tad too low and a tad to large in diameter but I do not have the advantage of being able to measure a prepro model.  I suspect the real holes are less than  0.5"  ie  less than 0.2mm on a 4mm model.  You may be able to confirm the size and this combined with a small lowering may well mean the lower edge of the hole may be significantly lower than scale which in terms of the proportions may well change the appearance when lining is applied. The lining will, I am sure, not be dead to scale and thus may well finish up either going right through the holes or having to be lowered further still.  The bottom edge of the holes should be less than 1mm below the roof lower edge. The problem is, a gnats todger, when scaled up by 76, becomes quite large. If the lining goes through the vents it will look odd with a series of holes in it which does not occur on the full size.  I would be willing to bet that the painting instructions specified that the lining was NOT to be interrupted by the holes. Even if the holes are in the correct position, the lining may have to be lowered to avoid them unless it is accurate scale width. I have come across similar problems with models which require lining and look very odd simply because the lining is not dead scale but the spaces available are.  For scaling purposes the lining on Maunsell (and probably Bulleid ) locos was 0.25" wide  ie  less than 1/10 of a millimetre in 4mm,  that is about the width of a hair !!         Regards all  adrianbs..

Edited October 9, 2014 by adrianbs

[G-BOAF]

Re Cab cutout, this was a splice I did a while ago. No not perfect in terms of perspectives being 100% on, but it illustrates the potential problem:

 

 

(original loco photo not mine, but not reproduced in entirity, from flickr, can be removed if breaking any rules. Similarly the CADs are from those posted on this thread)

 

BluebellModelRailway - are you able to divulge the impending 'things to be put right'???

Edited October 2, 2014 by G-BOAF

[Bluebell Model Railway]

i wouldn't over lay a CAD/ photo image as you will never get a reliable comparison... with an image (good old optical illusion). You would be better off with a drawing as this method will give you inaccuracy.. and always will.
 

Edited October 2, 2014 by Bluebell Model Railway

[Godfrey Glyn]

Hope this is of help in the discussion; very sure that I will be delighted when the parcel containing mine arrive. Looking forward to building Ventnor West - as a child I lived above the old station yard.

Godfrey

[G-BOAF]

i wouldn't over lay a CAD/ photo image as you will never get a reliable comparison... with an image (good old optical illusion). You would be better off with a drawing as this method will give you inaccuracy.. and always will.

 

I would partly agree, however given nearly everything else is dead on, the scientist in me says the disparity in the cut out is likely not just image distortion.... Happy to be proven wrong if someone can get an original works drawing....

[Bluebell Model Railway]

You also have to take in to account the image it's overlayed with was taken at a lower position compared to that of a CAD, I still wouldn't rely on it, but I am sure someone can clear that up, or I'll go measure the actual one haha.

Edited October 2, 2014 by Bluebell Model Railway

[adrianbs]

Hi All  I agree with G-BOAF  and would dearly like Bluebell M R to supply a few of the dimensions mentioned above .   Do we even know if Calbourne has had a cab rebuild ??

 A number of preserved locos have had their cabs raised, notably the VOR engines and in any case some of those measurements would be useful for my 7mm Adams locos as I have never been able to get to see Calbourne to date.  The engineer in me doesn't think photographic distortion could give rise to such a noticeable difference and I picked up the problem even before reading the forum or checking my library.   Unfortunately there is no end elevation on the GA printed in the Bradley book but it gives a height between cab beadings of approx 8.9mm at the centre of the top to the horizontals either side of the door by scaling off the GA.  That would be just under 2' 3" so the figure might well be 2' 3" as railway engineers did not mess about with silly fractions of an inch except when needed.. 

     Incidentally not all the "vent" holes are holes as the second to outside has a nut over the hole in most pictures and is slightly off line as per the previous close-up !!  B.4s are the same so Bluebell M R better check that out as well and tell us what is fitted there and if it was always there or a later fitting.    I look forward to seeing some real dimensions of both the model and of Calbourne for comparison.

