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Post by Roger on Nov 16, 2018 23:46:10 GMT
Thanks for the kind comments guys, it's much appreciated. I've spent the whole evening just setting up and drilling the holes in both of the infills between the backhead and the firebox cladding. It's been very fiddly to get it right, but I think it's good enough now.  20181116_190825 by Roger Froud, on Flickr The holes are 1.4mm clearance for M1.4 bolts, but the intention is to open them out in the steel cladding and to add hank bushes.  20181116_191032 by Roger Froud, on Flickr  20181116_203003 by Roger Froud, on Flickr I've drilled the holes in the backhead, but this all needs assembling and spotting through with it in position.  20181116_224837 by Roger Froud, on Flickr |
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Post by Oily Rag on Nov 17, 2018 20:41:30 GMT
I can only ponder if we gave Rodger 500 photos, 200 works drawings of a prototype, here is wages for ten years, what a marvelous result would we behold
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Post by Roger on Nov 18, 2018 9:09:04 GMT
I can only ponder if we gave Rodger 500 photos, 200 works drawings of a prototype, here is wages for ten years, what a marvelous result would we beholdHi Daz, An interesting thought, but the honest answer is that life's too short for me to spend time on another projects of this magnitude! |
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Post by Roger on Nov 18, 2018 18:37:20 GMT
The 0.5mm thick Steel cladding isn't thick enough for a thread, so the 1.4mm holes are being opened up to 2.4mm to take Phosphor Bronze clinch bushes. Holding it is tricky but I really dislike holding this sort of thing by hand, it's a recipe for disaster. The clamps aren't long enough, so I'm improvising a longer one with a piece of bar.  20181118_125735 by Roger Froud, on Flickr  20181118_125742 by Roger Froud, on Flickr They're a bit close to the edge in places where the cutout isn't quite right, but it's not important since none of this is visible. The bushes are crimped lightly with the rivet press...  20181118_163724 by Roger Froud, on Flickr ... then soft soldered with the monster iron. It's a bit messy on this side, but there's little point in doing much about that since it's hidden.  20181118_175730 by Roger Froud, on Flickr Flux is so corrosive I don't want to leave the Steel plate bare, so I've wiped it down thoroughly with White Spirit after tidying up the bushes with needle files and giving the surface a quick going over with wet & dry. I've given it a coat of Isopon Zinc 182 primer which seems to get a good grip.  20181118_181004 by Roger Froud, on Flickr |
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Post by terrier060 on Nov 18, 2018 20:30:35 GMT
Hi Roger - I have been so absorbed with my works plates that I have not been following you very closely, but as ever a joy to behold how you set things up. Most people would have built three models in the time you spend, but what a difference! You will find it hard to get it dirty on the track!
I like the use of thin steel plate and might go the same way. It should take paint better than brass.
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Post by Roger on Nov 18, 2018 21:01:02 GMT
Hi Roger - I have been so absorbed with my works plates that I have not been following you very closely, but as ever a joy to behold how you set things up. Most people would have built three models in the time you spend, but what a difference! You will find it hard to get it dirty on the track! I like the use of thin steel plate and might go the same way. It should take paint better than brass. Hi Ed, Those works plates are superb, and the time well spent not only for a great result, but also in the learning process which you'll re-use again and again. I suppose it does take a fair bit of time to do things like those bushes, but I wan't it to be a robust and practical locomotive that will survive being taken apart and put back together without any stripped threads. I could have just tapped the sheet, but it's not really man enough in my opinion, even though it's a lot more durable than Brass. It's not only the ease of painting that I like about Steel Sheet, it doesn't pick up dents and scratches like Brass is wont to do. I'm pleased I've chosen to go down that road, I'd certainly do it that way again. |
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Post by David on Nov 18, 2018 21:24:06 GMT
Beautiful work Roger, and thanks for giving the cutting details on the backhead cuts. I hope my cladding is 1/2 as good as yours when I get around to it.
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Post by silverfox on Nov 18, 2018 21:39:39 GMT
Roger
You are making me wish i had never got into this game!!
As regards the brick arch, has anyone thought of those brickplayer bricks of long ago and building a proper one? OR forming one out of vermiculite or similar?
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Post by Deleted on Nov 18, 2018 22:02:03 GMT
Roger You are making me wish i had never got into this game!! As regards the brick arch, has anyone thought of those brickplayer bricks of long ago and building a proper one? OR forming one out of vermiculite or similar? I looked at it Ron....commercially available bricks are too thick, carving is not a good idea due to the health hazards. I had intended to call one of the brick manufactures who make custom bricks...the arch would have to be shaped before kilning..whether they would do a one-off is the big question?...currently busy machining up some alloy adapter plates for my son's Cossie brakes so not had time... Pete |
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Post by Roger on Nov 18, 2018 22:48:12 GMT
Roger You are making me wish i had never got into this game!! As regards the brick arch, has anyone thought of those brickplayer bricks of long ago and building a proper one? OR forming one out of vermiculite or similar? I wonder what I've got into sometimes, but I try not to think too much about it and just keep on going. I had to look up vermiculite, I hadn't heard of that one before. I imagine that a ceramic arch is probably not practical in our scales, and to be honest, I can't see any issue with a metal one from the point of view of what it does. Ok, it might not glow and reflect heat as much, but it's a small price to pay for having something that will handle a good clout from a shovel. |
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Post by dhamblin on Nov 19, 2018 7:58:40 GMT
Would it be possible to attach a ceramic plate to the underside of a stainless steel arch? Differing thermal expansion would be the biggest challenge at the interface but not insurmountable.
