Finescale - of a sort?!
- Thread starter Peter Insole
- Start date
simond
Western Thunderer
This doesn't really tell us what happens to the wall thickness as the tube is swaged, but given that it starts at 3.5" and "150 wall" (I assume thou) and ends up at 5/8" diameter, simple scaling would give a wall of 27 thou which might not be a million miles out.
I quite like the extrusion process!
you'll have to go to YouTube to watch it
I quite like the extrusion process!
you'll have to go to YouTube to watch it
Last edited:
Peter Insole
Western Thunderer
Thanks to all for the very interesting replies!
I should have explained that the "trick" for straightening after unrolling was simply to crush flat both ends of the tube, firmly grip one end in a heavy bench vice and a large mole wrench at right angles to the pipe at the other... then give the inside (from the vice end) face of the wrench a really good whack with a hammer! Apparently it appears to work like magic every time?!
Admittedly, having only ordered a one meter length, I've not got an awful lot of waste material to play with - which is another reason for deciding to just do the best I can with what I have!
(part of image taken from an unknown source, and shown here for illustrative purposes only)
The above picture was chosen for scaling the pipe run, as it is probably a finer example of the Horwich coppersmith's work than all the other seven locomotives put together. Most reveal quite a variety manufactured bends - and an awful lot more unintended ones too - so I do have a little leeway!
Fortunately, as you can (sorry, just about!) see in the drawing below, the radii at both ends are reasonably generous - all that is except the bottom curve on the left hand pipe (shown here) - just at the point where it enters the front face of the well tank beneath the running plate!
I can use a tool for that bottom one, but I do quite like the idea of using fine, dry sand inside the pipe to prevent the larger bends from squashing when worked by hand. According to a contemporary published article, the Beyer Peacock specifications called for the use of resin (although I don't recall any mention of what type) to achieve the same end.
There will be a bit of fun, and probably a fair quantity of crisp language to come later, down in the railway workshops here anyway!
Pete.
I should have explained that the "trick" for straightening after unrolling was simply to crush flat both ends of the tube, firmly grip one end in a heavy bench vice and a large mole wrench at right angles to the pipe at the other... then give the inside (from the vice end) face of the wrench a really good whack with a hammer! Apparently it appears to work like magic every time?!
Admittedly, having only ordered a one meter length, I've not got an awful lot of waste material to play with - which is another reason for deciding to just do the best I can with what I have!
(part of image taken from an unknown source, and shown here for illustrative purposes only)
The above picture was chosen for scaling the pipe run, as it is probably a finer example of the Horwich coppersmith's work than all the other seven locomotives put together. Most reveal quite a variety manufactured bends - and an awful lot more unintended ones too - so I do have a little leeway!
Fortunately, as you can (sorry, just about!) see in the drawing below, the radii at both ends are reasonably generous - all that is except the bottom curve on the left hand pipe (shown here) - just at the point where it enters the front face of the well tank beneath the running plate!
I can use a tool for that bottom one, but I do quite like the idea of using fine, dry sand inside the pipe to prevent the larger bends from squashing when worked by hand. According to a contemporary published article, the Beyer Peacock specifications called for the use of resin (although I don't recall any mention of what type) to achieve the same end.
There will be a bit of fun, and probably a fair quantity of crisp language to come later, down in the railway workshops here anyway!
Pete.
Peter Insole
Western Thunderer
Thank you for the tip Fitzroy, it got me on a fascinating search. I think I will pass on it though, as it would appear to be distinctly toxic stuff - and I have to be careful with my own particular health problems nowadays!
I found several references to using salt as an alternative to dry sand, and as that certainly seems to be a much more accessible product - a clandestine raid on the kitchen cupboard is imminent!
Pete.
I found several references to using salt as an alternative to dry sand, and as that certainly seems to be a much more accessible product - a clandestine raid on the kitchen cupboard is imminent!
Pete.
Heather Kay
Western Thunderer
Would beeswax work? It’s easy to melt, for both getting into the pipe and back out.
Peter Insole
Western Thunderer
Thank you Simon for trying to save me from my wayward tendencies.