       Regards all  adrianbs    PS  If G-BOAF's nom de plume is what I think it is, then I helped design and make a few bits, along with many thousands of others !   A

[Bluebell Model Railway]

I will see what I can do, I do not think off the top of my head it's ever had a new cab top, its had various bunkers over the years
You would be surprised what distortion can do... or even if the image has been adjusted in some way as no-one owns the image here.so can;t really comment.
I'll see what I can do but will be a week or 2, as I have no internet access on the island, so I'm sure someone who is more involved with the project can clear up any doubts.

[NHY 581]

Hi nhy 581    I agree they may only be a tad too low and a tad to large in diameter but I do not have the advantage of being able to measure a prepro model.  I suspect the real holes are less than  0.5"  ie  less than 0.2mm on a 4mm model.  You may be able to confirm the size and this combined with a small lowering may well mean the lower edge of the hole may be significantly lower than scale which in terms of the proportions may well change the appearance when lining is applied. The lining will, I am sure, not be dead to scale and thus may well finish up either going right through the holes or having to be lowered further still.  The bottom edge of the holes should be less than 1mm below the roof lower edge. The problem is, a gnats todger, when scaled up by 76, becomes quite large. If the lining goes through the vents it will look odd with a series of holes in it which does not occur or the full size.  I would be willing to bet that the painting instructions specified that the lining was NOT to be interrupted by the holes. Even if the holes are in the correct position, the lining may have to be lowered to avoid them unless it is accurate scale width. I have come across similar problems with models which require lining and look very odd simply because the lining is not dead scale but the spaces available are.  For scaling purposes the lining on Maunsell (and probably Bulleid ) locos was 0.25" wide  ie  less than 1/10 of a millimetre in 4mm,  that is about the width of a hair !!         Regards all  adrianbs..

I note your somewhat comprehensive reply.

Speaking as a customer, I will still be buying one if not more.

There is a school of thought that some lining is best omitted rather than portrayed over scale......but that would raise adverse comment wouldn't it.

 

As a OO gauge model locomotive, we accept that the wheels are to run on track which is too narrow don't we. There is no criticism at that particular compromise.

 

This will be a very acceptable model of an attractive locomotive.

 

Rob.

[Andy Y]

I've had an official response from KMRC to address the issues discussed:

 

 

They confirm that they do fully understand the differences between various O2s and have not got confused with the final batch with the higher cab.  This variant is one of the few that they have chosen not to tool for and the combination of tools already available for the O2 model, like the Well Tank, allows for detail variations down to differing rivet patterns. Like their forthcoming GWR 1361 tank this allows them to produce models incorporating the specific details to match the actual running number to those details.

 

 

The issue of the cab was raised many many months ago and was checked, double checked and checked again and no changes were required.  The laser scan matched the drawings and the real thing.  KMRC see this as a benefit of sharing the CADs and samples and acting on feedback received, as they have done over the last few years.

 

 

 

As a Kernow Model Rail Centre model the responsibility for checking and approving everything lies with KMRC.  They have had much help from many experts, particularly parties with knowledge and expertise in the specific loco and its variations, as well as much feedback at shows. 

 

 

 

Given that production of the models has been approved and they are currently working on the liveries and hope to receive these samples very soon.

 

 

[IWCR]

I  can  confirm  that  the  preserved  O2  retains  the  original  cab,  this  has  not  been  altered  or  rebuilt  during  preservation.

Indeed  LSWR  paint  has  been  found  on  parts  of  the  exterior  during  work.

Kernow  also  have  a  General  Arrangement   drawing  copied  from  the  original  LSWR  drawing.

I  suspect  perceived  mismatches  with  the  model  are  due  to  the  roof  edge  thickness  which  likely  has  to  be  overscale  for  manufacuring   practicalities,  (The  vertical  lip  would  only  be  around  0.5mm  to  include  roof  thickness  and  angle  iron  edge).

