Pennine MC Posted June 4, 2011 Share Posted June 4, 2011 Currently the Western is complete in a single CAD form but the following issues have been identified to be addressed. 1) The manufacturer has altered the grilles so they are on the centre line and not offset I'm not sure I understand this. Are we talking about the fan grilles on the roof? 1 Link to post Share on other sites More sharing options...
Andy Y Posted June 4, 2011 Author Share Posted June 4, 2011 Are we talking about the fan grilles on the roof? That's correct, this shot of robertcwp's that's appeared here shows the offset - http://www.flickr.com/photos/robertcwp/2189197301/ Link to post Share on other sites More sharing options...
Pennine MC Posted June 4, 2011 Share Posted June 4, 2011 Yep, I'm still confused: . We also managed to capture the off set fan grillsnicely too. Dave says they're offset, and I know they're offset, so why have they since been moved to the centre line? Link to post Share on other sites More sharing options...
Andy Y Posted June 4, 2011 Author Share Posted June 4, 2011 From the dialogue I've had it seemed to have been the factory who moved them (from the CAD elements provided) on the assumption that they were incorrect. The error is being corrected. Link to post Share on other sites More sharing options...
Raffles Posted June 4, 2011 Share Posted June 4, 2011 Might it be fair to suggest that the round part of the grilles were always offset but the factory moved the walkway section so it ran through the centre of the round grilles? It would seem reasonable to surmise that the walkways have now returned to the centre line. Does that make sense? I'm not sure... Link to post Share on other sites More sharing options...
Etched Pixels Posted June 4, 2011 Share Posted June 4, 2011 As built all were fixed, but alterating the RH one to hinged started circa 1964. It would be nice to have the early variation as an option so you can run an early 'Thousand' (introduced from December 1961) with a very late King (which were all withdrawn by the end of 1962). Indeed - but the higher level grilles are still a slat short even for those locos as far as I can see from the early photos ? I'm also wondering if there should be more of a downward curve to the bottom of the valence below the buffers. Can't quite decide and I'm always wary of trying to judge shape accurately from CAD images. Link to post Share on other sites More sharing options...
robertcwp Posted June 4, 2011 Share Posted June 4, 2011 I wondered why one of my Western photo collection suddenly had 65 hits in one day. The only one of the major hydraulic classes where the roof fan grilles were on the roof centre line were the D800 Warships. Hymeks had an offset grille, as did Westerns. One of Lima's many mistakes on their Western was to put the grilles on the centre line of the roof. On the Western, the walkways were on the roof centre line. This shot is a better illustration. 5 Link to post Share on other sites More sharing options...
MD655 Posted June 4, 2011 Share Posted June 4, 2011 That is correct. The roof fan apertures are offset but the walkway grid is on the centre line of the loco. The reason for this is that the cooler groups are off set to one side internally within the loco to allow room for a walkway down the one side giving access to the engine room. Link to post Share on other sites More sharing options...
Pennine MC Posted June 5, 2011 Share Posted June 5, 2011 That is correct. The roof fan apertures are offset but the walkway grid is on the centre line of the loco. Yeah, I think most of us having an interest in the type know that (or have grasped it). The point here is that this key idiosyncracy was scanned correctly, but then made incorrect at a later stage by a contractor, necessitating further correction. Not only that, but explaining here what has happened has caused further confusion, despite the good intentions of all involved. It's quite a good illustration, I think, of how the various chains in the model making process mean that (for any manufacturer) it isnt as simple as it might appear. It also occurs to me that it shows why laser scanning isnt the panacea it's made out to be, partly because of the wild card mentioned above and also because of the lack of sharpness in the cab corners that Bernard mentioned in post #43 Link to post Share on other sites More sharing options...
buffalo Posted June 5, 2011 Share Posted June 5, 2011 ...It also occurs to me that it shows why laser scanning isnt the panacea it's made out to be, partly because of the wild card mentioned above and also because of the lack of sharpness in the cab corners that Bernard mentioned in post #43 I doubt if anyone who actually knows anything about laser scanning makes it out to be a panacea, it's more a matter of those who don't imagining it to be. You've identified one fundamental issue, that of identifying edges. The scanner just produces a cloud of points and inserting the edges in the right place and with the right radius/sharpness is part of the skill in converting these to a CAD model. Nick 2 Link to post Share on other sites More sharing options...
