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Discussion Starter #1
Hi all,
After posting here some months ago , and taking on board some of the comments , I have done a complete re-design of the LBSC's "DOT" that I was building so as to make a proper G1 black five.
After studying Don Young's excellent drawings for his 5" gauge model , looking at hundreds of photographs and spending many hours with the 3D modeling software I think I now have something.
Nothing is left from "DOT" , but a huge amount of experience , and dozens of castings , but hopefully what I have learned will cut the time for the next loco ten-fold.
The only part left for complete design and construction is the boiler , and I decided that I would have a go at a coal-fired version. I must thank Harry Wade for his advice on certain aspects of the design , as I didn't really know how small a furnace would work.
I thought that the process I have used might be interesting for some of you , although the boiler isn't finished yet and proceeds in spurts in between paying jobs.


Actually I am on the third revision now , having had difficulty in producing the thing to accurate dimensions.
The boiler barrel is tapered and I could not get it correct to my satisfaction using a wooden former and I had no suitable material in stock to turn a former from.
Then I looked at an old 3 leg tinsmiths stake that had been lying about for years , one of the arms, or legs, was about the right taper but 1/4" to big on the diameters.
After 10 minutes with the angle grinder and a thin cutting blade I was black from head to toe and had a two leg stake plus a large lump of very nice cast iron.
Do I hear shouts of sacriledge - well needs must etc!





Half an hour later , I have had a good wash and blown the crap out of my nose , now I remember friday nights at my local back in the 60's , most of my mates were apprenticed at Alfred Herberts and after a week of machining cast iron didn't get clean until sunday LOL!
Anyway after some setting up I had the thing between centres in my little Emcomat 7, and with the tailstock set over 3 cuts later I have a perfect tapered boiler former - 1.69°.




It was then just a few minutes and I had a lovely tapered copper tube ready to rivet and silver solder down the seam.





The throat-plate needs to fit snuggly into the tube so I thought I would make a press tool to form the flange !





Today's job is to make a steel former for the throatplate but I am aching a bit so I thought I would write this instead.
During my search for materials I visited a local yard, in a shed I was shown various bar-ends and was quite taken by some 2 3/4" and 2 1/2" bits about 3" long , perfect for punches and dies etc , and the wheel rims for my loco.
As I can't cast iron at present I was planning to make my wheels in brass and fit steel rims.
I got as many as I could carry and gave the guy a fiver.
I set up a piece of the largest diameter and started turning it , boy this is tough stuff.
There was a spec etched on one of the bar ends so I looked it up on the good old net.
Turns out to be M152 - 17% chrome ,nickel moly steel for use in aircraft turbines , now that makes sense as there is a famous turbine factory not 5 miles away.
This is be-eautiful steel ,slow to machine on my small lathe with no coolant and no carbide but the finish is superb , the turning are a pain and with no chip-breaker come of as one mile long piece.
There must be fifty to a hundred pieces or more so if you want some good steel cheap now's your chance.
If you live in the UK of course!
 

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Discussion Starter #2
80 view and no comments ? well never mind , I will thrill you some more with the next days work !
As I said earlier I had already made a couple of hardwood formers for the throat-plate and wasn't happy with the results , so I decided to have another go in steel , and found a nice piece of 1/2" thick flat in my odds box , got a few holes from other uses but useable !





I don't go in big time for marking out , can never find my scriber , get blue everywhere and can't see the lines anyway , so I printed a full sized picture of the job and glued it onto the steel.





I allowed 1/8" around the actual size and centre popped every 1/4" along the outer line.
Using a drill 10 thou under 1/4" I chain-drilled the plate.
After 4 hours of drilling , sawing and judicious use of my favourite precision tool, the trusty 4" angle grinder , followed by a bit of filing and polishing and I had the throat-plate former, and very sore hands.





To make sure that the boiler barrel flange is located true , and to hold the copper whilst bashing I turned up a piece of the previously mentioned steel bar,
I digress here , I have quite a large quantity of throw-away tool tips but only a small boring-bar holder , a neighbour "borrowed" me a holder from work and the turning was definitely easier this time round , after I had re-threaded my tool-post as I stripped one of the clamping screws tightening the bloody thing!





