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 9, 2022 15:37:29 GMT
On the BR Standards and other types, there is no actual bearing in the cylinder rear cover, just a clearance hole and then the gland that is free to “float” and follow the piston rod. The 9F I am familiar with for example had a bronze slipper at the bottom of the piston between the two rings, backed by springs and this (in theory) took the weight of the piston to help it run up and down centrally in the bore in a straight line. In practice, these things wore quite quickly and the pistons then probably made contact with the bottom of the cylinder liner. The allowable difference between the piston diameter and the 20 inch cylinder bore is nominally 3/16 inch.
Cheers Don
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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 9, 2022 15:18:43 GMT
I agree it looks like it’s the planet Uranus.
Cheers Don
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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 9, 2022 14:59:49 GMT
Hi Phil, that looks to be a very sturdy ashpan! You are probably aware that where those groups of holes are in the two end plates, is where the damper doors would be. They are working doors on my own Warnett model and I do find them useful to help control the steaming rate. In reality I usually only open the rear door and then only by about a half.....but then there are other places on mine where air can get in! The whole thing is not an air tight fit to the foundation ring and the discharge hopper doors don’t make a perfect seal either.
Cheers Don
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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 8, 2022 20:46:35 GMT
Hi, from time to time the subject of the 9F tyre profiles crops up....particularly the profile of the "Flangeless", centre drivers. When I built my 5 inch gauge Les Warnett 9F model back in the 1980's, I just machined the flangeless profile as per the drawings and this simply followed the same coned profile of all the other wheels. Part way through the build of this model, I became involved with the restoration of the "real" 92214 and I eventually learned that, whilst when first built, the 9F's did have the flangeless profile coned like the other wheels, this was modified at some point to a different "cylindrical" sort of profile. For anyone interested, the following profile drawings for the 9F are taken from the old "MT 276" that was one of the Maintenance Documents that was relevant to Private Owner vehicles running on British Rail infrastructure. (This document is available on-line). So, in steam days, the pony truck, leading drivers, trailing drivers and the tender tyres all had the "A" profile, which had the normal 1 in 20 coning (2.86 degrees). For many years and still today, the equivalent to this is the "P1" profile. The leading intermediate and trailing intermediate drivers had the "E" profile which was the same general shape as the "A", but had a slightly thinner flange....including about 1/8" skimmed off the back face. This would affect the way these wheels interacted with check rails on curves and through pointwork etc. This feature, coupled with greater sideplay on these two axles, enabled the 9Fs to negotiate a minimum 4.5 chains radius curve (99 yards or 90.5 metres radius). The equivalent to this today is the P9 profile, although it's not actually exactly the same. Finally the much talked about "Flangeless" centre drivers. These eventually had the "X" profile as related above. This axle actually had very little sideplay but of course it didn't need it and note that the width of the tyre is a bit greater than the others, although the "back to back" dimension is the same, so the extra width is on the outside. There is no modern equivalent to this profile, so it's regarded as a "Special". I assume that anyone re-profiling 9F centre drivers has to either make use of a special CNC program, or template (if the lathe uses such a thing), or create the profile manually? During our ownership of 92214, we once explored the possibility of having the drivers re-profiled at the Ilford Car Shed's Ground Wheel Lathe, for which someone there was creating a special CNC program for the "X" profile, but the engine was sold before we ever really needed the work doing! In the other "Wheels video" thread , there were references to wheels "slipping" on curves, either due to the coning not being enough to cope with the differential rail lengths, or in the case of the flangless wheels not having coning at all!, but another factor touched on that is particularly relevant here, is that the wheelsets of a 9F are not properly radial to the centre of a curve....due to the length of the wheelbase etc., so some slipping is bound to occur anyway as the wheelsets adopt a slight "crabbing" effect. From my own experiences, when negotiating a sharpish curve on a dry day, 92214 would make this phenomenon very "audible", whereas on a wet day, it would just glide round the same curves almost silently! Hope this has been of interest.... Cheers Don
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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
|
Post by don9f on Jan 5, 2022 23:45:20 GMT
They look superb!
