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Post by 92220 on Dec 28, 2018 9:32:37 GMT
Hi Roger.
That hook is looking good!! You mentioned that you had made the hook slightly oversize in the area of the hole for the chain link. I don't know what material you used for the hook, but I was also a bit concerned about mine, so I bought a piece of EN24T 1.1/4" dia bar and machined it out of that. EN24T is 44tonne tensile and can be heat treated to reach 100 tonne tensile, which is plenty strong enough, even in the 'T' condition, for a scale hook. It's interesting to see that 1501 doesn't have a British Railways design hook, although it was made in BR days.
Best wishes for the New Year,
Bob.
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Post by Roger on Dec 28, 2018 9:37:43 GMT
Hi Roger. That hook is looking good!! You mentioned that you had made the hook slightly oversize in the area of the hole for the chain link. I don't know what material you used for the hook, but I was also a bit concerned about mine, so I bought a piece of EN24T 1.1/4" dia bar and machined it out of that. EN24T is 44tonne tensile and can be heat treated to reach 100 tonne tensile, which is plenty strong enough, even in the 'T' condition, for a scale hook. It's interesting to see that 1501 doesn't have a British Railways design hook, although it was made in BR days. Best wishes for the New Year, Bob. Hi Bob, I made mine from Cold Rolled Mild Steel plate, so it's a bit stronger than free cutting bar. Having made it, I don't think it's going to be a problem, but I'll have to wait and see if it gets bent in service. I somehow doubt it, it's pretty sturdy. At least I have the programs and tooling to make another pair if necessary. Actually, there's no point in making the front one any stronger. Best wishes to you too, I hope to catch up with you in person some time in the coming year. |
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stevep
Elder Statesman
Posts: 1,073
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Post by stevep on Dec 28, 2018 10:14:42 GMT
I think the ban on the use of chain link couplings on many miniature railways is down to two factors. The potential to snap a chain when pulling away is one. The other is that the gap between the trolleys will close up on over-run. The potential to crush fingers is negated with a solid bar coupling.
I remember going to the old Bournemouth society track with another club member, who was not allowed on the track because he only had a three link coupling on the back of his tender. He was not amused.
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Post by jon38r80 on Dec 28, 2018 13:24:17 GMT
A vacuum cleaner or vacuum pump does seem to be the best idea. I found using an air jet from the compressor just spread the swarf everywhere even though I have 3 sides protected. I have made a shield out of cardboard stuck on to the table with Gorilla tape. Easy to remove and adjust and stops all the swarf from getting on the bellows, jogger and keyboard. I can see experimenting with a few 3D printed vacuum attachments that shroud the nose of the spindle. You can dream up all sorts of long bristled curtains that surround the work too, but that makes it hard to see what's going on. I like the idea of just an occasional turning on of the vacuum, that might work ok, but it's still noisy. In the end, I'll probably end up living with the swarf on the job. It's easy to get paranoid about keeping the area clean so it doesn't keep ingesting and re-cutting swarf, but for roughing, that's really not important. If you clean up before finishing, the last pass produces very little swarf and I've not found that to be an issue. In the case of a printer the ink is squeezed along a narrow bore plastic pipe in a pumping fashion , it is a sort of pump rather than just a metering device, I dont think the cam rotates that quickly, the cam lobe is quite long , the amount of ink it pushes is determined by the length of pipe that isnt compressed.The cams are not pointy like in a car engine where you are looking fdor a short sharp lift. |
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Post by Roger on Dec 28, 2018 13:46:59 GMT
I can see experimenting with a few 3D printed vacuum attachments that shroud the nose of the spindle. You can dream up all sorts of long bristled curtains that surround the work too, but that makes it hard to see what's going on. I like the idea of just an occasional turning on of the vacuum, that might work ok, but it's still noisy. In the end, I'll probably end up living with the swarf on the job. It's easy to get paranoid about keeping the area clean so it doesn't keep ingesting and re-cutting swarf, but for roughing, that's really not important. If you clean up before finishing, the last pass produces very little swarf and I've not found that to be an issue. In the case of a printer the ink is squeezed along a narrow bore plastic pipe in a pumping fashion , it is a sort of pump rather than just a metering device, I dont think the cam rotates that quickly, the cam lobe is quite long , the amount of ink it pushes is determined by the length of pipe that isnt compressed.The cams are not pointy like in a car engine where you are looking fdor a short sharp lift. Ah, I see. I like the idea of a small diameter pipe providing the delivery, you don't need to deliver much oil at speed into a small tube to cause it to be propelled out of the end and onto the work some distance away. I think this is the way forward because otherwise it's just going to dribble out of the tube. |
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pault
Elder Statesman
Posts: 1,502
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Post by pault on Dec 28, 2018 19:33:01 GMT
Regarding drawhooks
Looking back at my dynocar results the highest drawbar pull was about 146 lbs. This was the pull (not snatch) of a slightly over scale 7 1/4" Hall, an engine with a fair bit of grunt. The results of any snatch will depend on how the draw hook is "sprung". Personally I was taught to never use a "scale" coupling. We always used a 3 link steel chain. The only failures I have seen have been caused by derailments where part of the train has stopped dead whilst the rest carried on. The failure was the 2BA thread, not the hook.
