jma1009
Elder Statesman
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Post by jma1009 on Sept 20, 2020 10:05:05 GMT
I seem to recall (though haven't checked) that in ME in 1967 Brian Lee published indicator tests on a Juliet. Don't ask me which form of Juliet was involved.
The indicator tests showed a very high amount of compression - exhaust steam not fully released and being compressed by the piston whilst the valve was closed on the return stroke.
You ought to aim to get the steam into the cylinder at the right time, sharply, and out again quickly once expanded. Good valve gear design, accurate manufacture, and good valve gear setting, combined with proper and adequate ports and passages (and pipework) will make all the difference to performance on the track. And like Ross, I've mucked about with these things and know the before and after results.
Why spend years making something, at some considerable expense, only to end up with constipated cylinders?
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
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Juliet
Sept 20, 2020 10:39:05 GMT
Post by smallbrother on Sept 20, 2020 10:39:05 GMT
I should add that I managed to nick one of the port edges with the drill bit as it broke through the steam passageway.
Too heavy handed. Lesson learned I hope.
Pete.
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mbrown
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Post by mbrown on Sept 20, 2020 11:04:11 GMT
Well remembered Julian. It was the Baker valve gear Juliet. I think it was a little later than 1967 as I only took ME from 1968 and am sure I have the article somewhere.
Interesting that in over 50 subsequent years, I haven't seen any further indicator experiments in our sizes, though I stand to be corrected.
Malcolm
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Post by ettingtonliam on Sept 20, 2020 14:23:39 GMT
Yes Julian, you are right in what you say, but theres been hundreds of Juliets and Rob Roys built over the years, many as a first loco (my Juliet was), some good, some bad, some, like mine, indifferent. Virtually all of them, however bad, will enable the builder to achieve his hearts desire at the time, which is to chug round a track behind his own creation. It doesn't matter to him (anyway it didn't to me) particularly, that it could do it using less water, less fuel, be more lively, notch up better (indeed, if at all). That all comes later. IMHO. As Phil will probably find.
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smallbrother
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Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Sept 26, 2020 12:28:37 GMT
Just completed all the angled holes. Not sorry to see the end of them on these cylinders. Pete.
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timb
Statesman
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Juliet
Sept 26, 2020 14:04:57 GMT
Post by timb on Sept 26, 2020 14:04:57 GMT
Looking good Pete, well done. Its definitely nerve racking with all the work that has already gone into the cylinders to get them to this point.
Tim
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smallbrother
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Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Sept 26, 2020 15:01:20 GMT
Post by smallbrother on Sept 26, 2020 15:01:20 GMT
Looking good Pete, well done. Its definitely nerve racking with all the work that has already gone into the cylinders to get them to this point. Tim Couldn't agree more! Pete.
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Post by delaplume on Sept 27, 2020 21:24:29 GMT
Congrats Pete----attention to detail at this point in the proceedings pays dividends later on........Don't forget to machine out a small recess where those port drillings meet the intrusion of the cylinder covers.....
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smallbrother
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Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Sept 28, 2020 11:22:33 GMT
Post by smallbrother on Sept 28, 2020 11:22:33 GMT
Congrats Pete----attention to detail at this point in the proceedings pays dividends later on........Don't forget to machine out a small recess where those port drillings meet the intrusion of the cylinder covers..... Looking more carefully at the drawing (obviously missed it before!) there appears to be a recess all around each end of the bore. Would have been so easy to take that out at the boring stage. Yet another lesson learned the hard way! Just finished drilling pilot holes in the cylinder flanges and same in the frames. I will finish the exhaust ports off before I begin the steam chests. I would like to think I have passed the mega-cock-up stage with the cylinders but you never know! Pete.
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Post by ettingtonliam on Sept 28, 2020 11:37:45 GMT
That recess, if its all the way round, would be so that its possible to rebore the cylinders when they wear, without scrapping the covers. I didn't know LBSC was so sophisticated! No matter if you haven't done it, hundreds of locos don't. As Alan says, you do need a recess just where the drillings break into the cylinder, either that or machine away the cover spigot over the area of the drillings. I think LBSC just used to specify filing a little flat in the edge of the bore.
