ThePurplePrimer Posted April 20, 2014 Share Posted April 20, 2014 Hi Guys I am now onto starting my 2nd 7mm NG loco and I hope something a little better than my first one. Now I would like to claim the disclaimer that this loco is a freelance job but I want it to look like it could have been a real one - ie it needs to be credible Now the chassis is an RTR one ( and I am going to use this one ) and I have little desire to do much to it apart from cutting off the front and rear buffer beams I would really like to use this body style to fit my railway's back story so I think what I am really asking is if you feel the proportions look about right. The cylinder thingy ( I think that's what it's called? ) isn't quite under the chimney's centreline - is that acceptable It is going to be 0-16.5 7mm scale and is a freelance British outline - but the designer of my railways locos (Stan Dorsmein) may well have some German influences too PS - Wheelbase is 29mm Link to post Share on other sites More sharing options...
Giles Posted April 20, 2014 Share Posted April 20, 2014 Hi Rob, Two things. The centre line of the cylinders is generally directly below the centreline of the chimney for sound engineering reasons - most often the direct passage of the exhaust from the cylinders (centre thereof) to the blast-pipe (centred under the chimney. There are of course exceptions to this where the better compromise necessitates a misalignment, but the majority are built this way for this reason. Secondly, your smoke box is drawn too shallow, and should be almost half as deep (wide, on the drawing) again. The gasses drawn through the boiler are entrained by the exhaust blast, and sucked up through the chimney, but this all takes some room to happen smoothly. If the smoke box is not of adequate size, the boiler will not steam properly. Looking at photos and drawings of existing engines will give you a clue regarding proportions. I don't recall a smoke box shorter than the cylinders they served, and often a bit longer. Best, Giles Link to post Share on other sites More sharing options...
ThePurplePrimer Posted April 20, 2014 Author Share Posted April 20, 2014 Thanks Giles I really appreciate your feedback I have changed the picture a bit to fit the suggestions made by you and others on the NG forum too I agree that this looks much better Interestingly everything above the footplate on the original is a scale drawing of Victoria from the. Rye and Camber and that how big the smoke box was - I still agree that to my eye ( which is very untrained ) it looks wrong and now looks better a bit deeper Link to post Share on other sites More sharing options...
PLD Posted April 20, 2014 Share Posted April 20, 2014 To be honest, I've never understoood why so many narrow gauge modellers insist on 'reinventing the wheel' by desiging their own freelance locos which are invariably mechically unsound or impossibly over complicated for the type of line they proport to be modelling. This is part of why narrow gauge modelling is often not taken seriously by modellers with broader horizons... Why not just copy a prototype design and assume the builders simply chose something from the loco builders standard calalogue (possibly with a few cosmetic variations to taste) - thats what all but the best funded or most self sufficient prototypes did.. Link to post Share on other sites More sharing options...
Matador Posted April 24, 2014 Share Posted April 24, 2014 What Chassis is that David Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted April 24, 2014 RMweb Gold Share Posted April 24, 2014 To be honest, I've never understoood why so many narrow gauge modellers insist on 'reinventing the wheel' by desiging their own freelance locos which are invariably mechically unsound or impossibly over complicated for the type of line they proport to be modelling. This is part of why narrow gauge modelling is often not taken seriously by modellers with broader horizons... Why not just copy a prototype design and assume the builders simply chose something from the loco builders standard calalogue (possibly with a few cosmetic variations to taste) - thats what all but the best funded or most self sufficient prototypes did.. Because it's fun? Link to post Share on other sites More sharing options...
ThePurplePrimer Posted April 24, 2014 Author Share Posted April 24, 2014 What Chassis is that David Hi David It's a Liliput HO fireless loco I will put some more pictures up tomorrow Link to post Share on other sites More sharing options...
PLD Posted April 24, 2014 Share Posted April 24, 2014 Because it's fun? But unless your name is Emmett, is it any less 'fun' to build to realistic proportions?? Link to post Share on other sites More sharing options...
ThePurplePrimer Posted April 24, 2014 Author Share Posted April 24, 2014 But unless your name is Emmett, is it any less 'fun' to build to realistic proportions?? Hello PLD I am genuinely interested in your opinion. Are you saying that you feel the design I have shown above is not proportioned realistically ? If that is what you are saying, I am keen to know what exactly you feel looks wrong about the designs proportions as I am very open to suggestions. Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted April 24, 2014 RMweb Gold Share Posted April 24, 2014 But unless your name is Emmett, is it any less 'fun' to build to realistic proportions?? Not at all. One is not fun to the exclusion of the other. Link to post Share on other sites More sharing options...