A domestic crime may have been avoided anyway, as I have just been informed that one of my sons already has some sand... albeit dyed in a delightfully fetching purple shade!
Thank you too Heather! I wouldn't be at all surprised if we have some of that secreted away around here as well! There is quite a lot of "crafty" stuff (arty of course!) going on in our various family households these days.
Pete.
A domestic crime may have been avoided anyway, as I have just been informed that one of my sons already has some sand... albeit dyed in a delightfully fetching purple shade!
Thank you too Heather! I wouldn't be at all surprised if we have some of that secreted away around here as well! There is quite a lot of "crafty" stuff (arty of course!) going on in our various family households these days.
Pete.
Peter Insole
Western Thunderer
I have got the fine sand ready now for the big bending session, but fancied sorting out the materials for the flange joints first. As it happens, I am down to a small remaining fragment of 4mm brass sheet, perhaps just enough, at a squeeze for the two saddle tank bottom fittings, but no more. I will require another piece for the right hand well tank, while the left hand side has a compression nut attachment. The company that I originally ordered the brass from used to be happy to cut down to minimum sizes required, but unfortunately they have exhausted their own stock now - so I would have to go elsewhere. Unfortunately, I cannot find anyone that sells anything other than standard size sheets - and that at an eye watering price at the moment too! I am not splashing out on a load of extra material that at this late stage of the build, I would be fairly unlikely to find a use for!
It is approaching the point now where there are a two or three features to complete this project that are notably beyond my own ability or facilities to complete without having to call for some outside assistance. I never cease to be amazed by the generosity of friends, but I am always painfully aware of how easy it is to rather enthusiastically promise help, only to find that other life pressures make it impractical or almost impossible to fulfil. While always grateful for any offers, I would prefer not to ask in the first place!
One such issue that has been bothering me for quite a while is the two cylinder lubricators, looking much like brass flower pots with peculiar lids, and prominently perched up front on the running plates and either side of the smokebox.
As can be seen in the above images, there were two varieties: The original Horwich pots were more tapered, with a deep lip to accommodate the female threaded section, whereas the later type (being demonstrated by my granddaughter on "Wren") were plain sided and slightly broader. Studying all the photographs to hand reveals that both versions seem to have been distributed amongst the entire class until withdrawal, including evidence that some engines carried one of each at the same time.
One problem for me is that the lubricator only has a single point of attachment, being threaded through a hole in the running plate and into the top of the cylinder... and of course, that part of the latter is made of MDF. While there should be enough meat for a screw to bite into, the lid has that "bench vice" type sliding handle... so if the pot is simply turned out of a solid brass lump, (as it only needs to be for the sake of appearance) I reckon with such leverage available to inquisitive fingers, it wouldn't be too long before the entire body works loose!
Besides that particular concern, I would really rather like the lid to be removable anyway, thus revealing the internal workings, complete with some nice, gooey looking, but solid imitation of steam oil within!
Entirely for educational purposes... naturally!
Returning however to the immediate task; I wondered if the serious brass shortage, plus a desire for a 10mm pipe compression fitting might be satisfied at my local B&Q? Admittedly, their prices are a bit steep for everything, but then again, I do enjoy the convenience of a very handy discount card and an equally useful bus-pass to offset much of the penalty!
Picking a sunny day last week, I hopped on a bus, and shortly arrived thereafter to peruse amongst the company's finest brassware products in the plumbing aisle. I was mainly searching for some sort of flange/bracket or cap nut that could cut up and adapted for the "Equilibrium" (official Horwich terminology!) balance pipe fitting.
I found something, and then had one of those "Here, hang on a minute" moments:
A 3/4 inch, female threaded, (weirdly labelled as 1/2 inch?) exterior wall, tap fitting not only provided a neat little baseplate... but the tap socket looked pretty much spot-on size wise for one of those lubricators!
Win, win wahoo!!
I came out with two tap fittings, a pair of blanking caps, and even the hoped for 10mm pipe jobbie, then after a producing quick trace from the G.A's when I got home, set to with the hacksaw...