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Post by Roger on Dec 28, 2018 22:21:21 GMT
This is how the buffer steps should look on the front...  20140204_112625 by Roger Froud, on Flickr ... and on the back of 1501  DSCN5681 by Roger Froud, on Flickr As you can imagine, these pieces take an awful lot of time with a needle file to get it all to fit and tidy up the edges and nibs. The rear steps don't appear to have a rib on the back to beef them up, but I've added one anyway because they would be a bit flimsy without it. That was Silver Soldered first. This is the second operation, the bracket being retained with Florist's Iron wire to make sure it doesn't come apart when it gets hot.  20181227_220537 by Roger Froud, on Flickr This is how they look when cleaned up.  20181228_110624 by Roger Froud, on Flickr This is the front bracket with the top bend being formed where it attaches to the underside of the buffer gusset casting. I need to add those holes soon.  20181228_145023 by Roger Froud, on Flickr The front bracket is narrower than the rear one, hence the rib on full size. I make the lugs 0.2mm longer than the material thickness.  20181228_150410 by Roger Froud, on Flickr I still like this method of Silver Soldering. I also have started wiping down everything I weld or Silver Solder with 99% pure Acetone which removes all of the oily deposits. I'm only adding Silver Solder wire to one side, it finds its way through the joint easily and it's enough.  20181228_151249 by Roger Froud, on Flickr Everything is plastered with a thin mixture of flux to stop it going black. I use a Titanium pointy stick to move the Silver Solder wire back into position if the flux bubbling moves it. That often happens. What I find is that the lake of flux melts and submerges the wire, preventing it from melting prematurely.  20181228_151741 by Roger Froud, on Flickr The front one went well, the back one didn't form a fillet in the middle....  20181228_160543 by Roger Froud, on Flickr ... So here it is with a little more wire resting in the problem area ready for heating up again.  20181228_161121 by Roger Froud, on Flickr The Silver Solder finds its way into all the nooks by capillary action, you can make the joints as tight as you like.  20181228_161403 by Roger Froud, on Flickr  20181228_165523 by Roger Froud, on Flickr The steps are persuaded around little formers which have a couple of pins to locate in the fixing holes in the blank.  20181228_175933 by Roger Froud, on Flickr  20181228_180230 by Roger Froud, on Flickr All folded, so now they need Silver Soldering...  20181228_200931 by Roger Froud, on Flickr ... I'm adding 'U' shaped pieces of Silver Solder hooked over the corners...  20181228_202658 by Roger Froud, on Flickr ... then flooding with flux and heating each one individually. I don't find doing thing like this is bulk heating works. The tendency is for the heating to be prolonged and they end up getting overheated and black where the flux gives up. Three of them didn't quite bridge the corner, so I added loads more flux, rested a piece of wire in the corner and heated them up again with them using gravity to encourage the flow in the right place.  20181228_211813 by Roger Froud, on Flickr The steps need a little more tidying up, but other than that, they're finished. Some of the steps are riveted, some are bolted. I'm sure there's a reason for this, although it's not obvious to me.  20181228_214444 by Roger Froud, on Flickr |
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,990
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Post by JonL on Dec 28, 2018 23:26:01 GMT
They look the part Roger, nice work.
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Post by delaplume on Dec 29, 2018 2:54:22 GMT
Hi Roger,
There's something quite satisfying about this type of work, isn't there ??
Just for the record, what Flux and rods are you using here ??
Alan..