Roger.s Posted April 24, 2014 Share Posted April 24, 2014 But unless your name is Emmett, is it any less 'fun' to build to realistic proportions?? Any fool, (ok most fools) can build an unrealistic loco. It takes skill to make it realistic and believable and the likes of Emmett to make it totally unrealistic and still believable! Link to post Share on other sites More sharing options...
bécasse Posted April 25, 2014 Share Posted April 25, 2014 Your design is surprisingly realistic, especially as the rear axle fits neatly in front of the fire box (a common error on concoctions!). The top looks like the Bagnall it is copied from, and Bagnall usually used an underslung version of the valve gear, but a customer could have specified it that way and Bagnall would have built it as specified. The loco might look better with a small pony truck under the cab, and it certainly would have run better with one, an important consideration if it was intended for light passenger work, but it isn't impossible as an 0-4-0T. (The R&C locos were 0-6-0T.) Link to post Share on other sites More sharing options...
sir douglas Posted April 25, 2014 Share Posted April 25, 2014 rye & camber engines (except the simplex) were 2-4-0 Link to post Share on other sites More sharing options...
RMweb Premium New Haven Neil Posted April 25, 2014 RMweb Premium Share Posted April 25, 2014 Bagnalls made many locos with a marine style concentric tubular firebox, therefore the placement of the axle is irrelevant if it is the case it is a Bagnall? See 'Sea Lion'.... ;-) Link to post Share on other sites More sharing options...
ThePurplePrimer Posted April 25, 2014 Author Share Posted April 25, 2014 Hi Neil Can you tell me more about that firebox design please Link to post Share on other sites More sharing options...
sir douglas Posted April 25, 2014 Share Posted April 25, 2014 A marine boiler is one that has the firebox compacted to save space, and does not need to project down into the frame, although because of the reduced size of the firebox it is harder to maintain steam with a marine boiler than with a conventional one, Arthur Heywood found this out on his engines, the ravenglass & eskdale later found this problem when they got his engines in about 1912 after his death, the engines were worked hard on their freight traffic but could not maintain steam on the line's gradients, He chose a marine boiler because of his radial motion to show it, here is a replica of one of Heywoods engines half built http://www.7-8ths.info/index.php?action=dlattach;topic=16683387.0;attach=116634;image As they have said, it would be best to have a trailing wheel, In my eyes it would make the loco look more like a Kerr Stuart "Sky lark" class https://www.google.co.uk/search?q=kerr+stuart+skylark&tbm=isch&tbo=u&source=univ&sa=X&ei=rElaU4r8KIi30QWZkIDgCQ&ved=0CCsQsAQ&biw=1024&bih=484 Also, Bagnall had their own valve gear which was standard on their engines, unless stated otherwise. I have a Plateway Press copy of a Bagnall catalogue, because of copyright I wont post any of it here but I could show some of the engines by PM. Link to post Share on other sites More sharing options...
bécasse Posted April 25, 2014 Share Posted April 25, 2014 The two Rye & Camber steam locos had conventional copper fireboxes even though the basically level grades and light loadings on the line might well have suited locos with a marine firebox. The rear driving axle was situated to the rear of the firebox as it would have been on an 0-6-0T. Although Bagnall's had their own designs of valve gear - initially Baguley and, after that gentleman left the Company, Bagnall-Price - the Rye & Camber locos were fitted with inside Stephenson link gear; furthermore Bagnall's had, by the Great War, adopted Walschaerts valve gear for much of their production, even though the underslung links they tended to fit were vulnerable to damage from contact with obstructions. Link to post Share on other sites More sharing options...
Talltim Posted April 25, 2014 Share Posted April 25, 2014 Thanks Giles I really appreciate your feedback I have changed the picture a bit to fit the suggestions made by you and others on the NG forum too I agree that this looks much better image.jpg Interestingly everything above the footplate on the original is a scale drawing of Victoria from the. Rye and Camber and that how big the smoke box was - I still agree that to my eye ( which is very untrained ) it looks wrong and now looks better a bit deeper The extended smokebox does look better and solves your smokebox to cylinder centreline issue as well Link to post Share on other sites More sharing options...
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