Regards,
Dan
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Post by Roger on Nov 19, 2018 8:11:33 GMT
Would it be possible to attach a ceramic plate to the underside of a stainless steel arch? Differing thermal expansion would be the biggest challenge at the interface but not insurmountable. Regards, Dan Hi Dan, You certainly could, there's a machinable Ceramic that you could use to bolt a 5mm sheet onto it. Mind you, it would cost about £60 to do that. I'm just not convinced that there would be a noticeable benefit from doing that. I get the impression that the biggest effect is from the redirection of the gasses, not from the radiant properties of the arch. I may be wrong of course! |
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Post by silverfox on Nov 19, 2018 8:43:06 GMT
Roger
sometimes a tongue in cheek remark sets off a real world investigation ( see Peters remarks!!) And if it were possible surely you wouldn't be that cack handed to hit it with a shovel? Me Yes and possibly knock the loso off the track as well. I have always aid that with my luck if it started to rain soup, i would be the one holding a fork
looking forward to seeing the finished article.
In The Rolls Royce club mag, there was a few years ago a series or articles by a chap who rebuilt/refurbished a (iirc) Phantom I engine and chassis, back then i thought it was out of my league with the intricate details, but it had me hooked and is wonderful reading, and there was always the nugget of info that could be applied in our smaller world.
And now i have the pleasure and luck of reading your build. More power to your elbow sir.
Ron
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Post by 92220 on Nov 19, 2018 9:03:56 GMT
I agree with Roger's comment that a brick arch wouldn't provide any advantage from a radiant heat point of view. The fire is radiant and is close to all faces of the firebox. Even if a 'brickarch' is red hot it cannot be any hotter than the fire coals, and it may be just an inch or so closer to the top of the fire box. Is that going to make any difference to the amount of heat that the water absorbs....I doubt it. As Roger says, the main benefit is most likely to be the deflection of hot gasses so that there is a better distribution between the tubes.
Bob.
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Post by silverfox on Nov 19, 2018 9:31:05 GMT
Bob
I think somwhere in the BR locoamns handbook, it give that reason for the brick arch, mainly it is there to get the 'airflow' more even on the tube plate
Now Bulleids thermic syphons.........did they has a brick arch as well?
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Post by GeorgeRay on Nov 19, 2018 18:06:37 GMT
Yes there was a brick arch in Bulleid fire boxes, they were level with the bottom of the syphon. 😀
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Post by Oily Rag on Nov 19, 2018 20:39:01 GMT
Also when a full size loco is going hard, the brick arch (heat reservoir) does assist in warming the air drawn in from open fire door. One does have to fire when the loco is going hard at time and getting it down to the front of a level 8 foot long grate does need an open fire door and a well directed throw.
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Post by Roger on Nov 19, 2018 22:02:39 GMT
This is the supporting piece being attached to the removable section of the backhead, it's just held on with Soft Solder which is plenty strong enough for the purpose...  20181119_183039 by Roger Froud, on Flickr ... and this is the same piece being attached to the main backhead piece. I've used Plumbers flux and laid a cord of thick flux cored solder in the corner of the joint.  20181119_193308 by Roger Froud, on Flickr I've set it at an angle to help the solder to find its way into the corner...  20181119_193447 by Roger Froud, on Flickr ... which ends up like this after gently heating with the blow torch.  20181119_193608 by Roger Froud, on Flickr It's tidied up ok...  20181119_195904 by Roger Froud, on Flickr ... on both sides.  20181119_195957 by Roger Froud, on Flickr The removable piece was slightly bent, so I've carefully straightened that out. Anyway, the side pieces are supported nicely by those shoulder pieces. I need to add some fixing holes in those, but that will have to wait until the infills are attached to the backhead.  20181119_215032 by Roger Froud, on Flickr  20181119_215106 by Roger Froud, on Flickr |
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Post by Deleted on Nov 19, 2018 22:24:00 GMT
excellent....
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Post by simplyloco on Nov 19, 2018 22:38:48 GMT
This is the supporting piece being attached to the removable section of the backhead, it's just held on with Soft Solder which is plenty strong enough for the purpose... 20181119_183039 by Roger Froud, on Flickr What's this 'ere then? |
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