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Post by gingerneer on Sept 24, 2014 9:58:07 GMT
would it be possible just to have a really small nozzle, say .002" and just have a on off valve?
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Post by peterseager on Sept 24, 2014 16:25:02 GMT
An article appeared in ME describing just such a system and it was said to work. It consisted of a pipe from the manifold to the tank behind the buffer beam. The steam was condensed on its way through the pipe. The tank had a needle valve to meter the oil which was lead straight to the cylinders. I tried to make a similar system for my Sinplex, making a needle valve based on Martin Evans Torquay manor designs. It did not work. The oil tank emptied very quickly. My Mk2 design uses a brass rod with a fine spiral cut into it. The rod is inserted into a close fitting body with the normal unions each end. On the bench it performed as required but has yet to be tested on the loco.
Peter
Edit: Have been trying to think how I tested it. I bought some hose fittings to make up a water connection from the water tap but now I remember that I realised that all I had to do, to test it on the bench, was turn the oil tank upside down so that the oil now came out at the bottom and an airline was connected to the water inlet which was now at the top. Simple.
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mbrown
Elder Statesman
Posts: 1,720
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Post by mbrown on Sept 29, 2014 21:03:14 GMT
Having become fed up with oil-spattered overalls, glasses and bystanders with the mechanical lubricator on my 2.5"g Bagnall, I made a single glass hydrostatic system for my L&B "Lyn", using Don Young's design as a guide. Filled with water and a drop or two of glycerine it works superbly - when I took off the valve chest covers, the cylinders were nice and oily but the top of the chimney stays almost dry. For the latest project - 2.5"g North British 0-6-0 narrow gauge tender loco - I made a double glass, again to Don's dimensions, but attempted to make it resemble the original Detroit lubricator. The top valve is the steam supply to the oil tank, the lover valve is the shut off for the oil flow from the tank, and the two vertical valves are the needle control for each glass. I am going to have to fill the glasses through the horizontal top plugs, but having experimented with a small syringe with a short length of flexible plastic tube on the end, it seems feasible. The round "pothole" glasses go right across so there is back light to the glasses. In terms of appearance, I made the dummy filler plug too high up - the scale size driver would find that the top steam valve prevented him filling the lubricator - but nothing's perfect.... To give an idea of the size, the steam valve handle is 0.25" diameter.
Sorry the photo is so small - I haven't quite mastered the art of reducing them to a size the site will accept while keeping them big enough to see.
Malcolm
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Post by Roger on Sept 29, 2014 21:31:07 GMT
I'm curious to know why mechanical lubricators are set up to provide so much oil. Is it because you can't see the output?
About the pictures.... you're not supposed to attach them any more because they eat up too much space. The way to do it is to sign up for a free account with a photo hosting site such as Photobucket or Flickr and then use a link to the photo you want to show. That uses hardly any of the site's resources and you can have as big a picture as you like.
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cotswold
Part of the e-furniture
Still testing the water
Posts: 307
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Post by cotswold on Sept 29, 2014 21:55:06 GMT
My hydrostatic system is a original Don Young and appears to work exactly as the text book says it should. My spare bottle of sight glass has a label (in my own hand writing) that says it is a 50:50 mix of saturated Epsom Salts solution and glycerine. What I cannot remember is where I got that recipe from.
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Post by Deleted on Sept 29, 2014 23:45:51 GMT
Quote}--- "What I cannot remember is where I got that recipe from." ------------------------- Fanny Craddock ??
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Sept 29, 2014 23:53:26 GMT
completely off topic, didnt fanny craddock make some doughnuts on TV and the BBC presenter (or was it Johnnie Craddock) say
"If you try that recipe at home, I hope all your doughnuts turn out like Fanny's"
(please delete if this isnt appropriate!)
cheers, julian
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Post by Deleted on Sept 29, 2014 23:54:10 GMT
I'm curious to know why mechanical lubricators are set up to provide so much oil. Is it because you can't see the output? ----------------usually because you're limited by the length of the arm in most cases.............................................................