Don
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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
|
Post by don9f on Jan 5, 2022 23:37:43 GMT
Unfortunately I don’t have a good photo of a flangeless wheel and although I have “lightened” it up a bit you still can’t see the profile well in this one of 92214 on its “Gauging run” after arrival at the East Lancs Railway in 2005. It’s moving through a curve of nominal 5 3/4 chains radius of well maintained track....but you can see just how much the flangeless wheel moves across the railhead. It did derail and rerail itself once on one of the curves in the loco shed yard whilst it was there! Cheers Don
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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
|
Post by don9f on Jan 5, 2022 22:42:09 GMT
My question is are the non flanged wheels on the 9F coned or parallel? I suspect that they must be coned, as the rails also lean inwards, offering maximum contact to the coned wheels. This has cropped up before and as far as I know, they were coned when the 9F was first introduced, with the same angle etc. as the other driving wheels, but after the tendency for the flangeless wheels to derail on poorly maintained track became obvious, the profile was changed to one with a parallel section in the centre of the tyre (about a third of it) and angled (or coned) sections either side of this, plus the usual chamfers at front & back edges of the tyre. This was known as the BR “X” profile and presumably gave these wheels a better chance of rerailng themselves. The tyres of the flangeless wheels were slightly wider than those of the other wheels, but I don't know if they were like this originally or a later modification. Cheers Don
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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
|
Post by don9f on Jan 4, 2022 17:50:42 GMT
Looks and sounds pretty good to me....well done!
Regards Don
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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
|
Post by don9f on Jan 2, 2022 17:46:24 GMT
Incidentally, there is something distinctly odd about the 4th axle set, although one has to look very closely. I will treat it as a New Year quiz and see if anyone can spot the oddity - and even perhaps explain it, which I can't! 203123825_3258624701047385_5538263824916745246_n by malcolm brown, on Flickr Best wishes Malcolm Hi Malcolm, is it to do with the orientation of the flycranks to the holes in the wheelcentres? Cheers Don
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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 1, 2022 19:19:03 GMT
Yes, well done Malcolm....onwards and upwards ! Look forward very much to more on this project in 2022.
Cheers Don
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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 Dec 29, 2021 16:00:13 GMT
Hi Malcolm, I’m no expert but I don’t see any reason why your proposal shouldn’t work. Many years ago I helped a fellow modeller with a 5” Black Five boiler that had a leaking superheater flue on the firebox tubeplate (found like yours, after initial test). With background heat and a gentle oxy acetylene flame, the defective joint was re-soldered, the boiler cooled very slowly and it never gave any more trouble.
Cheers Don
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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 Dec 23, 2021 22:55:17 GMT
Commiserations on that mishap....must have been very disappointing! Anyway well done for the rest of it. You are racing ahead of me, as I’m stalled now on my 7F boiler, waiting until the New Year to be able to “borrow” the Oxy-propane pepperpot set again to do the foundation ring and smokebox tubeplate.
Merry Christmas Don
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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 Dec 23, 2021 22:43:33 GMT
Thanks Roger, not only for the fascinating journey itself, but also for all your hard work at the computer, to enable us to follow along!
Merry Christmas
Don
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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
|
Post by don9f on Dec 18, 2021 18:58:57 GMT
Amongst other things, successful silver soldering needs:- The parts clean The joints properly fluxed The right amount of heat “Blobs” suggest that maybe the silver solder melted before the materials of the joint themselves were hot enough. What size and grade of silver solder were you using? I find that a good grade for jobs like pipe unions etc. is 455, which melts at around 630 degrees C. It is available in small diameters (eg 0.5mm or 0.7mm) and this melts easily into the joint....if it is hot enough! Using larger diameter solder on small parts is more difficult as it is best to get the parent metal to melt the solder, not the flame. Check this out for hints and tips about silver soldering. Cheers Don
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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
|
Post by don9f on Dec 14, 2021 20:20:30 GMT
I have two No 2 (11oz) injectors from Maccmodels (don’t know who makes them) on my 5” gauge 3F tank loco. It’s quite a small boiler but these two work well on it. They can be used with 5/32 pipe, although I actually used 3/16, but it is only just over 1/8 bore.