Pennine MC Posted June 5, 2011 Share Posted June 5, 2011 I doubt if anyone who actually knows anything about laser scanning makes it out to be a panacea, it's more a matter of those who don't imagining it to be. Agreed Nick - but modellers at large clearly do imagine it to be so (and a cynical man might say there's an element of spin that can be used there ) You've identified one fundamental issue, that of identifying edges. The scanner just produces a cloud of points and inserting the edges in the right place and with the right radius/sharpness is part of the skill in converting these to a CAD model. Again agreed, I do understand that. It's essentially just another way of measuring which has the potential to be more correct, but isnt automatically so: The scanning was the most complex we have ever done, as mindful of other attempts in all gauges to replicate this model unsuccessfully, i asked for not the usual 4 points of scanning but 10 points. This was because i wanted to make sure that pesky roof , cab roof front (peak) and 'nose' with cab front windows and distances etc were scanned very accurately. So despite this more rigorous specification, the cab corners still slipped through the net. I'm not sniping BTW, just again pointing out the potential for error - it's a useful illustration of the pratfalls that can affect any manufacturer. Link to post Share on other sites More sharing options...
BernardTPM Posted June 5, 2011 Share Posted June 5, 2011 The other point with laser scanning a near 50 year old loco is that it will pick up on all the surface lumps and bumps acquired over the years (as well as the fact that the surfaces were probably never as clean and accurate as the designer might have intended). Link to post Share on other sites More sharing options...
buffalo Posted June 5, 2011 Share Posted June 5, 2011 The other point with laser scanning a near 50 year old loco is that it will pick up on all the surface lumps and bumps acquired over the years... One might argue that that is the intention... On the other hand, it all depends on the size of those lumps and the scanned point density. The process of transferring the point cloud to a CAD model is essentially one of fitting surfaces to the points in the cloud. This is where operator intervention is required to determine whether the one or two points that do not fit the surface represent a rivet or bolt head, a lump or dent, or just a scanning error. In addition to the 3D point cloud, most scanners generate matching 2D images (i.e. digital photos) from each scanning location and these are invaluable in resolving such issues. Nick ps. of course, if the scanned point density is too low, it is equally possible to miss some rivets, bolt heads, etc. Laser scanning is not necessarily the rivet-counter's panacea Link to post Share on other sites More sharing options...
craigwelsh Posted June 5, 2011 Share Posted June 5, 2011 One of Lima's many mistakes on their Western was to put the grilles on the centre line of the roof. On the Western, the walkways were on the roof centre line. Indeed which was why i'd made the joke earlier about sending the CAD to the same bloke Lima took their drawings. He was obviously adamant they should be on the centre.. The resolution of the scan should have picked up the cab shape very well, i'd assume it was during the conversion stage that resolution has been lost. Link to post Share on other sites More sharing options...
RMweb Premium brushman47544 Posted June 6, 2011 RMweb Premium Share Posted June 6, 2011 Grilles are indeed a bit odd as noted - the 3 left and right most on the roof angle are a slat short. as well as the one body side grille being different on the real beastie. From the dialogue I've had it seemed to have been the factory who moved them (from the CAD elements provided) on the assumption that they were incorrect. The error is being corrected. So despite this more rigorous specification, the cab corners still slipped through the net. To me the latest CAD looks very promising. Just looking at the drawings rather than studying them in detail, these three items above appear to me to be the most noticeable to the eye. The most obvious being the right hand bodyside grill, for which there should be different (opening) variant as Etched Pixels and Bernard TPM say. But is there any more news on the locos (or body variants) to be produced in the first run, in view of the issues with those originally selected, such as the real D1029 not having headboard clips? Link to post Share on other sites More sharing options...
Geoff Endacott Posted June 6, 2011 Share Posted June 6, 2011 But is there any more news on the locos (or body variants) to be produced in the first run, in view of the issues with those originally selected, such as the real D1029 not having headboard clips? ...and the real D1028, the real D1027, the real D1026 and the real D1025. Geoff Endacott Link to post Share on other sites More sharing options...
DapolDave Posted August 16, 2011 Share Posted August 16, 2011 Hi everyone, Just back from a break and have received the latest Class 52 'Western' images. They are posted here for thoughts as always. However i do have a request. Anyone that knows me knows i'm not the easiest person to get onto locomotive roofs And it appears our scanning is in need of a top up regarding the roof panels and lift eyes / walkway. if anyone has any details on this regarding panel widths and close ups of the aformentioned walkways and eyes, then i'd be happy to hear from them, or else it's carting myself off to Tyseley with a big ladder / cherry picker (delete as appropriate ) Anyway, here are the latest images and i'm still not 100% happy with the cab front radiuses, and welcome feedback. Note that this cad/cam does have the pipes under the fuel tank added and a very big cavity for a speaker plus enclosure (the largest rectangular one DCC supplies have) for those that wish to convert to sound. cheers Dave 9 Link to post Share on other sites More sharing options...
