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 May 16, 2021 16:51:55 GMT
An interesting discussion....it is also important to consider the wheel loading at each end of each axle. What you don’t want is a vehicle’s weight being carried in such a way that diagonally opposite wheels are “unloaded”....this can be a major factor in flange climb type derailments full size, influenced by spring/suspension setup, frame twist etc.
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 May 11, 2021 22:33:00 GMT
Personally I use just flange sealant on the cylinder covers of my 9F, which are cast iron, held on by countersunk screws. When the screws are removed, a sharp tap on the edge with a flat punch has always removed them quite easily without damage. It might be a different story with a softer material like gunmetal and especially if studs are used, as the sealant might get round the studs and make the covers more reluctant to come off? If this is likely, then a gasket could be the better method.
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 May 11, 2021 17:29:58 GMT
I have used Loctite 577 successfully for years as a thread sealant but have recently thought that when 577 runs out, I’ll try 567 instead. The 577 is fairly easy to dismantle. For flanged fittings, I use 574, also with great success.
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 May 8, 2021 17:42:06 GMT
Hi, my 5” 9F has dampers and they definitely help you control the steaming rate. The ashpan is much simpler than that on a Britannia, but if you want to incorporate them....go for it! The drawing for the ashpan on my 5” Jinty showed it open to the rear with no damper. As it has the usual “drop” arrangement and damper linkage would be awkward, I just made a damper door and fixed it in a partly open position by guesswork. A recent run following the steam test has reminded me to close it a bit more, as the engine steams very freely.
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 May 8, 2021 12:20:45 GMT
Hi Richard, yes the photo thing is a common problem for people....you have to upload the photo to a hosting site (I use imgur which is free at the moment), then in the “Reply” (not Quick Reply), there is a button to be able to insert a link to your photo, which is then brought to the forum from your hosting site. Bit of a pain but there is a sticky, once you open “General Chat” on how to do this.
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 May 7, 2021 22:52:52 GMT
Hi Mike, I’ll give you my thoughts on your questions:-
Gunmetal is an alloy of predominantly copper & tin and is extremely resistant to corrosion and a very good bearing material (also very expensive these days)! Gunmetal cylinders seem to be quite happy with gunmetal pistons in our models.
I’ve only got the Jinty with gunmetal cylinders/pistons and it uses traditional 3/16” square graphited packing, tightly packed into 3/16” square grooves, however many people advocate and successfully use o rings as a modern alternative. Presumably wherever the ‘rings” would fit, they don’t have to cross the steam ports at the cylinder ends?
I’m not sure about stainless valve bobbins working in gunmetal bores, I have no experience of that combination but again, many people don’t have any rings on these, just relying on a good fit. The valve heads do have to cross the ports, so any rings if fitted, have to accomodate this.
On the Warnett 9F, there is a 1/32” gasket between the cylinder block and it’s backplate, but there is no gasket between the backplate and the frame. This is as per drawing and is taken into account to locate the centreline of the cylinder bore in the right place to line up with everything else that matters....like slidebars, main crankpins etc....what do the Perrier drawings show in this respect? I think Warnett described it as being a heat insulator, probably to keep the cylinders hot and is just normal gasket material (the early model designers often referred to “Hallite”, but don’t know if that’s still around these days).
Warnett specified ptfe seals around the 9F piston rods, but that didn’t work well for me and it wasn't long before I modified the arrangement to use traditional graphited packing. Since doing that a long time ago, they’ve never given any trouble. I’m sure an o ring would work here, but the problem would be having to take the crosshead off to do a replacement if ever needed! That was the problem with those ptfe seals, but now I could repack the glands easily if I ever have to.
Hope this helps you a bit! Let me know if you need any further assistance.
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 May 6, 2021 20:36:23 GMT
Hi, that’s good news but is there any chance of a photo of the valvegear arrangement? I am still interested to know what’s different to the Joy valvegear on my Austin 7, as shortening the reach rod on that would have the effect of reducing the maximum cutoff in forward, whilst potentially increasing the maximum cutoff in reverse. I have had a quick look online for photos of the G2 valvegear but haven’t found any. When we were restoring 9F 92214 in the early 1990’s, the preserved G2 was alongside us for a long time, but of course back then I never took much notice of it!
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 May 5, 2021 18:56:48 GMT
Hmmmmm now that could be a bit of a problem, as there is not much surplus material and that is where the 1/16 edge is ? Regards Paul Hi Paul, could you fill those blowholes with silver solder? 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 May 4, 2021 22:29:27 GMT
I‘ve recently been “binge watching” youtube videos about the USS New Jersey, one of the WW2 Iowa Class Battleships preserved in the USA. It has a well equipped machine shop , with some machines having been replaced in the re-commissioning of the 1980’s, but including some machines from 1942 still used for restoration work today..... Machine ShopCheers 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 May 3, 2021 22:28:21 GMT
Hi, I’m in a similar situation with my part built Austin 7.....ie I don’t really know much about Joy valvegear! Although the “real” Austin 7’s had Walchearts gear, this model has for unknown reasons been built with Joy gear. One thing I can be fairly sure of is that the adjustment of the “ride height” of the driving axleboxes is fairly critical, but other than that, I haven’t really gone into much detail of the gear’s operation yet. When I first acquired it, it ran on air reasonably well and since then it’s been dismantled and put aside whilst I build its tender.
