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Post by Cro on Feb 17, 2015 16:27:49 GMT
What I still can't understand is A) how they ever managed to produce a working prototype of these and get funding thinking 'oh look how well these go together this is a great idea' and B) how if using CNC they managed to get it so so wrong.
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Post by Deleted on Feb 17, 2015 16:45:12 GMT
Hi Adam...from what I've read between the lines I think it was a case of chewing off more than they could chew...they should have got each prototype fully working and reliable before moving onto the next. They didn't and their reputation began to dive, perhaps they should have kept to fewer and more simpler designs until fully established. When you consider some of the loco's in their range they were far from being simple.
Pete
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Post by Cro on Feb 17, 2015 17:07:10 GMT
Pete,
Sounds about right, I mean Modelworks and Winson were a little before my time to a degree, I still remember seeing their stands at Ally Pally when going with Dad and saying "I want one of these" and I did eventually get one but got I wish I hadn't! Polly have it cracked with their Kit locos but I can understand wanting to try do prototypical locos but they just did it in all the wrong ways - I have a feeling the ex owner of Modelworks was at Ally Pally this year trying to sell Gauge 1 locos......
Adam
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Post by Deleted on Feb 17, 2015 17:53:25 GMT
You've not alone there Adam...I very nearly bought one of the kits back in 98..the Jubilee iirc, I decided against as at that time knowing little about live steam locomotives or Modelworks. I did receive their presentation brochure which looked pretty good to my untrained eye. Things came to a halt when discussing this dream of mine with SWMBO, well she had to draw the line somewhere, she had just let me buy my Porsche, so i was kind off taking the piss, mind you the car was her idea, she knew how I had always wanted such a car, two weeks after she suggested it there it was sitting on my drive....you need to move quickly in these situations...women can change their mind without warning.... Anyway what I did do was buy the plans for Doncaster instead , a decision that I have been most grateful for ever since, even more so due to my untrained eye. The rest is history...many year later I was asked to take a look at a Modelworks A4 buy a chap who needed someone to finish it for him, this was my first close up introduction to a modelworks model and one that I was able to judge very accurately having been building Doncaster for some years now. I was not at all impressed, far too blocky and none prototypical for me..the list of faults seemed endless and certainly more than the owners idea of just a bit of piping to do, alas i walked away, the boiler looked pretty sound though and I have heard some good reports of boilers but then I've also heard some bad ones too so I guess buyers were dependent as much on luck than anything else. Pete
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Post by alabaster on Feb 17, 2015 20:45:41 GMT
Pete,
Your summation of Winson is pretty accurate. It took way way too much on in the early days. I think genuinely shocked by the level of interest in a steam loco kit. The initial batch of 72 Britannias pretty much funded the future projects. Also Winson Engineering was a highly reputable builder of narrow gauge locomotives and carriages, it just couldn't cope with mass production which had to meet the phenomenal demand. Also there was an obsession with bringing all production in-house rather than buy in proven parts hence nearly all the fittings were machined.
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Post by andyhigham on Feb 17, 2015 21:09:10 GMT
A slight side track, one of our club members has an OS kit built Baldwin switcher. The quality is absolutely first rate, many of the bearings are ball and roller races and the baker valve gear is a work of art. Typical Japanese attention to detail.
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Post by Cro on Feb 20, 2015 11:00:49 GMT
So back to the fittings I have just received the photos of the first castings of the manifold in 7 1/4", very pleased so far. It has given me a few things to think about and mods to make but good progress so far. This is an image of the CAD model with the new runners added on to help wax melt out flow and metal flow for casting. And here are the castings. Adam
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Post by Deleted on Feb 20, 2015 11:09:35 GMT
that's a work of art Adam.....love the detail.. Pete
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Post by Roger on Feb 20, 2015 11:11:10 GMT
Very neat Adam. I'm intrigued by the fact that the fittings are cast into the body of it. Are these working outlets or just for show? If they are piped, how do the pipes seal?
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Post by Cro on Feb 20, 2015 11:13:56 GMT
Forgot to add, here is a little snippet of the machining drawing - don't want to give too much away Thanks Pete! Roger this should hopefully show you a bit more, they are all working fittings though, all shut offs are dummy except the main one
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Post by Roger on Feb 20, 2015 11:33:47 GMT
I think I see... the square flanged ones have the working connections, the others just get dummy pipes inserted into them?
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Post by Cro on Feb 20, 2015 11:44:22 GMT
Yes and no, the square flanges are as they seem the other two need small fittings made to either be soldered in or how I have planned it to be threaded in (male to male ) to take a nut and nipple for a pipe fitting - like this.
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Post by Roger on Feb 20, 2015 11:50:04 GMT
Ah, ok, I hadn't seen the real thing and didn't realise that the two with stubs on them weren't outlets.
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Post by Deleted on Feb 20, 2015 11:50:52 GMT
I've got a question about the functionality of scaled down components .
Different defining variables of a component get scaled by different factors when component is enlarged or reduced .
Some examples relevant to steam fittings : simple dimensions , flow area , valve sensitivity and allowable stress values all scale by different factors .
Add in things like access for controls and adequacy and access for fixings .
So do geometrically scaled down functional components actually work properly as is or do they require modification ?