So, previously stamped blank annealed , clamped in place , two minutes with the rubber mallet , and a few taps with a planishing hammer , doubles as a ball-pein, later.





and here's the plate ready for pickling !





yes I have cheated , I had trimmed off the surplus before taking the photos but I am sure you get the picture !
my old vice is looking sad , but boy has it done some work in its life ! it's solid steel, I have broken several cast-iron vices in the past but I can't break this bugger even with a 4 foot scaffold tube as a lever. It might get a lick of paint this summer , or should I paint the kitchen , the spare-room , the living-room
 

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abby,

Very impressed with the craftmanship and much appreciate the effort you have put into teaching about what you're doing. Thank you.

Steve
 

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Abby

Excellent work. I found you photos and explanations most interesting. Its not often we find this quality of work in Gauge One.
My only concern is that coal firing in a narrow firebox in this scale is going to be tough. That is not to say it can't be done but it's not easy.

Anyway, keep up the good work!
 

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80 views and no comments?


Abby,
Most of them don't know what to say because this rather complex work is foreign to the present state of mainstream US Ga1. This is model engineering in it's essential sense.
 

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Posted By Old Boy on 03/13/2009 3:22 PM
Most of them don't know what to say because this rather complex work is foreign to the present state of mainstream US Ga1. This is model engineering in it's essential sense.



Old Boy, all the other coments were positive as it is nice work. Is it always raining where you are?
 

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Beautifull work!! Sure wish I had an teacher near me as I would love to learn how to do this and build my own coal fired engine. Cant wait for more progress pics. Mike
 

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Abby, Please keep the photographs coming. I am contemplating a boiler project am you are providing inspiration as wall as education. Beautiful work!
 

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Abby
Learning is key to making the hobby grow and your post of the process for making the boiler teaches a lot on how to overcome via innovation to make it happen.
 

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Discussion Starter #11
Thanks to all for the enthusiasm , it makes it worth while , Tac I am not a member of G1MRA , I did try to join a couple of times but got no reply so I don't think they want me , AsterUK I too am not sure about the coal firing so I am making a spirit fired version along side just to hedge my bet.
 

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Discussion Starter #12
There is no doubt in my mind , that after the lathe and drilling machine a press is the most useful tool to have in a small workshop , here in the UK they are becoming scarce , the demise of our industrial base has seen hundreds of thousands go to the scrap yard. Most likely returning home resurrected as a chinese manufactured machine tool.





This is my fly, or hand press , it is rated as a no.3 and has a force of about 1 1/2 tons but they were made from very small to very large and all look similar.
The power is supplied by swinging the handle and thousands of women were employed in Birmingham making every imaginable item from jewelry to armaments.
I use my press for lots of different jobs besides punching , and I have made a tool for quartering wheels whilst pressing them onto axles , broaches for making square or hexagon holes and jigs for bending sheet metal. Because the power is supplied by hand the fly press is slow compared to a power press , but tooling can be very simple and cheap to make.
Because some of you expressed interest I thought some very basic press tool instruction might go down well.
Although all of the parts for this boiler could be made by hammering the copper on wooden formers I want to make a few so that I can try out different flue arrangements and spirit firing and also I just love making tools.
The next part of the boiler is the end plate , this is just a disc with a flanged edge , the flange provides a good contact area for silver soldering and locates the end plate securely into the boiler barrel. I prefer to use a flange wherever two pieces of copper join and would never use a butt joint . As for grinding or filing off the surplus copper , certainly not , no qualified boiler inspector would pass a boiler treated in such a fashion.
This end plate tool is designed to do all the required operations with minimum tool changes and the die - female part - fits into the centre of the die used for the throat-plate,





The die has two internal diameters , the smaller being the same as the end of the boiler with a generous lip radius to help the metal form gently , and the larger being 1/4" bigger to provide metal for the flange.
I have used good quality steel for both the punch and the die , as a general rule if the hole is important then harden the die and leave the punch soft , if you are only interested in the slug of metal then the other way round. Punching tools should have around 1 thou of clearance.
The punch has two external diameters , one end has a clearance fit in the large die diameter and the other end is smaller than the small die diameter by twice the copper gauge and is radiused as per the metal gauge.
The punch is threaded 1/2" whit right through end to end and is screwed onto a threaded holder in the press ram.
All the machining operations are turning or boring in the lathe so I am sure you don't need pictures!
Copper sheet positioned under the punch.





and pressed , leaving metal slug in the top of the die.





punch unscrewed and reversed





pressure applied to the blank , see it forming !





lets make another one





and heres the result straight off the press so to speak !





fitted into the boiler barrel





just a slight gap where the tube seam touches





this can be closed before silver soldering by gently tapping with a piece of suitably shaped brass or wood
I'll just see how it looks on "DOT"







Just need the holes for the flues and blower pipe flange but got to go play ball now !