RMweb Gold Happy Hippo Posted August 16, 2011 RMweb Gold Share Posted August 16, 2011 Dave, Thank you for the latest update on progress with the Western. The time and effort that you have put into this project: plus keeping RMWeb informed and taking on board the forum members various comments regarding shape and positioning etc, shows how much you want this loco to be as true to prototype as is possible in this scale. Although it doesn't really fit into my layout plans, I do have a soft spot for this class of loco and it is one that I must have. There is no doubt in my mind that it is going to put all the other manufacturers interpretations of this loco into the shade. Regards Richard Link to post Share on other sites More sharing options...
RMweb Premium TheDukeOfWellingtons Posted August 16, 2011 RMweb Premium Share Posted August 16, 2011 Hi Dave. A couple of things stand out for me:- The lower edge of the roof panel above the cab should be horizontal, parallel with the other roof panel edges. All of the slope down to the cab's 'peak' occurs forward of this panel. The horn enclosure looks a little 'flat' at the front making me question the downward slope of the cab roof, maybe not quite steep enough? The curvature on the horn enclosure is also a little too generous as per the front corners of the loco. A much sharper radius can be observed on the real thing. Best of luck in your quest to produce the definitive Western. I've got layout plans which will require several ............... Dave. Link to post Share on other sites More sharing options...
Andy Y Posted August 16, 2011 Author Share Posted August 16, 2011 (edited) The lower edge of the roof panel above the cab should be horizontal, parallel with the other roof panel edges. All of the slope down to the cab's 'peak' occurs forward of this panel. The horn enclosure looks a little 'flat' at the front making me question the downward slope of the cab roof, maybe not quite steep enough? I think I get where you're coming from with that Dave. It looks like all of the drop should be ahead of the red line marked on the snap below. It's worth closer examination. Edited August 16, 2011 by Andy Y 1 Link to post Share on other sites More sharing options...
RMweb Gold Downendian Posted August 16, 2011 RMweb Gold Share Posted August 16, 2011 Hi Dave Thanks for the updated images. I understand from speaking to the Shawplan guys at the Bristol show that the are making new etches for the 52 walkways and fans. I asked about them for upgrading my Heljan fleet, and they told me to wait until these are produced (their new Warship etches are superb). Clearly they are researching the roof layout of a Western- Brian's recent pics on the Warship grille thread were highly helpful for me. Now if your new Western were to fit Shawplan etches as standard.........there's a thought! Neil 1 Link to post Share on other sites More sharing options...
S.A.C Martin Posted August 16, 2011 Share Posted August 16, 2011 As far as I can see, the front panel should be in parallel to the lower edge. I've marked out the two 90 degree angles which make the edges parallel in my edit (apologies Dave). EDIT: Ninja'd by Andy. Link to post Share on other sites More sharing options...
craigwelsh Posted August 16, 2011 Share Posted August 16, 2011 The roof of the cad is curving over the length of that panel by the look of it which is why the bottom edge isn't parallel. Anyone got a side on shot from a step ladder to show if that is really the case (I know the bottom edge should be parallel)? I guess this shows laser scanning is only useful if the CAD operator doesn't completely ###### around with the data.. Moving the roof grilles to the centreline being the ultimate example of that in the original views. Please make the walkways a separate fitting so that they can be easily replaced. Link to post Share on other sites More sharing options...
Rugd1022 Posted August 16, 2011 Share Posted August 16, 2011 Hi Dave, Welcome back! I'd agree with everything that Dave, Andy Y, Neil and S.A.C. Martin have said but would add that to me, the centre portion of the roof peak looks like it needs to be a touch 'flatter' at it's outer edge if that makes any sense.... your head on CAD shot captures the face of the loco very well (miles better than anything we've seen before), but the angle of the underside of that all important peak still looks to be sloping upwards a bit more than it should. I know we're probably talking minute differences in angles here considering the actual size of the finished model, but if you look at Andy Y's lovely shot of D1048 hopefully you can see what I'm getting at. I know you've scanned the real thing, but it still looks slightly out to my eyes. Perhaps it's just the 'two dimentioned-ness' of the CADs though as we're viewing them on a screen, any thoughts...? Overall it looks a real beauty, so count me in! Link to post Share on other sites More sharing options...
Rugd1022 Posted August 16, 2011 Share Posted August 16, 2011 A side on shot showing that roof panel above the cab... it's definitely parallel... 3 Link to post Share on other sites More sharing options...
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