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Post by Deleted on Sept 30, 2014 0:06:31 GMT
OK, these should really go in the "Humour" section but I thought you could have first glimpse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> !2 of the best !!>>>>>>>>>>>>>> 1. Ted Walsh - Horse Racing Commentator - 'This is really a lovely horse. I once rode her mother.'
2. New Zealand Rugby Commentator - 'Andrew Mehrtens loves it when Daryl Gibson comes inside of him.'
3.. Pat Glenn, weightlifting commentator - 'And this is Gregoriava from Bulgaria .. I saw her snatch this morning and it was amazing!'
4. Harry Carpenter at the Oxford-Cambridge boat race 1977 - 'Ah, isn't that nice. The wife of the Cambridge President is kissing the Cox of the Oxford crew.'
5. US PGA Commentator - 'One of the reasons Arnie ( Arnold Palmer) is playing so well is that, before each tee shot, his wife takes out his balls and kisses them . Oh my god !! What have I just said??'
6. Carenza Lewis about finding food in the Middle Ages on 'Time Team Live' said: 'You'd eat beaver if you could get it.'
7. A female news anchor who, the day after it was supposed to have snowed and didn't, turned to the weatherman and asked, 'So Bob, where's that eight inches you promised me last night?' Not only did HE have to leave the set, but half the crew did too, because they were laughing so hard!
8. Steve Ryder covering the US Masters: 'Ballesteros felt much better today after a 69 yesterday.'
9. Clair Frisby talking about a jumbo hot dog on 'Look North' said: 'There's nothing like a big hot sausage inside you on a cold night like this. '
10 Mike Hallett discussing missed snooker shots on 'Sky Sports': 'Stephen Hendry jumps on Steve Davis's misses every chance he gets.'
11. Michael Buerk on watching Philippa Forrester cuddle up to a male astronomer for warmth during BBC1's UK eclipse coverage remarked: 'They seem cold out there. They're rubbing each other and he's only come in his shorts.'
12. Ken Brown commentating on golfer Nick Faldo and his caddie Fanny Sunneson lining-up shots at the Scottish Open: 'Some weeks Nick likes to use Fanny; other weeks he prefers to do it by himself.'
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Post by Roger on Sept 30, 2014 7:38:57 GMT
I'm curious to know why mechanical lubricators are set up to provide so much oil. Is it because you can't see the output? ----------------usually because you're limited by the length of the arm in most cases............................................................. Which begs the question, why don't they fit a bypass valve and hydrostatic style sight glass then?
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JDEng
Part of the e-furniture
Posts: 384
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Post by JDEng on Sept 30, 2014 7:57:45 GMT
I'm curious to know why mechanical lubricators are set up to provide so much oil. Is it because you can't see the output? Roger, This isn't a definitive answer, just an opinion for which I'm probably going to get shot down in flames but here goes anyway...... The beauty of a mechanical lubricator is that it will give a definite, measured quantity of oil which relates to the work being done. A hydrostatic/displacement relies on the driver's setting, hence he needs to adjust the flow depending on the speed and the work being done. Even the GWR kings showed an improved performance when fitted with mechanical lubricators according to K J Cook. A full sized Wakefield lubricator has a ratchet with 100 teeth, each stroke catches three and occasionaly four teeth so it is a very fine adjustment. The pumps (from memory - and it is a while since I stripped one down) have a ram which is only about 5/16" or so in diameter, they are all individually adjustable and each pump only supplies one oiling point (usually). Each pump delivers about 2 Fluid Ounces per 100 miles - this is possibly subject to slight variance subject to loco type. They are set at the works and the only adjustment usually involves altering the position of the pin on the driving arm; there are two positions, one for "running-in" and one for normal running. A model mechnical lubricator is a relatively crude affair in comparison. I also suspect that most people are happy if it is delivering oil and prefer too much rather than not enough. Oil around the chimney top proves it's working. Some mechanical lubricators have a glass tube filled with water or glycerine through which the oil drops rise on a wire, a bit like a hydrostatic, which is one way of setting it and proving it's working although I've never seen this on a model. Google "wakefield lubricator" or "silvertown lubricator" and you may find some schematic drawings. Regards, John. Roger, You obviously posted whilst I was writing: you don't want to use a by-pass in a mechanical lubricator because the output into the steam pipes is affected by pressure; the by-pass is not constant enough. Usually each pump is adjusted by altering the length of it's stroke. J.