Cheers Don
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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
|
Post by don9f on Dec 14, 2021 19:44:56 GMT
Regarding colours. IIRC there was a bit of a 'conversation' in one of the mags that claimed that the smaller the gauges the more 'non authentic' were the colours even though the paint was the same as the full size loco. and it had to be darkened/lightened ( cannot remember which) to match the full size loco Is there any truth in this, or was it someone looking for an argument? Bob (92220) has mentioned this sort of thing before, I recall him talking about having to change the gloss level of the paint, as the scale of the model changes. That possibly changes the way our eyes see the colour? Hopefully he’ll come back with more info. Cheers Don
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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 Dec 10, 2021 20:03:19 GMT
Ok thanks Keith, that return crank on the RH side looks “in the ball park”. As I said, it wasn’t really possible to see the return crank on the LH side in your previous photo, but hopefully its ok too. Maybe you can look at the things John asked about and report back.....also possibly to my question about setting a valve bobbin in its mid position, when both valves should be closed and see what happens when you pressurise the steam (air) inlet to just that side? Maybe you could bring it to Staffordshire 😀
Cheers Don
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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 Dec 10, 2021 19:38:42 GMT
Hi Malcolm, thank you but I do sometimes have to have a “second go” at some joints to get them right! Also when soldering the sidestays inside the firebox, with all the heat coming back at you and the awkwardness of working inside the narrow box, I missed one !
Cheers Don
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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
|
Post by don9f on Dec 10, 2021 18:18:38 GMT
Hi all, sorry I’m a bit slow in updating this thread but back in late July, I had just about finished the tender and was waiting for the etched plates to arrive from Diane Carney, so made a start on the boiler. The plates came a few weeks ago and as usual, they are excellent. My chosen number for the engine is 49508 for no other reason than it was the last one to be withdrawn....lasting until Jan 1962, allocated to Agecroft shed in the Manchester area. The boiler is to the design of Nigel Thompson, for the 5” gauge LNWR 0-8-0 “Wessie”, but it is broadly similar to what is required for an LMS 7F and is really very similar to the 3F boiler I built about 3 years ago, only a bit bigger! It is quite “heavily engineered” in terms of its firebox side stays and utilises very robust girder stays for the top of the firebox. I got the boiler kit from Western Steam earlier this year. All the threaded bushes are in PB102 bronze, the dome bush being SAE660. These were all soldered into place using 438 grade silver solder and Tenacity No5 flux. The same grade was used to join the throatplate to the barrel. Thereafter, 455 grade was used and I am currently at the stage where the inner firebox and tube nest are all fixed into the barrel and outer wrapper. The girder stays require a lot of care in their construction and fitting to ensure a good fit, both the top and bottom flanges being secured with a total of 72 home made bronze 5ba screws! Fixing the girder stays to the top of the inner firebox was straightforward and to ensure sound joints between the girders and the outer wrapper, which can be troublesome, I used a borrowed oxy propane “pepper pot” nozzle, plus provided background heat via my own large propane burner and the job went very well (in my opinion). There are a total of 127 3/16” dia stays in the firebox....the marking out, drilling, deburring & countersinking took ages and I was pleased when that lot was finished! To keep the tube nest in roughly the right position through the silver soldering so far, I made a dummy tubeplate from 16g brass. This stopped any tendency for the tubes to sag and move out of position. Well that brings you up to date, next job is to solder the outsides of the sidestays, the horizontal stays, then present for a further BI inspection, before moving on to the backhead, foundation ring etc. Cheers Don
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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
|
Post by don9f on Dec 9, 2021 20:08:08 GMT
I have thought about something similar in the past, but could not work out how to adequately tighten the screws. Do you have any ideas about that? A good point....it would rely on enough friction between the screw and the hole it fitted in, plus the nut not being a tight fit! On the real thing I talked about, the shank of each screw was coated in red lead (I seem to remember) and tightened up with an impact wrench. I do recall that a few of the domed heads (out of over 180) had to be gingerly held with mole grips until getting “a bite”, but obviously not so easy on a model. Cheers Don
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