On  a  painted  model  this  area  is  black,  both  roof  and  cab  side  above  any  lining,  this  will  reduce  the  visibility  of  any  slight  discrepancy.  

 

Pete

Edited October 3, 2014 by IWCR

[Bluebell Model Railway]

Thanks IWCR and Andy, I think that pretty much clears that one up, It looked fine to me, at least I don't have to go and measure the gap, I'll un pack my ruler.
I guess like with anything in manufacturing as IWCR says there's limitations and practicalities of manufacture, either way I was happy with what I saw on the EP they capture the look and character of the O2 very well.

[adrianbs]

Hi All   Well, I am afraid that I am still not convinced, I have done different scaling checks to G.BOAF using the available material on this forum and am still prepared to stick my neck out and agree with G.BOAF that I think the cab aperture is too low and the distance between the bottom of the roof and the bottom of the beading around the doorway is about 25% too great.  I have also checked the ratio between width and height of the aperture and this gives a similar result.
    With reference to the ventilator holes, the images of the prepro models also seem to show that the holes are higher up on the cab back than the front which does not seem to be the case on the full size locos and I am very worried that when the livery of the SR lined green loco is being printed the lining will finish up either much too low, touching the spectacle window frame or going through the holes on the front spectacle plate.  The alignment of cab front and cab side lining relative to the doorway may be the reason for the doorway height having been reduced but that may have arisen as a result of the vent holes being too low in the first place.  The "Nut" showing on the second vent hole from the outside may well be some later addition as early photos appear to have a hole. The holes themselves seem to be the main problem as they appear to be far larger than scale, probably so that the pins are strong enough to withstand the moulding process and have a draught angle large enough to reach right through the cab front.  I am not sure if the pins go through the front from the inside or the outside but if they go from the inside and the roof is integral with the front there may be no way of changing size or position.
    As it appears the tools are now finalised I assume there is no possibity of alteration so if these points are incorrect they will remain so.  I have had 45 years designing and manufacturing models and using scaling from photos whenever there was no other option and I have never found serious errors have occurred when, in later year, more accurate information has been discovered.  Indeed on one occasion only a gnats private parts were the error in spite of numerous "Official" GA drawings showing completely different dimensions and shapes. This was something of a relief as I had made patterns in OO, O and Gauge 3 from my calculations.            Regards all   adrianbs    PS Have just read Petes post so measurements of Calbourne will be accurate and I look forward to knowing what they are in due course.  I have also been using the official GA for comparative measurements   A

[Andy Y]

Adrian, I honestly hope you've not just moved onto fresh grazing grounds to keep criticising ad nauseum until everyone would rather stick needles in their eyeballs? There's already been several reports from readers concerned that may be the case so can we keep some balance to it all please?

[Adams442T]

Interestingly I blew up the colour image in an attempt to see the cab front lining more clearly, and, unless my eyes are seriously deceiving me, the holes do seem to be going through the lining.

 

I realise it's a 1970s photo of a loco repainted into Southern colours, but surely there's a more than fair chance that they followed existing traces of paint or references showing the original positioning?

 

From my some 35 years experience in lining restoration on cars, motorcycles and bicycles you don't choose to line over holes or protruding bits unless it is how the original presented.

[adrianbs]

Hi All   Well if everyone is satisfied with inaccurate models I see very little point in having a forum to discuss the progress of a model. I am sure the manufacturers would love everyone to  heap praises on their forthcoming model and keep quiet about any faults they may perceive need mentioning.  We have all seen where that leads.

     Whilst I agree with Adams442T's comments  on the photo above, one swallow does not make a summer, especially if it is stuffed and mounted in a glass case in the middle of winter !!   I have gone through various books and at the most there are only one or two holes which slightly impinge on the lining at any period from "as built" to early BR Malachite. I have a personal interest in getting it right as Kernow have £100 of my money and I expect, in this day and age, to get an excellent product with no obvious faults. Adam442T admits himself that lining would normally be arranged to avoid holes or rivets if at all possible and I doubt Calbourne is now an exact reproduction of the loco when originally in service in the chosen livery.     Bluebell M R will, I am sure, admit that  Normandy on the Bluebell Railway  is far from a correct restoration of the loco at any period either in its current black or  earlier green livery. Preserved locos are a minefield for the unwary and often catch out the wary as well.. 