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Post by Deleted on Sept 30, 2014 7:59:45 GMT
I'm curious to know why mechanical lubricators are set up to provide so much oil. Is it because you can't see the output? ----------------usually because you're limited by the length of the arm in most cases............................................................. ---------------------one way to reduce output could be to fit the internal pumping unit with a smaller bore/piston......but that's clutching at straws I think as they are fairly small to start with...................Yes, I suppose if you set the pump to MAX output then regulate it via a by-pass system, that would work......A sight glass is already a proven item so I can't see any probs. with marrying the two together...................Has anyone on this forum actually done this ??
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Post by Deleted on Sept 30, 2014 8:02:01 GMT
'morning JD
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JDEng
Part of the e-furniture
Posts: 384
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Post by JDEng on Sept 30, 2014 8:05:16 GMT
'Morning Alan, back from my hols now!! J.
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Post by Deleted on Sept 30, 2014 8:12:18 GMT
posts that "cross in the night"----------JD, I see your point about not using a by-pass from a mech. lube. pump........
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Post by Roger on Sept 30, 2014 8:20:43 GMT
All very interesting and informative. I'm not 100% convinced that a bypass arrangement wouldn't work although I hear what you say about pressure variations. Those could be evened out by using a sprung clack valve set a bit like a safety valve so that the pump was always acting against something approaching boiler pressure even when coasting. I feel an experiment coming on...
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Post by andyhigham on Sept 30, 2014 9:17:28 GMT
The mechanical lubricators Fred Dibnah used on his roller and tractor have a sight glass on the feed and a sight glass for the level. The oil runs up a strand of wire
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Post by Deleted on Sept 30, 2014 9:42:29 GMT
I did try fitting a bypass to a mechanical pump some years ago but it didn't really work . The output was all or nothing so I abandoned the idea. I don't think you can beat the Jim Ewins type pump where the ram passes between two O rings and the amount of oil delivered can be varied by altering the distance between the O rings. Probably a bit fiddly to set up in the first place as you have to experiment a bit with the O ring gap but very reliable.
Putting a sight glass on a mechanical could involve some long pipe runs unless you can mount the lubricator under the cab floor. Usually the lubricator is at the front end of the loco so you would need to pipe the output back to the cab and then forward again to the cylinders. That's assuming you want the sight glass in the cab of course.
John
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Post by Roger on Sept 30, 2014 10:39:20 GMT
Hi John, I'm lucky in that I now have a split eccentric that could go an any axle, so fitting it at the rear isn't a problem. I think a bypass would need a very shallow tapered needle valve. Did you have any restriction on the output like I suggested? I can see why it might be uncontrollable if you don't give it something to work against. It might also be necessary to put a similar sprung ball on the bypass return, albeit at a lower pressure to balance things out a bit. I'm sure a balance can be found, after all, it's delivering a solid column of oil to whatever is distributing it. It ought not to be too hard to find something that works.
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steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
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Post by steam4ian on Sept 30, 2014 10:48:31 GMT
One of the problems with the simple mechanical lubricator we use is that every cylinder stroke has to turn the ratchet wheel at least one tooth. Since the ratchet only has a limited number of teeth there are a limited number of strokes per stoke of the lubricator plunger.
A gear drive between the shaft for the ratchet wheel and the shaft driving the plunger could help.
I do recall in central lubrication systems a metering plunger on each feed, the stroke of this plunger had an adjustable limit to regulate how much oil each feed got. 40 years has dimmed my recall.
Ian
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