jma1009
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Post by jma1009 on May 19, 2014 17:04:09 GMT
a couple of pics of the completed inner firebox assembly after silver soldering in position the inner firebox doorplate yesterday afternoon. the boiler was placed in the same position and set up as doing the side stays ie 'bottom up' and the firehole ring and most of the inside of the firebox filled with thermalite pieces. the inside was also fluxed up at the back. 2 easyflo2 rings of silver solder rod were placed around the phos bronze screw heads - these can be seen in the second pic on what is the top of the rear flange of the inner firebox doorplate. the whole lot was then heated up from outside with the flame being directed at the inner firebox doorplate. you do tend to get a bit of a tendancy for the silver solder to flow by gravity but this isnt too much of a problem and helps get a nice fillet around the curved joints lots more phos bronze bushes to make next and the rear section of the foundation ring. the backhead still fits perfectly im pleased to say! cheers, julian
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uuu
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Post by uuu on May 27, 2014 20:35:30 GMT
It's interesting to see how boiler construction techniques and design details have developed and improved. Your main steam bush is a mighty thing. The Maisie boiler we have at the Pump House (this may be off a loco you've steamed) just had a hole. No soldered in bush - just a threaded hole. Not that the thread was actually doing anything - the steam manifold was being held in place by the tension of the pipe from the regulator - when that was removed you could just push it in and out. Yet the boiler had been working! Firehole door - just screwed in, no bushes. Blowdown valves - screwed in. Water guage - screwed in.
Wilf
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jma1009
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Post by jma1009 on Jun 4, 2014 0:04:06 GMT
hi brian,
thanks for your kind comments!
i use ME threads for all boiler stuff. ive quite a few odd sizes amassed over the years but all the above are bog standard ie 5/16 x 32 tpi ME thread and 1/4" x 40 tpi ME thread. the blower valve bush on the smokebox tubeplate is threaded 3/8" x 40 tpi to match the 1/4" x 40 tpi thread on the hollow longitudinal blower stay/pipe, 3/8" x 40 tpi being one of the 'special' sizes. you can see the rear end of the blower pipe poking through the backhead. it will get threaded and fitted to size in due course when all the bushes etc and backhead have been silver soldered to the backhead and the backhead silver soldered in position. so only 2 more (hopefully) heat ups required - sub assembly of bushes on backhead with high melting point silverflo 24, then backhead to boiler plus rear foundation ring and all remaining backhead stays and the water gauge elbows and the firehole ring with easyflo 2, and the longitudinal stays.
the 'spare' fitting of the water gauge top fitting has a 5/16 x 32 tpi thread for the gland nut. on STEPNEY's fittings i reckon i can go down to 9/32" x 32 tpi (a special size) so having 5/16 AF hex gland nuts instead of 3/8 AF hex.
i was always taught (many years ago) to try and make boiler fittings as scale and small as possible and practicable, by someone who made 'chunky' LBSC type fittings commercially for the ME trade, but made his own fittings for his own locos of much finer proportions! then along came roy amesbury who showed what really could be done in miniature with loco fittings! not all of what roy advocated is practicable for us mere mortals, but don young in his later designs showed what was still possible and practical. unfortunately martin evans never followed suit. incidentally i have some early bassett lowke fittings (and injectors) and before LBSC you would be shocked by how enormous and chunky and large pre LBSC boiler fittings were!
cheers, julian
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jma1009
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Post by jma1009 on Jun 14, 2014 22:18:05 GMT
despite the hot weather today decided to have a go at fitting the backhead to the boiler of STEPNEY, being the final silver soldering stage. first job was to check that the propane bottle was still heavy! then fluxing up the bits and fitting same to the backhead etc. around 4pm it clouded over so lit the propane torch. after 10-15 mins of directing the heat on the firehole ring the job was up to heat then silver soldered up the backhead stays then the firehole ring then the backhead bushes and longitudinal stay ends, then the backhead to outer wrapper joint and water gauge top elbows and manifold bush, then the rear section of the foundation ring. all went ok and nothing missed. before fluxing up the rear section of the foundation ring and backhead and outer wrapper were crosshatched with a triangular file. anyway here's a few pics. the first pic shows the boiler fluxed up and ready for silver soldering with a piece of thermalite cut to size shoved up the inside of the firebox. second pic is the boiler still hot after silver soldering. the other pics are of the finished joints (which havent been cleaned up/tidied up yet) but the longitudinal stays have been cut to length, and the last pic ive filed the backhead phos bronze stays down. i wasnt too impressed with the cupalloys supposedly 'same as easyflo 2' silver solder used on the firebox doorplate so decided to use same on the backhead etc to use some of it up rather than use what little ive left of genuine easyflo 2. next job is to open out the threads on the boiler bushes to full depth and fit threaded plugs etc and the inner dome etc for my own hydraulic test. no celebrations till then! cheers, julian
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jma1009
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Post by jma1009 on Jun 14, 2014 22:43:22 GMT
a few additional points...
the backhead and remaining joint on the rear section of the foundation ring were done with the rear of the boiler pointing upwards which requires directing the heat downwards. only apply the silver solder when the whole lot is up to heat.