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Post by delaplume on Dec 29, 2018 3:19:09 GMT
Quote}--- "Some of the steps are riveted, some are bolted. I'm sure there's a reason for this, although it's not obvious to me." Go back to the "Toolbox" photo.........The hex-headed bolts have brackets behind the step's vertical plate whereas the rivets are "stand-alone" as it were....... Note}-- On the injector overflow pipe is a Q/D scroll.........This was added by the SVR staff to facilitate pumping water into the boiler when cold..( Boiler washout for example ).. Anyone Model Engineer with a GWR type safety valve ( ie NON-screw in ) will have this problem as we tend to empty our boilers completely at the end of a running day--- then re-fill at the next lighting-up session......True, you could use the emergency hand pump, but that does tend to take it's time and you run the real risk of developing severe cramps !! For my Mogul I'm using an electric pump discharging into the feedwater snap connector as shown here...  |
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Post by Roger on Dec 29, 2018 8:24:23 GMT
Hi Roger, There's something quite satisfying about this type of work, isn't there ?? Just for the record, what Flux and rods are you using here ?? Alan.. Hi Alan, Yes, I'm warming to this sort of work now I've figured out a way that works through trial and lots of error. I'm using the thin 0.5mm wire sold my Macc Models on eBay in 6 foot lengths, I find that ideal for forming and nestling into the corners I'm trying to Silver Solder. The flux is a fairly runny mix of Easy-Flo which has a dab of washing up liquid in it. I used to mix it thicker, but that disturbs the wire more and only ends up with more on the job than is needed. I generally warm it until it's white and stops bubbling and then get it up to temperature quickly. The advantage of placing the wire like this is you know how much you've added and you don't have to get it anywhere near as hot. |
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Post by Rob on Dec 29, 2018 11:39:10 GMT
The steps need a little more tidying up, but other than that, they're finished. Some of the steps are riveted, some are bolted. I'm sure there's a reason for this, although it's not obvious to me. I think it may be something to do with when they were made. If you look at pictures of the few 15xx that were used by the NCB you'll see that almost all of them had those front and rear steps bent extensively. Some of the pictures have the rear set on the outside of the buffer beam. In lots of pictures they're removed altogether. When they were added back - it's much simpler to use bolts. The following image shows both the bent steps and the rear steps repositioned on 1502 and is by David Cooke on Flickr - www.flickr.com/photos/60790501@N04/5676112798. I'm trying to embed it using the direct link as the usual sharing link doesn't appear to be available. Flickr may detect this and stop the link, so if the picture is missing below that'll be why.  |
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Post by Roger on Dec 29, 2018 22:54:12 GMT
Quote}--- "Some of the steps are riveted, some are bolted. I'm sure there's a reason for this, although it's not obvious to me." Go back to the "Toolbox" photo.........The hex-headed bolts have brackets behind the step's vertical plate whereas the rivets are "stand-alone" as it were....... Note}-- On the injector overflow pipe is a Q/D scroll.........This was added by the SVR staff to facilitate pumping water into the boiler when cold..( Boiler washout for example ).. Anyone Model Engineer with a GWR type safety valve ( ie NON-screw in ) will have this problem as we tend to empty our boilers completely at the end of a running day--- then re-fill at the next lighting-up session......True, you could use the emergency hand pump, but that does tend to take it's time and you run the real risk of developing severe cramps !! For my Mogul I'm using an electric pump discharging into the feedwater snap connector as shown here... Hi Alan, Sorry, I didn't quite make the point clear about the steps with bolts/rivets. I can see what you mean about the ones on the cab side steps, but it was the front buffer steps that I was thinking about. Those have bolts and I can't see why they should have since they don't need removing. I've bought a little pump, similar to the one in your picture for filling the boiler. I could do the same as you say they do on the SVR with the injector overflow, or use the cunning arrangement I'm proposing for using the axle pump to draw water from the driving truck. If I opened the proposed 3-way valve on the inlet to the axle pump so it was only taking water from the driving truck, I could close the bypass valve and that would give a direct route through the axle pump valves to the boiler from the driving truck. I'd have to connect the pump in the line from the driving truck of course. |
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Post by Roger on Dec 29, 2018 22:58:33 GMT
The steps need a little more tidying up, but other than that, they're finished. Some of the steps are riveted, some are bolted. I'm sure there's a reason for this, although it's not obvious to me. I think it may be something to do with when they were made. If you look at pictures of the few 15xx that were used by the NCB you'll see that almost all of them had those front and rear steps bent extensively. Some of the pictures have the rear set on the outside of the buffer beam. In lots of pictures they're removed altogether. When they were added back - it's much simpler to use bolts. The following image shows both the bent steps and the rear steps repositioned on 1502 and is by David Cooke on Flickr - www.flickr.com/photos/60790501@N04/5676112798. I'm trying to embed it using the direct link as the usual sharing link doesn't appear to be available. Flickr may detect this and stop the link, so if the picture is missing below that'll be why. Hi Rob, I think you've probably hit it on the head. Those front steps have taken a hell of a beating! I'm wondering if it might be a smart move to do the same on the rear ones because they're quite likely to get damaged on mine too!. |