The brackets (above right) will, after chopping off the third arm and some subsequent fettling, do the twin studded pipe ends quite nicely, whilst the internal bore of the main body turns out to be perfect for our purposes at 12mm!
When scaled down, the hexagonal base of the lubricator also comes out as 12mm, so I was able to round off short sections of pre drilled and tapped 12mm hex in the drill press to form a tight, push fit, solder up solidly and then back in the press to dress down to the final shape with flat and rat tail needle files:
From the outside, the soldered joint between the two parts is well hidden in the coning under the pot bowl, and just at the upper root of the waisted section.
I know it is a slightly different matter with the interior though:
I am also aware that the thread is not only much too coarse for scale, and that it extends all the way down to the bottom of the chamber, but I do take comfort in that still being quite a small object, it will be much easier to open, and then find the thread again when closing!
When I have finally established the precise nature of the internal feed tube, the majority of the chamber will be filled with a set, semi opaque solution to mimic a near full pot of steam oil, so hopefully by then the compromise won't be too obvious?!
I was so much enjoying the process that I quite forgot to photograph some of the sequences, so took some more - and still missed the critical bits! I append them here anyway:
Once the hex is soldered into the factory machined bore, it provides a perfectly centred tail that can then be gripped firmly in both the bench vice and the drill chuck, without any fear of damaging the hollow shell. I did find it easier to remove the peaks off the octagonal grip section of the casting while still on the bench, and definitely before attempting to apply a hand held file to that part of the object when it is spinning in the drill.
There is still a bit of grooving to polish off, and working out the best method of shaping up their little conical, bobble hats from the blanking caps.
I do so like the idea of "upcycling" less obvious items for a new purpose, and while admittedly these were not found, second-hand donations or scrap, at least I now have a pair of these quirky little pots, plus some extra, vital bits of metal for less than a tenner of outlay!
Pete.
(The jammy bodger!)
It is approaching the point now where there are a two or three features to complete this project that are notably beyond my own ability or facilities to complete without having to call for some outside assistance. I never cease to be amazed by the generosity of friends, but I am always painfully aware of how easy it is to rather enthusiastically promise help, only to find that other life pressures make it impractical or almost impossible to fulfil. While always grateful for any offers, I would prefer not to ask in the first place!
One such issue that has been bothering me for quite a while is the two cylinder lubricators, looking much like brass flower pots with peculiar lids, and prominently perched up front on the running plates and either side of the smokebox.
As can be seen in the above images, there were two varieties: The original Horwich pots were more tapered, with a deep lip to accommodate the female threaded section, whereas the later type (being demonstrated by my granddaughter on "Wren") were plain sided and slightly broader. Studying all the photographs to hand reveals that both versions seem to have been distributed amongst the entire class until withdrawal, including evidence that some engines carried one of each at the same time.
One problem for me is that the lubricator only has a single point of attachment, being threaded through a hole in the running plate and into the top of the cylinder... and of course, that part of the latter is made of MDF. While there should be enough meat for a screw to bite into, the lid has that "bench vice" type sliding handle... so if the pot is simply turned out of a solid brass lump, (as it only needs to be for the sake of appearance) I reckon with such leverage available to inquisitive fingers, it wouldn't be too long before the entire body works loose!
Besides that particular concern, I would really rather like the lid to be removable anyway, thus revealing the internal workings, complete with some nice, gooey looking, but solid imitation of steam oil within!
Entirely for educational purposes... naturally!
Returning however to the immediate task; I wondered if the serious brass shortage, plus a desire for a 10mm pipe compression fitting might be satisfied at my local B&Q? Admittedly, their prices are a bit steep for everything, but then again, I do enjoy the convenience of a very handy discount card and an equally useful bus-pass to offset much of the penalty!
Picking a sunny day last week, I hopped on a bus, and shortly arrived thereafter to peruse amongst the company's finest brassware products in the plumbing aisle. I was mainly searching for some sort of flange/bracket or cap nut that could cut up and adapted for the "Equilibrium" (official Horwich terminology!) balance pipe fitting.