LBSC and martin evans and others say peen over the edge of the firehole ring. this is stupid as prevents the silver solder flowing through this joint with the backhead and will result in just a surface flow of silver solder which has little strength. i added a chamfer to the edge of the opening to the firehole ring on the backhead and also on all the stay holes and edge of the rear section of the foundation ring.
the solid phos bronze longitudinal stays are silver soldered direct to the smokebox tubeplate and backhead which considerably simplifies construction plus saves time, and is also what the professionals do.
cheers, julian
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jma1009
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Post by jma1009 on Jun 22, 2014 22:14:50 GMT
thanks pete and alan for the above very kind comments.
i havent done much in the workshop this last week - apart from repair the electric hedge clipper cable i'd 'clipped' through!
the boiler has been regularly pumped up. the regulator body is temporarily fitted and the 2 bolts fixing same have only a smear of hermatite sealant at the moment and drip occasionally - it only takes a few drips to knock the hydraulic pressure back. im trying to keep the pressure up so the plates can settle down and harden up from their annealed state.
i have tidied up a few runs of the silver solder. i have also nearly finished working out the details of the Stroudley firehole door parts. quite a fiendish contrivance in miniature! i nearly made the mistake of fitting the tray above the firehole (to which the firehole door assembly is attached to) in the scale position immediately above the firehole, then realised i'd never be able to see the fire! so it will be a bit higher than scale, as a good view of the fire i regard as very important when driving (this would be a problem with anyone following the 7.25"g don young NEWPORT design).
Jim Scott has very kindly sent me a spare set of superheater elements of radiant stainless type made for his own 5"g terrier EARLSWOOD, for which i am incredibly grateful. STEPNEY will therefore be my first loco with radiant superheaters.
cheers, julian
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jma1009
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Post by jma1009 on Jun 25, 2014 21:04:36 GMT
hi andrew, ive started the firehole door assembly and have made the tray which has the hinges for the door attached. a mini reverser goes on a quadrant on the lefthand side to open the door inwards here's a pic of STEPNEY's tray and firehole door in fullsize. it has to be unbolted and removed to allow inspection of the inner firebox ive got to make the door itself next which will be fun and games. cheers, julian
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jma1009
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Post by jma1009 on Jun 26, 2014 7:29:05 GMT
George Ray or Ben will have to help here, but the Stroudley firehole door is almost identical to the Webb firehole door.
the door opens inwards and so no deflector plate is needed. i suppose also you dont have to fully open the door if only a small amount of coal is being added.
cheers, julian
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Post by Deleted on Jun 26, 2014 10:55:53 GMT
See if anyone can find a pic of Met 1s firehole door, it's kinda the same idea as the stroudley flap apart from its a round hole with a round dish shape door which seals against the inside of the firebox when shut!! Totally mad!
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jma1009
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Post by jma1009 on Jun 27, 2014 0:10:48 GMT
here's the nearly completed Stroudley type firehole door fitted to the hinge block and tray assembly. it has had countless trial fits in the firehole on the boiler taking a bit off the steel here and there till fits and works ok. the firehole door is a steel fabrication sifbronzed together. i wouldnt normally bother describing such things as firehole doors, but ive never seen a Stroudley/Webb type firehole door in 5"g and is making an interesting project. cheers, julian
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Post by Jim Scott on Jun 27, 2014 9:35:40 GMT
Hmmmmm. The more this thread progresses the more disgruntled I get with the 'sow's ear' that I built (about 1980-ish) to Martin Evan's original boiler design. Thanks Ben for the pointer to the Met 1 round firehole door and Julian for the photos, I will eventually have to do something along these lines for Earlswood.
Julian, going back a page or two to your comments re loco plates. DC's are the best commercial plates I have seen, mine are passable for a first attempt. It is not too difficult to etch brass plates to a reasonable standard.
Tomorrow it's 'Happy Birthday' to "BOXHILL by Martin Evans". Three years old -doesn't time fly......
Cheers
Jim
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jma1009
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Post by jma1009 on Jun 28, 2014 21:31:36 GMT
hi jim! gosh 3 years! ive made the operating handle and mark 1 latch handle for the firehole door out of stainless. made a cock up with the slot in the latch handle whereas the slot should be in the operating handle! mark 2 tomorrow hopefully! 3/64" slots not my favourite thing to do in stainless! (btw all my stainless plate is very tough stuff ex shipyards on the IW!). the operating handle is a 'miniature' version of my scale Stroudley reverser lever. cheers, julian
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jma1009
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Post by jma1009 on Jun 28, 2014 22:00:33 GMT
hi pete and john, many thanks for your very kind comments! CNC free zone here! i was a bit worried that the Stroudley type firehole door would be totally impractical in miniature but ive tried it out and it works ok including trying it with a few different sizes of shovels ive got and angle of viewing from the driving position. the bottom flap referred to by Ben and George Ray will get fixed to the cab floor to avoid adding screwed fixings to the boiler backhead. cheers, julian
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jma1009
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Post by jma1009 on Jun 29, 2014 10:47:41 GMT
glad you all like the firehole door thingy especially Ben though it isnt finished yet.