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smallbrother
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Posts: 2,269
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Post by smallbrother on Sept 28, 2020 11:56:32 GMT
Here's a photo. I will try and poste a photo of even the very basic steps from now on. Hopefully this will encourage more people with low skills like me to give it a go. Pete.
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timb
Statesman
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Post by timb on Sept 28, 2020 14:54:17 GMT
Don't make little of your achievements Pete, as I have said before if you can put on coupling rods and the wheels go round without binding then you have done better than most that have a go!
You should be very proud of your work, I think it looks great and am looking forward to seeing your loco progress.
Well done Sir!!
Tim
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Post by Deleted on Sept 28, 2020 17:18:00 GMT
I agree with Tim, there's nothing 'low' about your work Pete. Not everyone can build a live steam locomotive...you are very much in the minority sir. Hell, how many people both male and female out there can't do the most simple of daily tasks...for example, how many struggle to put on a mask?.... Pete
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stevep
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Posts: 1,070
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Post by stevep on Sept 28, 2020 17:18:54 GMT
I agree with Tim, there's nothing 'low' about your work Pete. Not everyone can build a live steam locomotive...you are very much in the minority sir. Hell, how many people both male and female out there can't do the most simple of daily tasks...for example, how many struggle to put on a mask?.... Pete ...or understand that it's meant to cover your nose too!
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smallbrother
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Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Sept 28, 2020 17:54:38 GMT
Yeh but we are engineers here, official or amateur! But thanks for kind comments.
To think our forbears produced the real-size monsters in great numbers with less than ideal equipment!
Anyway, I hope anyone reading this, who thinks they would like a go, but has never done anything like it, feels a bit more willing to give it a try.
Pete.
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Juliet
Sept 28, 2020 18:42:55 GMT
Post by delaplume on Sept 28, 2020 18:42:55 GMT
This says it all.....and in a style that we can all relate to ( I hope !! )------------> youtu.be/X8fCXNTCWig
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Sept 29, 2020 7:46:53 GMT
Post by smallbrother on Sept 29, 2020 7:46:53 GMT
This says it all.....and in a style that we can all relate to ( I hope !! )------------> youtu.be/X8fCXNTCWigMy late Mother's favourite artiste. Pete.
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Post by delaplume on Sept 29, 2020 9:45:42 GMT
This says it all.....and in a style that we can all relate to ( I hope !! )------------> youtu.be/X8fCXNTCWigMy late Mother's favourite artiste. Pete. There you are then Peter........ an omen of good fortune !!.........Crack-on Moriarty, crack-on !!
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Juliet
Sept 30, 2020 7:49:23 GMT
Post by smallbrother on Sept 30, 2020 7:49:23 GMT
It was bound to happen. I walked into this with eyes wide open and could shoot myself. I claim cock-up of the month. I have positioned the exhaust hole way too close to the edge of the flange. It isn't even the full diameter yet, being 7mm and needs to be 7.1mm. I have some 3mm thick copper and can screw some of this to the boss to make the whole thing thicker. Is there a better solution? Pete.
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mbrown
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Post by mbrown on Sept 30, 2020 8:12:15 GMT
We all do it sometime, Pete.
If I remember Juliet correctly, nothing would be fouled by extending the flange upward a bit. I would be inclined to get a strip of brass about 1/8" think and the same width as the flange, tin it with soft solder, and screw it to the flange to extend it upwards. Then heat the whole lot until the solder fuses. Run a file over the face that mates with the frame so that it is flush with the milled flange on the cylinder. Then you can open out and tap the hole. Brass will take a thread much more easily than copper As it is not under any stress, soft solder to seal the joint will be quite adequate. If you wanted to be pedantic about it, you could solder a similar strip to the other cylinder so that they match - but that would just be cosmetic.
The thing I am more worried about is whether the exhaust holes in the two cylinders will now line up so that you will be able to screw in the exhaust connections in line. If not, you may have to bite the bullet and tap and plug the hole that is in the wrong place (soft solder sealing should be OK) and re-drill in the correct position
Good luck
Malcolm
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