Assuming you are referring to the reach rod from the cab reverser to the curved link, wouldn’t shortening it on your G2 have the same effect on forward running as just “notching up” whilst allowing more cutoff in back gear? Having said that, I’m not at all familiar with the layout of the G2’s valvegear and it might be different to mine!
I could do with reading up on this gear, to better understand the way to properly set it up! Maybe there’s a good write up somewhere?
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 May 2, 2021 17:03:56 GMT
Hi Mike, your rods look very well made and I also love the attention to detail and how you have crafted your nuts! The problem with small split pins like that is that when cleaning, they can easily get caught in the cloth/rag and the tails get bent. Good job you're not building a 9F, you'd have to have a week in your darkened room!
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 Apr 30, 2021 18:55:00 GMT
Hi, I use nitrile rubber balls very successfully in boiler clack valves, but have not tried one in a whistle valve! Silicon nitride are very good in other fittings like safety valves, whistle valves etc. You only need to press the ball lightly onto its seat, use a piece of brass that will fit through any threads, to reach the ball. You can apply the “squeeze” in a vice.
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 Apr 30, 2021 16:33:58 GMT
Can you carefully re-cut the seat? Then obtain a silicon nitride ball for it....they are much more accurately “round” than some so called stainless balls. I always press a ball onto its seat, I never seem to get a good seal by giving them a tap....as is often suggested.
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 Apr 29, 2021 22:25:55 GMT
Hello lennart, on my BR Standard 9F loco, the crosshead pins have to be removed / refitted from between the spokes and the design has a hole drilled into the inside end of the pin, which was then “broached” out to a hexagon pocket, by pressing a piece of hexagon wrench (an Allen Key) into the hole. It is then straightforward to prevent the pin from rotating, whilst tightening gently the nut on the outside (smaller diameter like yours). The real things have to come out this way, but they have a keyway arrangement to prevent the pin rotating.....this would be harder to reproduce in model form!
If you can access the inside end of the pin with a screwdriver, even one bent over at 90 degrees, that would be just as good.
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
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Post by don9f on Apr 28, 2021 15:59:04 GMT
I mentioned recently on my “Austin 7” thread that I had been building Julie a Tortoise House....I didn’t mean that literally! 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 Apr 27, 2021 19:46:05 GMT
Hello all, its been about 10 weeks since my last update to this thread, many apologies for that but there are all sorts of reasons why there hasn't been much progress since then. I had a hernia repair operation back in February, something that had been troubling me for several years, but was getting much worse. This meant a further spell of not being allowed to drive, plus complications due to the "wound" not healing properly at first, with daily hospital visits for dressing changes etc. for a couple of weeks. Since all that cleared up there have been the inevitable gardening duties, plus the biggest distraction of all being the construction of a "Tortoise House", for Julie, who has always loved the creatures and has now acquired one that's been occupying the spare room until last Sunday. The damn thing still isn't finished and I've been on with it since 8th March! It's electrically heated, has a sun lamp on a timer and a wifi camera for remote monitoring, which needed a wifi extender gadget to get decent signal:- Anyway enough of that....during the last two months I have managed the odd hour here and there on the Austin 7 and have slowly been preparing the various sub-assemblies of the tender brasswork for final assembly and soldering, which I have just made a start on this week. I'm afraid I haven't taken any photos until today, but it was mostly just tedious drilling, rivetting 1/4" brass angle, tapping 8ba threads, trial assembling and so on, interspersed with a bit of machining of round bits, so nothing really interesting. First job was to attach the two intermediate baffles/stiffners to the soleplate (the splashers had already been soldered on some time ago), then attach the well tank, after which this sub-assembly could be soldered up (sorry the first one's a bit blurred):- Here are the front and rear plates ready to be assembled to the sides:- The sides themselves:- This next piece is part of the tender back, which was a bit more involved and therefore more interesting to make. It includes the machined bits, ie the vent pipes, plus the scoop dome and the filler neck/cover....also some bent angles that stiffen the rear of the coal space and the reinforcement to the tank lifting points:- This final photo for today shows the detachable (unfinished) tender front, with lockers, plus some fabricated "tee" angles that will reinforce the sections of the tender sides that will project above the floor of the coal space:- That is where I am as of today, hopefully will get a bit more assembly done over the next few days (tortoises permitting)! 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 Apr 26, 2021 20:56:56 GMT
Hi, you may need to remove the crosshead pin(s) on the completed loco in the future for maintenance etc. If they have to pass through the wheel spokes from the inside of the crossheads, this could limit the size of pin “head” that will fit?
With a smaller diameter on the outside, the pins can be secured:- a) with no head required and b) by not “squeezing” the crosshead side plates together
Just some things to think about....
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 Apr 26, 2021 20:16:37 GMT
The Light Cruiser HMS Belfast, moored near Tower Bridge in London has its workshop as part of the tour below decks. I haven’t been for many years, but I recall that there are quite a few machines on board that you can inspect....as Nobbysideways says, there are some photos available if you Google.
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 Apr 21, 2021 16:30:10 GMT
David and Lily. Lily resting after a RIVETING DAY. Groan. Hi Roger, I was looking for a copy of the drawing for that fabricated design of swab box, but unfortunately the one I did find was presumably for an earlier, cast gunmetal design, so no use to you. However that photo of David’s is a great help and you could probably work out all the dimensions from it, should you wish to go ahead! 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 Apr 19, 2021 19:33:31 GMT
I’ll see if I can lay my hands on the drawing of it for the 9F....it looks very similar to that on 1501. There may be differences in hole centres/piston rod dia. obviously!
Cheers Don
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