RMweb Premium Andy Keane Posted June 27, 2023 Author RMweb Premium Share Posted June 27, 2023 (edited) 3 minutes ago, Neal Ball said: That would be good Andy, yes please! How many others might be interested I wonder…. A single etch starts at about £120 because of set up costs but after that much less. The prints of the base would be only a few pounds each but many suppliers have a minimum order of £25 or so. To get to £30 per kit we would probably need around eight buyers. Of course the real cost is the time in CAD but I will certainly be doing this if I cannot get access to the models already made. I am generally happy to share my STL files for people on RMweb to use in a non-commercial way. Andy Edited June 27, 2023 by Andy Keane 3 1 Link to post Share on other sites More sharing options...
RMweb Premium Neal Ball Posted June 27, 2023 RMweb Premium Share Posted June 27, 2023 (edited) 4 hours ago, Andy Keane said: A single etch starts at about £120 because of set up costs but after that much less. The prints of the base would be only a few pounds each but many suppliers have a minimum order of £25 or so. To get to £30 per kit we would probably need around eight buyers. Of course the real cost is the time in CAD but I will certainly be doing this if I cannot get access to the models already made. I am generally happy to share my STL files for people on RMweb to use in a non-commercial way. Andy Thanks Andy, I will DM you in the morning. Edited June 27, 2023 by Neal Ball Typo 1 Link to post Share on other sites More sharing options...
RMweb Gold Graham T Posted June 27, 2023 RMweb Gold Share Posted June 27, 2023 I'd probably be interested in one of these for CR Mk II. 1 1 Link to post Share on other sites More sharing options...
RMweb Gold Harlequin Posted June 27, 2023 RMweb Gold Share Posted June 27, 2023 Put me on the list, too, please. Let me know if I can help with the CAD or test prints. 1 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 27, 2023 Author RMweb Premium Share Posted June 27, 2023 If we are to make a crane kit we need to agree on how to model the jib. No doubt the most accurate method would be scratch building from brass angle and strip, soldered up on a jig. But would people want to do that? Next up would be brass etches that fix the main structure and then decorate these, either with soldered brass strip or glued on 3D printed parts. The quickest approach is a full 3D print but this would be fragile. A half way house would be a 3D print strengthened with strategically placed brass rods. We need to decide this before starting the CAD. If we avoid an etch it will save a fair bit of the cost. Could people let me have their views please? Andy 1 Link to post Share on other sites More sharing options...
RMweb Gold kingmender Posted June 27, 2023 RMweb Gold Share Posted June 27, 2023 Morning Andy I'd go for a brass etch for the jib. Angles can be folded from half etch lines and reinforced wwith solder. Makes a robust object that by its very nature tends to get knocked during layout maintenance and track cleaning. Put me down for 2 please. Rodger 1 1 Link to post Share on other sites More sharing options...
RMweb Premium Neal Ball Posted June 27, 2023 RMweb Premium Share Posted June 27, 2023 Looks as if that’s 6 straight away @Andy Keane and we’ve not even advertised yet! 1 Link to post Share on other sites More sharing options...
BenL Posted June 27, 2023 Share Posted June 27, 2023 A vote from me for the 3D print reinforced as necessary. I have got a few prototype pics from a couple of different books if that would help at all. 1 Link to post Share on other sites More sharing options...
RMweb Premium Neal Ball Posted June 27, 2023 RMweb Premium Share Posted June 27, 2023 45 minutes ago, BenL said: A vote from me for the 3D print reinforced as necessary. I have got a few prototype pics from a couple of different books if that would help at all. 7 then. 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 8 hours ago, BenL said: A vote from me for the 3D print reinforced as necessary. I have got a few prototype pics from a couple of different books if that would help at all. Please PM me all and any photos. Although I have the drawings photos are invaluable. thanks Andy 2 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 My current thinking is a printed base with the option of either a printed jib or an etch based one for those who want a more rugged model and have the patience to assemble it. Does that sound like a plan? 2 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 8 hours ago, Neal Ball said: we’ve not even advertised Neal, not sure how one would advertise or exactly to whom? 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 Another thought is a 3D metal print of the jib. I have a friend who works in medicine and they 3D print stents that are tiny and very intricate in titanium for example. I will try and find out what is possible and at what cost. 2 1 Link to post Share on other sites More sharing options...
