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Post by modeng2000 on Feb 10, 2008 22:38:58 GMT
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paul
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Posts: 8
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Post by paul on Feb 11, 2008 8:43:50 GMT
Woo, those look mighty neat! Is that ring solid and what's it for?
I tidied up the edges on mine by taking a tiny cut on the lathe. It's a strange material!
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Post by modeng2000 on Feb 11, 2008 14:43:40 GMT
Hi Paul, Yes soft copper is not the easiest of metals to machine. I don't know if it is in the script but I used the lathe to tidy up the rims. hardly anything to come off. The solid ring sits at the bottom of the boiler between the two large tubes and forms the base, possibly called a 'mud ring' I think. I formed it from 1/4" sq copper bar using my bending rolls. I had to anneal the bar about 5 times before I could close the circle.
Things have moved on now and I have made holes for the bushes but not the bushes themselves, next job. Another picture when there is more to show.
John
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abby
Statesman
Posts: 925
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Post by abby on Feb 11, 2008 17:27:56 GMT
Looking good , is it also called a foundation ring ? what is the diameter of your boiler tube ?
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Post by havoc on Feb 11, 2008 18:35:28 GMT
Looks mighty strong I must say. But beautiful pieces of copper. Sure this is gauge 1?
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Post by modeng2000 on Feb 12, 2008 10:19:11 GMT
Here is the latest picture of the boiler components. The rule might help to give some idea of scale. The large tube is 66mm dia. The copper wires are used to hold the parts in the right places for hard soldering. The loco is for a narrow gauge G scale Garden layout so no doubt it might look a bit on the large size. Now comes the hot bit! John
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Post by modeng2000 on Feb 12, 2008 17:14:30 GMT
Here are two views of the boiler, during construction and then finished. Had to have two goes at the foundation ring but it looks OK now. Next the pressure test but that will have to wait for another day. John
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Post by havoc on Feb 12, 2008 18:21:51 GMT
Beautiful piece of work.
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paul
Member
Posts: 8
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Post by paul on Feb 12, 2008 20:44:27 GMT
Nice!
John, how did you get on with drilling those holes for the diagonal tubes? Nearly all the holes I've ever drilled in copper have either come out off-round or slightly out of position, I'd hate to think how a diagonal would come out for me!
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Post by modeng2000 on Feb 12, 2008 21:28:33 GMT
Thanks Havoc, I'm no expert in silver soldering but do my best. As far as I can tell, the joints are OK but should there be a problem I'm shure it can be fixed. I was very careful with the inner joints in particular as a leak there would be more challenging to fix.
As to drilling those oval holes Paul, they started out as round ones and got converted with the use of a round file. Any ragged fit just provided the space for the silver solder to penetrate the joint.
Using the lengths of about 1mm dia copper wire to position the parts before soldering was a complete success, no worries about movement.
Thinking about the threads in the bushes I decided to stay with ME threads as they seem to be most commonly used. I do prefer metric but not if it makes things difficult for me!
John
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paul
Member
Posts: 8
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Post by paul on Feb 12, 2008 21:51:10 GMT
As to drilling those oval holes Paul, they started out as round ones and got converted with the use of a round file. Any ragged fit just provided the space for the silver solder to penetrate the joint. John Ah, that had crossed my mind but I thought there'd be a 'proper' way to do it The copper wire is a good idea; I've seen rivets used for the same purpose but your wires are neater. What sort of stand is the boiler going to be on and will you be using a spirit burner?
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Post by modeng2000 on Feb 13, 2008 7:30:34 GMT
The base of the boiler has a skirt fitted underneath that is the diameter of the firebox opening and this surrounds the gas burner. There will be three or four fixing tabs secured to the foundation ring to hold the boiler. As there are no rivets in this design it seemed a good idea to use something like the wire because it can be filed back to the boiler shell leaving nothing poking out.
Another first on this job was the cyclone burner I used. My other gas torch burners are the usual type and while they work OK this cyclone burner did seem to heat the job more satisfactorily. It is said that the rotating flame tends to surround the work and it does seem to get more heat into the job but the main reason for using one is that the air for the burner is taken in near the handle not the flame and so there is no problem with the torch burning properly when used in a corner of the braising hearth.
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Post by mackintosh on Feb 13, 2008 19:47:17 GMT
John very neat sound job well done Bob
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Post by havoc on Feb 13, 2008 20:32:03 GMT
Well, if you want to do it proper.... then you could do the following: you take a piece of wood larger than your boiler barrel. Imagine that you drill out a hole in it to hold your barrel. Now, drill through the wood so that (if your boiler would have been in it) you would drill the holes for your tubes. Then drill the hole where the boiler needs to be. Now fit the boiler barrel into the woodblock and secure it. Using the holes you drilled as a guide, drill the holes for the tubes. Best would be if you kept a core of wood in your barrel as well.
Now, filing those holes to shape looks good, doesn't it?
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paul
Member
Posts: 8
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Post by paul on Feb 13, 2008 21:32:06 GMT
OK Havoc I see.... a 'copper sandwich'!
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Post by modeng2000 on Feb 22, 2008 22:22:34 GMT
Here is a sleeve type clack valve for in-line fitting instead of fixing directly to the boiler. The screw threads are all 1/4" x 40 and the sleeve is 2mm internal. Hope it may be of interest, John
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Post by havoc on Feb 23, 2008 10:25:55 GMT
Very good idea! I saved that one for reference. Looks a lot simpler to make than the usual designs.
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abby
Statesman
Posts: 925
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Post by abby on Feb 23, 2008 11:27:33 GMT
Is this what our American cousins call a "goodall" valve ?
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Post by modeng2000 on Feb 23, 2008 15:41:20 GMT
I have found a picture of a Goodall valve It seems that the filling tube is pushed into the top of this valve whereas my sleeve valve is meant to be in-line with the filling connection away from the boiler and hot bits. John
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Post by mackintosh on Feb 23, 2008 19:50:16 GMT
John Just a thought we use silicone O rings in the cylinder and they stand the heat and I assume that is silicone tube, so that should also stand the heat. Or am I way off? Bob
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