      Until we see actual measurements of both real and model O2 we cannot be sure how large the errors are, but as we have now been told no further tooling work is being contemplated we are, once again, faced with a "fait accompli" where customer participation is limited to buying or not buying. If we choose buying, we may be faced with complex alterations and partial repaints to get a model which satisfies, especially if we have ordered a Maunsell lined green loco.

     If it is no longer politically correct to comment on the accuracy of forthcoming models I feel that will have to be made clear to all in the forum rules, in the meantime silencing critics might be considered unjust.           Regards all adrianbs

[Andy Y]

 but as we have now been told no further tooling work is being contemplated we are, once again, faced with a "fait accompli" where customer participation is limited to buying or not buying.

 

Your chance for input was some time back Adrian.

 

Please don't try and call me out on commenting on accuracy; it's perfectly permissible, it's just that you've become somewhat 'notorious' for repetition (whether right or not) which grates with a lot of readers and it's therefore their sanity and eyeballs I'm considering in asking that once you've made a point to refrain from the repetition.

 

You've made the point now move onwards from that please.

[2ManySpams]

There is definitely interest in the facts. Commenting is fine and welcomed. It's the endlessly banging on until ears bleed that looses people.

 

Like many I was initially pleased to learn about the detail differences in the SR Pillbox and thankful that the issues with the Dapol model had been identified. The continued repetition of points turned me right off and resulted in me ignoring the thread.

 

Dare I offer that it's not what you say but how you say it and the frequency that causes folk to complain.

[Oldddudders]

Dare I offer that it's not what you say but how you say it and the frequency that causes folk to complain.

The Duracell Bunny comes to mind.....

[adrianbs]

Hi all    OK. So I will wait till later when the models are issued to comment on other faults that appear on prepros.      Bye bye   adrianbs

[2ManySpams]

Hi all    OK. So I will wait till later when the models are issued to comment on other faults that appear on prepros.      Bye bye   adrianbs

Is there not a middle ground between doggedly banging the drum and taking your ball home in a sulk?

[The Stationmaster]

 

      Until we see actual measurements of both real and model O2 we cannot be sure how large the errors are, but as we have now been told no further tooling work is being contemplated we are, once again, faced with a "fait accompli" where customer participation is limited to buying or not buying. If we choose buying, we may be faced with complex alterations and partial repaints to get a model which satisfies, especially if we have ordered a Maunsell lined green loco.

    

Excuse me but I'm now getting a little confused as a while ago you were telling us it was incorrect and now you're saying 'until we see real actual measurements' - so which is it?  (especially so in view of the comments KMRC have made via Andy a little earlier today).   If we haven't got 'real actual measurements' how do we know it's wrong?  All we have seen so far in terms of comments relating to or postulating inaccuracy are reference to photos none of which as it happens provide a direct exactly similar broadside view based on a photo taken at a right angle to the prototype (and my photos of the models very obviously weren't taken at a right angle either).

 

Lots of folk - including me - have various words to say about the accuracy or otherwise of models in various threads here on RMweb  (and no doubt elsewhere on the 'net) but I think and hope that many of us try to temper our views with a bit of understanding of mass production achievability measured against what is being delivered for the price we are being asked to pay.  That said it is very easy for any of us to criticise total stupidity by manufacturers but we are hardly in that court here (as far as I'm concerned anyway).  So perhaps critique tempered with a moderate approach and a consideration of sources rather than taking a few rather uncomplimentary photos (as mine were in some respects, for reasons already explained) and - as you have now said - making judgements against 'actual measurements' in stead of visual supposition might well be more constructive?

 

Don't get me wrong - some CADs we have seen published on RMweb have deserved a right royal slating but I don't think we're in that territory here to be honest.