I found something, and then had one of those "Here, hang on a minute" moments:
A 3/4 inch, female threaded, (weirdly labelled as 1/2 inch?) exterior wall, tap fitting not only provided a neat little baseplate... but the tap socket looked pretty much spot-on size wise for one of those lubricators!
Win, win wahoo!!
I came out with two tap fittings, a pair of blanking caps, and even the hoped for 10mm pipe jobbie, then after a producing quick trace from the G.A's when I got home, set to with the hacksaw...
The brackets (above right) will, after chopping off the third arm and some subsequent fettling, do the twin studded pipe ends quite nicely, whilst the internal bore of the main body turns out to be perfect for our purposes at 12mm!
When scaled down, the hexagonal base of the lubricator also comes out as 12mm, so I was able to round off short sections of pre drilled and tapped 12mm hex in the drill press to form a tight, push fit, solder up solidly and then back in the press to dress down to the final shape with flat and rat tail needle files:
From the outside, the soldered joint between the two parts is well hidden in the coning under the pot bowl, and just at the upper root of the waisted section.
I know it is a slightly different matter with the interior though:
I am also aware that the thread is not only much too coarse for scale, and that it extends all the way down to the bottom of the chamber, but I do take comfort in that still being quite a small object, it will be much easier to open, and then find the thread again when closing!
When I have finally established the precise nature of the internal feed tube, the majority of the chamber will be filled with a set, semi opaque solution to mimic a near full pot of steam oil, so hopefully by then the compromise won't be too obvious?!
I was so much enjoying the process that I quite forgot to photograph some of the sequences, so took some more - and still missed the critical bits! I append them here anyway:
Once the hex is soldered into the factory machined bore, it provides a perfectly centred tail that can then be gripped firmly in both the bench vice and the drill chuck, without any fear of damaging the hollow shell. I did find it easier to remove the peaks off the octagonal grip section of the casting while still on the bench, and definitely before attempting to apply a hand held file to that part of the object when it is spinning in the drill.
There is still a bit of grooving to polish off, and working out the best method of shaping up their little conical, bobble hats from the blanking caps.
I do so like the idea of "upcycling" less obvious items for a new purpose, and while admittedly these were not found, second-hand donations or scrap, at least I now have a pair of these quirky little pots, plus some extra, vital bits of metal for less than a tenner of outlay!
Pete.
(The jammy bodger!)
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Brilliant. For what it's worth Bsp. is a nominal bore measurement, so half inch is the nominal size of the hole up the middle, meaning the fitting is much larger on the outside.
Pipe is usually measured on nominal bore, tube on outside diameter, caused a few mistakes and a lot of hilarity at work for Newbies.
Pipe is usually measured on nominal bore, tube on outside diameter, caused a few mistakes and a lot of hilarity at work for Newbies.
Peter Insole
Western Thunderer
Rich has some time off work, so he came over yesterday and offered to drive me over to the only model shop left anywhere near us now. Oh dear, what a lovely place to spend an afternoon! I commented to the proprietor that it was going to be a bit difficult dragging each other kicking and screaming out of the store when it came time to go home!
I am still not sure how we both managed to come away with only a few items of essential modelmaking material, and not things that we could ill afford? Our respective wives were probably just as surprised not to witness any of the usual furtive behaviour or feeble excuses on our return as well?!
Today, I was keen to keep up the momentum by sorting a problem with the lubricator lids.
Utilising ordinary brass blanking caps, with their threads conveniently matching the former tap fittings seemed like a perfect solution, but I was dismayed to discover that the hollow bores were cut far too deep, and there were consequently sections with precious little metal under the hexagonal heads. I also realised that I would need something small enough to hold the caps in the drill chuck for shaping up.
After some thought, and yet another rummage, I found a 1/4 inch thick piece of brass strip in the odds and sods pot, with just enough overall dimensions to cut two circles of the required diameter - plus two short offcuts of 8mm brass rod. It would almost seem as if those bits belonged together, but had been hanging around for years waiting for this moment to combine?
For the life of me though, I could not find the appropriate bit to drill the holes!