 

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That is really cool stuff! I certainly admire your tool making abilities. I'm sure I'll never build a boiler like that but I love seeing what goes into it.
 

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Abby,
The press looks custom made for just this work, what a lucky find. When it comes to hole drilling save yourself a few tears, . . . don't reach for the twist drills, get yourself a "Uni-bit" or whatever your local equivalent is. These makes short, neat work of flue and bushing holes in thinnish copper.
 

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I hate to be redundant, but this is a fascinating thread. Thanks for taking the time to share with us.

We will be anticipating your updates!
Matt
 

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Discussion Starter #17
This boiler , is for a Stanier class 5 locomotive , but no-doubt people with more knowledge than me will say "it will also fit a " , and I am sure that would be true with very little alteration .
It is largely in fine scale , but the wheels are G1 standard scale , as I believe this has more wide-spread usage in garden railways
It is part of a complete loco build project from scratch. Although I am lucky enough to earn my somewhat meagre living in the model engineering field it is by necessity a "part time" project and I expect it to take the best part of a year to complete.
Any comments on aspects of design will be appreciated , I class myself as a noob to model railways.
Then I will need rolling-stock and a railway to run it all on.
This first version of the boiler is to experiment with coal-firing , many people say that this is difficult in small furnaces , I don't know , so I will also make a spirit fired version just in case.
Much of the design is scaled from full-size and ideas have been taken from other well respected designers of larger scale models , but much will be unique , I believe , especially the extensive use of lost-wax castings produced from rapid-prototyped patterns.
As well as being an exercise in model engineering , it is also an exercise in 2D/3D cad , production methods and tooling.
This is the computers idea of what it will look like !





and the fit between the frames.







Looking into the cab





and from the front





more later.
 

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Abby,
Your project is truly a work of art! I'm sure Curly would be proud of your effort! Your presentation and pictures are first rate and done in an engaging manner. I look forward to your next installment.
 

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Abby,
I think I finally figured out that the press in the photos is what is called a screw press over here. I am guessing that there is a screw with a hand wheel and a ball weight. The operating handle can be seen in the photo as a vertical rod. These are scarce in the US also and the ones on ebay are not cheep.

I do a bit of bronze casting in my shop and I have been following this thread with a lot of interest.
Dan
 

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Discussion Starter #20
Sorry Dan , I should have called it a screw-press in the first place , I have been guilty of dispatching hundreds to the iron foundries in the past , along with small milling machines and lathes but fortunately I have a far-seeing buddy who has saved 20 or so various sized screw-presses , "well they don't eat anything" he says !
I wish you could see his yard , it's actually a boat yard with a 80 foot dry-dock for building what we call narrow boats.
These boats or barges carried the heavy trade on a nation-wide system of canals before the railways came , but were finally finished by the big freeze in the 1960's.
However recent years have seen a massive increase in pleasure traffic and much money has been re-invested to repair and beatify the canals.
It is claimed that Birmingham has more canals than Venice and many of the warehouses and factories that lined the banks have been torn down and replaced with modern buildings and plazas that are breath-takingingly beautiful.
Anyway his yard is like a museum of scrapped items from old single cylinder petrol engines to complete cast-iron buildings , there is even an original Thomas Crapper water closet LOL !
Back to the subject , I suppose an hydraulic garage press or even a large vise could be used to the same effect, but provision would need to be made to keep the parts aligned , like in this tool for pressing wheels onto axles and quartering at one go.








This does mean that the tools are a bit more complex and take more time to make.
I found sand casting to be a bit of a black art , something would work one day and fail the next , so I had a dabble with lost-wax casting and after developing some equipment found that I could produce castings with a 95% certainty that they would be sound. The actual moulding and casting is very easy and reliable , the real job is producing the wax patterns - one for every casting - accurately and most importantly cheaply and I use many methods including high pressure injection into fully machined dies or just pouring into rubber moulds.
Much of this loco project uses lost-wax parts requiring very little finishing and the minimum of machining , although the parts are predominantly in gun-metal (red-brass) I have also used nickel-silver where a steel or cast-iron finished look is required.
 
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