Roger's observation is interesting. STEPNEY is intended as a working loco not a showcase model and there is always a judgement to be made about the practicalities of making 'scale' bits on a loco so that they can be operated, be reliable, and durable, and if necessary repaired.
cheers, julian
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Post by davebreeze on Jul 12, 2014 21:56:16 GMT
I'd never seen the Stroudley firehole door before seeing Julian's on here, but I've been reading a book on Caledonian Railway locos I picked up in a second hand shop and it appears that the Stroudley door was standard (or common at least) on Caley locos too. Dugald Drummond introduced it on the 'Jumbo' 0-6-0 goods engines in the 1880's and you can see it in the cab drawings in Caley locos right up to 1922.
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Post by Roger on Feb 19, 2015 19:26:19 GMT
You may dread doing it, but it's most certainly worth the effort. It's these sort of details, like your firehole door, that catch the eye and really make it special. I wouldn't have thought of Silver Soldering the ends on, I think I would have make them from solid and taken much longer to get it done.
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Post by Deleted on Feb 20, 2015 0:35:22 GMT
You may dread doing it, but it's most certainly worth the effort. It's these sort of details, like your firehole door, that catch the eye and really make it special. I wouldn't have thought of Silver Soldering the ends on, I think I would have make them from solid and taken much longer to get it done. ------------- Hi Roger, well that's the difference between a "Production" approach and the "Modeler's" one I would say...
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dscott
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Post by dscott on Oct 17, 2018 0:21:49 GMT
Terriers or Roo ers came up in conversations twice over our Weekend and Friday at the Bluebell? Friends started a quiz and within did various footplate poses as one of them Chris Eden-Green had a model made by Rapid Prototyping. So kneeling down on the floor, cramped up with left hand on a lever and other on a shovel. Got a universal Terrier from all. Sunday on the S15 for an invited few minutes Got "They are Roo ers wi out the TEA!!" When I described my build collection. As of course The S15 has a levered Firehole door!!
David still floating from the experience. And Lily who enjoyed the countryside and meeting pets on the stations.
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Post by midlandp4 on Mar 17, 2023 10:26:14 GMT
i drilled the holes for the stays in the backhead yesterday evening (carefully!) as the stays have to be silver soldered already to the inner firebox doorplate for propane (see pics 30th april) hopefully the need for the centres in the end will become apparent. you drill undersize first to see if the centres are central in the drilled hole and draw over if required. i got 10 out of the 15 spot on, with the remaining 5 needing just a little bit of drawing over. then opened out to No.22 for the 5/32" dia stay ends. they will get opened out to No.21 before silver soldering the backhead plus countersinking. exactly the same as fitting the firehole ring to the backhead, just more work involved and careful 'fitting'. might get the inner firebox doorplate silver soldered to the inner firebox this weekend if i have time. i would like to fit a scale Stroudley type firehole door which is quite a fiendish and fiddly device in miniature. it is a flap that opens inwards into the firebox hinged at the top, similar to the Webb firehole door. i might have a slight deviation and have a go at making a trial one out of brass to see if it is workable in miniature, before progressing further with silver soldering on the boiler. the Stroudley firehole door was quite a feature of the fullsize locos. i have never seen a working 5"g version before! cheers, julian Hello Julian, did you manage to construct a scale operating firedoor for your Terrier? If so, would you be generous enough to share your results in the form of photos or plans? I am currently building a Martin Evans 5” gauge A1 and would dearly love to replicate the prototype door. I have found some photos from video clips on YouTube which show the lever with ratchet with which the fireman opens and closes the door. But I cannot find details of the linkages which connect the base of the operating lever to the fire door. Or how and where the lever and ratchet is attached to the backhead. Details of the door hinges would be a bonus. I live in Australia and am a bit too ancient to travel now, being in my late 70’s. So I have asked people at the NRM if someone could take some photos from the footplate of Boxhill. But it is currently inaccessible due to renovations. I have not been able to find an engineering drawing of the Terrier firedoor at the NRM either. I have had no luck after contacting the Bluebell Railway or Kent & East Sussex Railway. Any assistance you could give me would be gratefully appreciated. Kind Regards, Bruce Boldner
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uuu
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Post by uuu on Mar 18, 2023 10:56:59 GMT
Yes - I'll second that. And I failed to mention in my last post - having searched for, and found, the firehole door - how brilliant it is! So it needs to see some action.
Wilf
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