I had to whizz down the end of each rod to an interference, squeeze in the vice fit instead.
I wanted the joints really nice and tight so that the rods would hold firmly during the subsequent procedures, with only one soldering operation required to solidly set the whole assembly in place.
A simple, fuss free method of scribing a deliberately outsize cutting line was to hold the scriber on the flat of a handy nut. The marks may have been a bit fluffy after two or three turns, but because the point could not travel any further inboard, they were all that was needed to ensure initial centring.
It does appear that I was cutting with the crude hacksaw rather dangerously close to the line in places, but I had made allowance for plenty of material to come off during the filing down on the bench, (below) and final spin off in the drill press.
After "turning" the discs down to a sliding fit in the cap bores, (forgot to shoot that bit) I started to remove the hex from the caps by further filing...
Although I was filing down at an angle from the centre, the waste disc was wafer thin right across the diameter at the stage when it started to drop into the bore!
I did fear that the rod might turn out to be slightly off centre after soldering up, but it settled in just fine.
For once, the soldering was a pleasure too - as it flowed quite sweetly and found all the right places!
Throughout all this I still could not be certain that the "building up" approach would actually work, so I started the final shaping job slowly - and with some trepidation.
Phew! There was enough metal to form a smooth cone!
While some solder is still showing at the centre stub, (at this stage) the potentially prominent and terribly worrying joint on the top surface of the lid has turned out, by a stroke of good fortune, to be practically invisible.
Pete.
I am still not sure how we both managed to come away with only a few items of essential modelmaking material, and not things that we could ill afford? Our respective wives were probably just as surprised not to witness any of the usual furtive behaviour or feeble excuses on our return as well?!
Today, I was keen to keep up the momentum by sorting a problem with the lubricator lids.
Utilising ordinary brass blanking caps, with their threads conveniently matching the former tap fittings seemed like a perfect solution, but I was dismayed to discover that the hollow bores were cut far too deep, and there were consequently sections with precious little metal under the hexagonal heads. I also realised that I would need something small enough to hold the caps in the drill chuck for shaping up.
After some thought, and yet another rummage, I found a 1/4 inch thick piece of brass strip in the odds and sods pot, with just enough overall dimensions to cut two circles of the required diameter - plus two short offcuts of 8mm brass rod. It would almost seem as if those bits belonged together, but had been hanging around for years waiting for this moment to combine?
For the life of me though, I could not find the appropriate bit to drill the holes!
I had to whizz down the end of each rod to an interference, squeeze in the vice fit instead.
I wanted the joints really nice and tight so that the rods would hold firmly during the subsequent procedures, with only one soldering operation required to solidly set the whole assembly in place.
A simple, fuss free method of scribing a deliberately outsize cutting line was to hold the scriber on the flat of a handy nut. The marks may have been a bit fluffy after two or three turns, but because the point could not travel any further inboard, they were all that was needed to ensure initial centring.
It does appear that I was cutting with the crude hacksaw rather dangerously close to the line in places, but I had made allowance for plenty of material to come off during the filing down on the bench, (below) and final spin off in the drill press.
After "turning" the discs down to a sliding fit in the cap bores, (forgot to shoot that bit) I started to remove the hex from the caps by further filing...
Although I was filing down at an angle from the centre, the waste disc was wafer thin right across the diameter at the stage when it started to drop into the bore!
I did fear that the rod might turn out to be slightly off centre after soldering up, but it settled in just fine.
For once, the soldering was a pleasure too - as it flowed quite sweetly and found all the right places!
Throughout all this I still could not be certain that the "building up" approach would actually work, so I started the final shaping job slowly - and with some trepidation.
Phew! There was enough metal to form a smooth cone!
While some solder is still showing at the centre stub, (at this stage) the potentially prominent and terribly worrying joint on the top surface of the lid has turned out, by a stroke of good fortune, to be practically invisible.
Pete.
Peter Insole
Western Thunderer
Thank you Giles. I'll never know how I managed to get away with it though!
Pete.
Pete.