RMweb Gold Graham T Posted June 28, 2023 RMweb Gold Share Posted June 28, 2023 An etched jib would also be my preference. I know I'd break a resin one... 1 Link to post Share on other sites More sharing options...
RMweb Premium Mike_Walker Posted June 28, 2023 RMweb Premium Share Posted June 28, 2023 Whilst I don't have a requirement for a crane, is this view of the 6 ton crane at Marlow (installed circa 1940) of any use? 5 2 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 (edited) On 27/06/2023 at 03:44, St Enodoc said: Ah, but has it got seven strands? So this is what MSE signal wire looks like on a 20 foot roller spacing on my platform edge. I think if it were matt not shiny it would be even harder to see! Edited June 28, 2023 by Andy Keane 3 2 2 Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted June 28, 2023 RMweb Gold Share Posted June 28, 2023 34 minutes ago, Andy Keane said: So this is what MSE signal wire looks like on a 20 foot roller spacing on my platform edge. I think if it were matt not shiny it would be even harder to see! I was about to say “What wire?” when I managed to make it out. :-) Paul. 1 4 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 28, 2023 Author RMweb Premium Share Posted June 28, 2023 (edited) I have made some progress on the crane jib CAD model, though still a fair way to go: Edited June 28, 2023 by Andy Keane 4 6 1 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 30, 2023 Author RMweb Premium Share Posted June 30, 2023 This is the finished jib model. Whether we can actually make one remains to be seen! 2 4 3 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 30, 2023 Author RMweb Premium Share Posted June 30, 2023 For those of you interested in a 6 ton yard crane model it is not clear if printing a correct scale model in resin will be possible - most people think about 0.75mm is the smallest thickness it is sensible to print. The diagonal straps on the crane are 2" by 0.5" which comes out as 0.67 x 0.17 mm. This is just about feasible in brass strip but clearly not in a resin print. This leaves two options: leave all the thin detail out and just print a base frame to which brass bits can be glued (or go for a brass etch frame and add the details to that) or stick with a 3D print but alter the dimensions to make the features thick enough to be workable - so those diagonal straps would end up a square section for example. This would not look so nice of course. Views? 2 1 Link to post Share on other sites More sharing options...
MrWolf Posted June 30, 2023 Share Posted June 30, 2023 Would it be possible to make those cross braces as a shallow triangular section which would fool the eye but give a greater cross sectional dimension that would make a print more viable? It was something that @chuffinghell and I discussed when working out the lower door runner on the GWR CC7 which has to stand off the solebars. Link to post Share on other sites More sharing options...
RMweb Gold chuffinghell Posted June 30, 2023 RMweb Gold Share Posted June 30, 2023 (edited) 13 minutes ago, MrWolf said: Would it be possible to make those cross braces as a shallow triangular section which would fool the eye but give a greater cross sectional dimension that would make a print more viable? It was something that @chuffinghell and I discussed when working out the lower door runner on the GWR CC7 which has to stand off the solebars. I used optical confusion, the rail is only thin where it is visible The rail is much thicker where you can't see it Edited June 30, 2023 by chuffinghell 3 1 3 Link to post Share on other sites More sharing options...
MrWolf Posted June 30, 2023 Share Posted June 30, 2023 Thanks, that's the kind of thing I'm thinking, a flattened isosceles triangle would give strength and thin edges but be difficult to detect once painted and on the layout. 1 Link to post Share on other sites More sharing options...
RMweb Gold chuffinghell Posted June 30, 2023 RMweb Gold Share Posted June 30, 2023 (edited) 44 minutes ago, MrWolf said: Thanks, that's the kind of thing I'm thinking, a flattened isosceles triangle would give strength and thin edges but be difficult to detect once painted and on the layout. the same 'model' viewed from the front and back.... ....shameful trickery! 🤪 I've found that you have to over exaggerate the details details. My CC2 for example looks quite 'chunky' on the drawing.... ....but looks okay(ish) on the layout Edited June 30, 2023 by chuffinghell 2 5 Link to post Share on other sites More sharing options...
RMweb Premium Andy Keane Posted June 30, 2023 Author RMweb Premium Share Posted June 30, 2023 These sorts of tricks will help but remember even the front will be only 0.67mm wide. So I think it would need to be thicker in both directions. Also all the L sections will probably end up as square sections. Will that matter? I am no expert on printers, though I can drive CAD. 1 Link to post Share on other sites More sharing options...
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