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Post by Cro on Feb 20, 2015 12:07:35 GMT
I've got a question about the functionality of scaled down components . Different defining variables of a component get scaled by different factors when component is enlarged or reduced . Some examples relevant to steam fittings : simple dimensions , flow area , valve sensitivity and allowable stress values all scale by different factors . Add in things like access for controls and adequacy and access for fixings . So do geometrically scaled down functional components actually work properly as is or do they require modification ? So from the bits I have done so far the physical dimensions have purely been scaled down and been left as is for the majority of parts. When it comes own to things like fixtures and fittings dimensions need to be analysed once scaled to see if they will be suitable after casting or reduced to suit a specific dimensions - for example the small holes for bolting the square faces together are smaller than they would have been if done from scale but this is to allow for drilling and tapping the holes. When it comes to flow and so on, especially with the prototypes, its a bit of a trial on this one. Using a bit of common sense I try to make the passageways as large as possible to help. When I did the LMS brake valve most things worked out ok, the only scaling issue I had was with the ratio between surface areas on the Vacuum Piston and the Steam Brake valve rod, using the scale dimensions the pressure on the steam brake was too great for the Vacuum to over come it and hold the valve closed so some calculations had to be made with relation to what could physically fit within the body. By no means am I an expert in this but I like to apply some common sense with most parts - what I do is model the item in full size first, scale it down and then re-asses things like porting, valves and so on and work out what I can get away with to make it function correctly if I were making it as simple as possible. I am currently tackling the Duplex Steam Valve which will take some thinking when it comes to casting the internal porting and what will need machining. Hope that answers your question? Adam
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Feb 20, 2015 12:29:09 GMT
hi michael, good to see you back! you pose a very interesting question which causes many of us a dilema. i would add to your factors a few more such as strength, ease of connecting/disconnecting, and can you get a spanner on the relevant bits. if fittings are screwed in one also has to sure this can be done without a 'foul' with something else. i dont know the answer to some of the factors you pose. i like to see fittings in their correct location ie as near enough the arrangement of the fullsize backhead. don young was very good at this, but martin evans and LBSC particularly bad. martin evans had no excuse IMHO for designing some of the most atrocious backheads and fittings for his locos. i suppose the starting point is the water level gauge(s). i havent carried out any experiments on very small dia glass- it's not something i want to experiment with, and would be very interested to hear if anyone else has done any experiments. anyway those i made for Stepney are 3.16" dia glass and as compact as i could make and are a lot smaller externally than most 'standard' commercial fittings. on a 5"g or 3.5"g this rather dictates the proportions for everything else for a working loco. (it would IMHO look a bit silly to have exact scale cab fittings surrounding a very over scale water gauge). the whistle valve is also problematic to make reasonably small and yet function properly. i do not like handles for cab fittings fitted via anything other than squares on the spindles. a 3/32" spindle results in just over a 1/16" square which is the limit of my skills, and even in stainless the limit of strength. i have always thought that most 'standard' commercial fittings are unnecessarily large and chunky, as well as being expensive for what they are. modeleng.proboards.com/thread/9467/scale-boiler-fittings?page=5hi adam, the new castings look extremely well made and detailed! cheers, julian
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Post by Deleted on Feb 20, 2015 12:31:50 GMT
Thank you both for your answers .
Conventional wisdom always was in model engineering that " nature can't be scaled " . I suppose that is true but people like LBSC and Martin Evans always used it as an excuse to design enormous ugly fittings .
People like Amesbury started to look at fittings afresh and produced some near scale but quite functional fittings for his engines - in particular for his GW tank and Caledonian engine .
He did apparently make a cryptic remark once though that he never had a run where he didn't have to mend one of his fittings afterwards !
You can't scale down clumsy fingers perhaps .
Incidentally Amesbury managed to make a working speedometer for cab of his Britannia .
Michael .
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Post by Cro on Feb 20, 2015 12:39:47 GMT
With a lot of it its a bit of give and take as to how far you go really. I could have made all the shut offs working and so on (I may do one for the ...fun... of it) but that I felt would limit the flow for the two end fittings as you are then introducing internal walls around those fittings.
Julian those water gauges look lovely and I totally agree it only takes on obscure or overly large item in a cab to ruin its whole appeal, pressure gauges are another one.
Adam
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Post by Deleted on Feb 20, 2015 13:11:09 GMT
With a lot of it its a bit of give and take as to how far you go really. I could have made all the shut offs working and so on (I may do one for the ...fun... of it) but that I felt would limit the flow for the two end fittings as you are then introducing internal walls around those fittings. Julian those water gauges look lovely and I totally agree it only takes on obscure or overly large item in a cab to ruin its whole appeal, pressure gauges are another one. Adam I agree fully about scale fittings and in particular water gauges and pressure gauges...I shall work very, very hard to make my own pressure gauges as close to scale size as possible, including the duplex vacuum gauge, I expect to spend an awful lot of time on these and have to say that I'm looking forward to it very much. Pete
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Post by Cro on Feb 20, 2015 13:32:47 GMT
Pete,
A chap in our club has just finished a duplex vacuum gauge and done articles in our news letter, if you like I can get hold of them and email them too you, If I go back through my emails I may already have them.
Adam
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