Peter Insole
Western Thunderer
It felt like I was on a roll with the second lubricator, although I paid dearly for it later with a terrible headache. I principally blame the sessions of soldering in the cellar for that!
I would like to think that the end result was worth the effort? It was certainly a relief when the main part of the job was done.
Having gained the confidence that there was indeed enough material available for a smooth and continuous slope with the first attempt, I was able to reduce the angle and introduce more of a curving taper to the centre boss on the second.
The latter shape would appear to more closely resemble the earlier pattern of lubricator, although I am quite sure they will get mixed up in service - very much as in the prototype?!
Drilling awkwardly large holes centrally through the fiddly little bosses was a rather fraught affair, as all the while I was constantly aware that even a minor error at this late stage would mean an awful lot of further grief to put it right!
Although neither of the lids are precisely accurate copies, they were the best that I could manage at the time. Hopefully, the result is close enough to capture something of the character of these little beasts anyway?!
As if to prove that I like living "on the edge", (
) please can I make plea for assistance with information from anyone here who might know the answer to, or who have access to something similar to a query?
These lubricators were only fitted (including retrospectively) to the eight Horwich locomotives, so the opportunity for close inspection of "Dot" at Tywyn, with it's original (1887) pattern still in place was of no help. The last time I was at the NRM, I found that the lids had been (perhaps very sensibly to avoid the unfortunate prevalence of theft) been jammed firmly down. The lever holes were so badly worn by frequent fiddling fingers that any attempt to open the pots would almost certainly have led to a break!
I would really like to find out what the internal arrangements are, and this is turning out to be a most vexing conundrum!
Searching online for variations on the theme of "steam cylinder lubricators", "oilers", "Furness" or "tallow cups" indicates that Google has obviously never heard of such things, and merrily puts up hundreds and hundreds of bewilderingly irrelevant results!
What I can say with assurance is what they are not!
The lubricators are attached to lugs formed as part of the cylinder castings, and so placed to directly deliver oil, or tallow into the upper centreline of the bores.
Perhaps unsurprisingly, bearing in mind the above observation, there are no air holes in the screw down lids, thus precluding any form of "drip" or "wick" feed.
The external design of the pots do however closely resemble images quoted to be of the "Furness" type - but without the additional flow control screw that I assume was an integral part of the patent. (?)
I can only so far conclude that they are a simple form of "displacement" type, relying on condensing saturated steam... but then again, there are neither shut off, or essential drain valves present!
So did they just have an empty chamber with a small feed hole at the bottom, (unlikely?) or was there a vertical tube that was open at the top, or a blanked one with a strategically placed hole in the side wall??
Any replies will be most welcome indeed!
Pete.
I would like to think that the end result was worth the effort? It was certainly a relief when the main part of the job was done.
Having gained the confidence that there was indeed enough material available for a smooth and continuous slope with the first attempt, I was able to reduce the angle and introduce more of a curving taper to the centre boss on the second.
The latter shape would appear to more closely resemble the earlier pattern of lubricator, although I am quite sure they will get mixed up in service - very much as in the prototype?!
Drilling awkwardly large holes centrally through the fiddly little bosses was a rather fraught affair, as all the while I was constantly aware that even a minor error at this late stage would mean an awful lot of further grief to put it right!
Although neither of the lids are precisely accurate copies, they were the best that I could manage at the time. Hopefully, the result is close enough to capture something of the character of these little beasts anyway?!
As if to prove that I like living "on the edge", (
) please can I make plea for assistance with information from anyone here who might know the answer to, or who have access to something similar to a query?These lubricators were only fitted (including retrospectively) to the eight Horwich locomotives, so the opportunity for close inspection of "Dot" at Tywyn, with it's original (1887) pattern still in place was of no help. The last time I was at the NRM, I found that the lids had been (perhaps very sensibly to avoid the unfortunate prevalence of theft) been jammed firmly down. The lever holes were so badly worn by frequent fiddling fingers that any attempt to open the pots would almost certainly have led to a break!
I would really like to find out what the internal arrangements are, and this is turning out to be a most vexing conundrum!
