44767
Statesman
Posts: 529
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Post by 44767 on Jan 2, 2022 13:58:08 GMT
Well done Bob! That is quite a bit of work to finish the valve. For those wanting to make their own, I may be able to supply the valve as part of the kit of castings etc.
Mike
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Post by 92220 on Jan 2, 2022 19:22:28 GMT
Hi Mike.
That would be a great help for anyone who wants a set of castings. The stainless steel valve is the hardest part of getting the valve to work properly. When finished, it is a perfect scale model of the fullsize valve. A lovely addition to any loco. Well done for all the work you put in to get the castings right.
Bob.
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Post by 92220 on Jan 30, 2022 9:31:34 GMT
I'm still working on the pressings for the various clothing corner moldings. I hope to have something to show in the near future. Some time ago, Adam Cro sent me a set of castings to make up the fully working, superscale, manifold, for the boiler. This is a fully operational manifold that is a miniature of the fullsize, and lovely quality castings. The first job was to make up a jig to hold the casting safely, for machining the mounting boss in the 4-jaw, and threading it. Next, I machined all the accessible mounting faces, I could, while it was still mounted on the jig. A piece of brass bar was then faced off, and drilled and tapped, for the manifold to be screwed in tightly. This enabled the rest of the mounting faces to be machined. While facing off the mounting flanges, all the tappings were drilled out and tapped. The round, brass, mounting bar, was held in the side of the vice, on the mill, with a small vee-block to keep it square and in line with the mill table, and with a solid spacer under the one end to prevent the manifold trying to rotate and come un-done, in the holding jig. Unfortunately I didn’t take many photos while machining the manifold, but I’ve attached all I did take. The manifold casting fitted to it’s machining jig, held in the 4-jaw. The mounting boss was turned to size and threaded 3/8” x 32 M.E. Img_4315 by Robert Shephard, on Flickr A piece of 5/8” dia brass bar was drilled and tapped 3/8” x 32 with the first 2 threads turned out, to ensure the manifold would screw uptight to the shoulder and the manifold was screwed in tight. This was held in a Vee-block to ensure the threaded boss was dead parallel to the mill table. The various shoulders for each threaded hole were then carefully machined with a new, carbide, 8mm endmill. Img_4325 by Robert Shephard, on Flickr Img_4328 by Robert Shephard, on Flickr Img_4326 by Robert Shephard, on Flickr The next job was to machine up the bits for the stop valve. Img_4350 by Robert Shephard, on Flickr The thread in the stop valve is 1/8” x 80 tpi. I got a series of these very fine taps and dies, from Tracy Tools. I think they still have a few in stock, but only oddments. This is machining the hexagon on the stop valve valve unit, taking great care not to make too heavy a cut that the screw thread unscrewed. Img_4331 by Robert Shephard, on Flickr This is the finished stop valve fitted to the manifold. Finished Stop Valve by Robert Shephard, on Flickr The next part to make is the whistle. This is a dummy but the whistle valve is operational in so far as it lets a jet of steam come from the dummy whistle when the main loco whistle is sounded. I have yet to decide where the operational whistle is going to fit. It has to be somewhere that under normal viewing, cannot be seen. The tiny whistle valve casting has nowhere that can be held normally to machine it, so a holding jig had to be made. This is it with the valve casting shown fitted in place after the flange was machined and the mounting holes drilled for 12 BA hex head screws. The screws were made up by machining them from 0.078” A/F mild steel hex rod, to give a scale head size. Umnfortunately I didn’t take any photos of making these. Img_4352 by Robert Shephard, on Flickr This is the holding jig for the whistle valve: Img_4355 by Robert Shephard, on Flickr This was how the whistle valve was set up, and drilled, for the stainless steel valve rod. It’s square mounting flange was used to clamp it upright onto the end of a piece of aluminium bar that had the end face machined vertical. Img_4361 by Robert Shephard, on Flickr This is tapping the whistle valve for the dummy whistle. Img_4364 by Robert Shephard, on Flickr This is using a scalpel blade to part off PTFE sealing washers for the various steam joints for the whistle valve. Img_4370 by Robert Shephard, on Flickr This is machining the whistle valve operating lever. Img_4378 by Robert Shephard, on Flickr This is the whistle operating lever after machining. It just needs tidying up, to fit. IMG_4380 by Robert Shephard, on Flickr Thyis is the finished manifold ready to fit to the bopiler. Img_4381 by Robert Shephard, on Flickr Img_4382 by Robert Shephard, on Flickr Img_4383 by Robert Shephard, on Flickr Img_4384 by Robert Shephard, on Flickr Bob. EDIT. I should have said to take no notice of the large lump below the manifold, in these last few photos. It is not part of the manifold. It is a tapped lump of brass that the manifold is screwed into so that it stands up off the bench/shelf until fitted to the boiler, and doesn't get damaged where the whistle operating lever is at an angle downwards. Bob.
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44767
Statesman
Posts: 529
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Post by 44767 on Jan 30, 2022 10:05:14 GMT
Very nice work, as usual, Bob. 90% of machining is is the set-ups!
Mike
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Post by Roger on Jan 30, 2022 10:18:34 GMT
lovely work as always Bob, that looks superb. I really enjoy seeing your tooling methods.
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Jan 30, 2022 18:16:42 GMT
Yes Bob, fantastic work on that manifold.....must have taken you a good few hours!
I know that you are following “Works Drawings” wherever possible for this model, but are you adding the additional bits here and there that the loco carries nowadays in preservation, or modelling it as it was built?
Regards Don
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Post by Deleted on Jan 30, 2022 18:39:20 GMT
Great work Bob, truly superb...
Pete
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Post by 92220 on Jan 30, 2022 18:47:23 GMT
Thanks guys. I'm close to finishing the male part of the press tool for the clothing throatplate moulding. I'll write up a description of that shortly, with photos.
Bob.
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Post by 92220 on Jan 30, 2022 18:51:30 GMT
Hi Don.
I'm building as is now. That is the only way to make sure it is correct as there have been additions and upgrades during it's short life. For instance, when first built, Evening Star had 2 small footsteps below the smokebox door. Very early on, this was changed to the single triangular step as fitted now. The one thing I'm not copying, is the bent front step on the lefthand side!!
Bob.
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Jan 30, 2022 19:29:00 GMT
Thanks Bob, I was wondering because with regard to the manifold on “Evening Star” nowadays, I believe that the takeoff from the very right hand end of the manifold is additionally used for the carriage warming supply, which obviously was not the case in the 1960’s! At that time it only had a smaller pipe just feeding the steam lance and cylinder lubricator warming coil.
Regards Don
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Post by 92220 on Jan 30, 2022 23:03:57 GMT
Hi Don.
Yes that is right. I had already found that because you sent be a photo that shows the pipe going into the cab, and my internal cab photos show the valve on the other end. That is why the manifold is not blanked off there....so getting that right is thanks to your help! I now have photos that show all the piping from the manifold, together with all drawings necessary to work out where those pipes go.
Bob.
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Post by mugbuilder on Jan 31, 2022 1:46:22 GMT
What a fabulous fitting. You must have endless patience. Barry
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