Searching online for variations on the theme of "steam cylinder lubricators", "oilers", "Furness" or "tallow cups" indicates that Google has obviously never heard of such things, and merrily puts up hundreds and hundreds of bewilderingly irrelevant results!
What I can say with assurance is what they are not!
The lubricators are attached to lugs formed as part of the cylinder castings, and so placed to directly deliver oil, or tallow into the upper centreline of the bores.
Perhaps unsurprisingly, bearing in mind the above observation, there are no air holes in the screw down lids, thus precluding any form of "drip" or "wick" feed.
The external design of the pots do however closely resemble images quoted to be of the "Furness" type - but without the additional flow control screw that I assume was an integral part of the patent. (?)
I can only so far conclude that they are a simple form of "displacement" type, relying on condensing saturated steam... but then again, there are neither shut off, or essential drain valves present!
So did they just have an empty chamber with a small feed hole at the bottom, (unlikely?) or was there a vertical tube that was open at the top, or a blanked one with a strategically placed hole in the side wall??
Any replies will be most welcome indeed!
Pete.
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Brian McKenzie
Western Thunderer
After decades of not taking sufficient care to minimise dust, fumes and vapours from various hobby activities, my lungs now get bothered when soldering. Some fluxes are more detrimental than others - but its only good ventilation that improves this situation - so please take care.
I do worry about those who are doing extensive soldering work, especially when tucked away in smallish workspaces.
-Brian McK.
Giles
Western Thunderer
Hi Pete,
I think they would almost certainly be simple displacement, with internal tube rising to say 3/4 - 7/8 of the available height. Obviously unregulated, and without a drain, the top is nicely wide to accept a syringe to suck the condensated water out when refilling, which was a common thing to do even with Wakefield lubricators anyway to make sure they weren't inadvertently filling with condensates steam/water due to a stuck non return valve.
I think they would almost certainly be simple displacement, with internal tube rising to say 3/4 - 7/8 of the available height. Obviously unregulated, and without a drain, the top is nicely wide to accept a syringe to suck the condensated water out when refilling, which was a common thing to do even with Wakefield lubricators anyway to make sure they weren't inadvertently filling with condensates steam/water due to a stuck non return valve.
Peter Insole
Western Thunderer
Thank you so much Giles, 'tis much as I had suspected and indeed could have hoped for!
This little image of what the supplier referred to as a "dead-leg lubricator" for Mamod locomotives (!) came up in yet another searching session last night:
(image reproduced here for illustrative purposes only)
The thing is as much as you describe; with no facility to control the flow or drain the condensate - and in this particular model form, is simply made by carrying the single copper pipe connection from the cylinders right up through the chamber from the bottom. The (undressed) end is just open at the top. I am assuming here that when the cap is screwed down, there is a relatively small gap between the two parts, which may have a marginally restrictive effect. I do suspect in this case however that may be somewhat arbitrary though?!
I will still hang fire for a while longer, just in case someone can find a particular patent drawing or suchlike that might be close enough to the specific item of interest!
Pete.
This little image of what the supplier referred to as a "dead-leg lubricator" for Mamod locomotives (!) came up in yet another searching session last night:
(image reproduced here for illustrative purposes only)
The thing is as much as you describe; with no facility to control the flow or drain the condensate - and in this particular model form, is simply made by carrying the single copper pipe connection from the cylinders right up through the chamber from the bottom. The (undressed) end is just open at the top. I am assuming here that when the cap is screwed down, there is a relatively small gap between the two parts, which may have a marginally restrictive effect. I do suspect in this case however that may be somewhat arbitrary though?!
I will still hang fire for a while longer, just in case someone can find a particular patent drawing or suchlike that might be close enough to the specific item of interest!
Pete.
Giles
Western Thunderer
The lubricator must be filled to the top of the tube so that the cylinder benefits from the very first influx of steam. Not quite arbitrary length, as the gap between the top of the tube and the underside of the cap x the diameter (the steam space) will dictate how much oil gets fed to the cylinder. The lower the pipe the more steam space and therefore condensate, the more oil will be fed.