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Gary L
Elder Statesman
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Post by Gary L on Dec 30, 2018 1:56:28 GMT
Hi Julian Indeed; everything you say is correct. I wanted to confine the exposition to the pannier tanks, because that is the (oblique) line of descent for the 15xxs. I think your introduction of the 56xx into the discussion does in fact answer completely Roger's point about fitting large engines between the frames. I doubt if anything more powerful than the 56xx was needed, so the 'bits' were readily available to do it, but by 1944 Hawksworth had realised there was no future in perpetuating inside cylinders in the conditions then prevailing, and the 15xx was a quick way of demonstrating this. [Snip] It is the lack of any real need for the 15xx that makes me feel so certain that Hawksworth had other ends in mind for the expensive new components that went into them. I've mentioned the Dukedogs already as one possible target for replacement by a modern outside-cylindered design. Perhaps even more likely was the 45xx and 55xx prairie tanks, some of which dated back to the early 1900s. These also employed the composite cylinder/saddle plus extension frames that Hawksworth disliked so much, but they were also somewhat non-standard, because their outside cylinder castings were smaller than the rest of the Churchward 'standards'. They were nonetheless useful engines, and a redesign (or rebuild) of them along the lines of the 'modified Halls' using 15xx cylinders would make perfect engineering sense, if Nationalisation had not happened. And at the time of laying out the 15xx remember, Nationalisation was not even a distant prospect. It is notable that the Nationalised railway soon set about building its own standard classes, and at the bottom end of the range were a number of classes that could just have easily been built with 15xx cylinders and major components; so a perceived need definitely existed for this kind of development. [Snip] Hi folks I'm quoting myself, and this discussion goes back a few weeks, but you might be interested in some evidence that has come to light to back up the speculation. It appears in the pages of Great Western Steam by WA Tuplin, 2nd Impression dated 1967. Dr Tuplin is discussing some designs that were outlined by the Swindon D.O. but never progressed further for one reason or another; the lower two sketches emanate from the Hawksworth period, and lo and behold, both feature the 15xx cylinders and motion! The pannier tank is particularly interesting, because the longer wheelbase and the addition of the pony truck would have removed the 15xx's nose-heaviness and made it a considerably better proposition on the road, at least in forward gear. Whether it would be completely suitable for the duties being undertaken by the 45xx, lacking a trailing pony truck is more doubtful. Add another pony truck and you would have a 'modernised' 45xx. The only reference to these designs in the book is the highlighted paragraph on the very last page, where Tuplin indicates that the 4-4-0 tender engine could be best explained as a future Dukedog replacement. The axle weights may have proved problematic, but it would certainly have been an easier locomotive to service and maintain. A 2-6-0 derivative would have been easy to visualise, as Tuplin hints, and might have been thought of as an improved (or rebuilt) 'Manor.' At this time, the Manors had not received their improved drafting and were considered to have an inadequate (and one-off) boiler for their large cylinders; not an entirely satisfactory replacement for the Moguls they were 'rebuilt' from. 1944 also happens to be the year that the the 15xx project was first sketched out, and the year that the Modified Halls made their appearance, with the first County the year after. It is not too fanciful to imagine Hawksworth planning out a future motive power programme in the same way Churchward had done forty years earlier, a programme in which the young Hawksworth took part. Unfortunately he did not share Churchward's gift of foresight, particularly the impact of dieselisation on these smaller classes, which is surprising considering the success of the hundreds of diesel shunters that were already operating on the LMS. Unlike his celebrated former chief, Hawksworth did not have the prospect of 20 years in post ahead of him, so these developments would mostly fall to his successor, as he would have seen it. So there we have it, I think. The 15xx was not an aberrant one-off, but is more correctly seen as the forerunner and sole survivor of a wider programme that never went any further. Maybe it would have done if Nationalisation had not taken place three years later? Gary   |
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Post by Roger on Dec 30, 2018 6:50:19 GMT
Hi Gary,
Thanks for pulling out that research, it certainly makes good sense, and those two outlines certainly seem to have the very distinctive 'gear frame' and the drop link from the crosshead like 1501 has with what's obviously Walschaerts valve gear.
It does seem to show a remarkable lack of foresight to have even embarked on the 15xx design, but I suppose they did at least manage to use an existing boiler.
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Gary L
Elder Statesman
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Post by Gary L on Dec 30, 2018 9:17:13 GMT
Hi Gary, Thanks for pulling out that research, it certainly makes good sense, and those two outlines certainly seem to have the very distinctive 'gear frame' and the drop link from the crosshead like 1501 has with what's obviously Walschaerts valve gear. It does seem to show a remarkable lack of foresight to have even embarked on the 15xx design, but I suppose they did at least manage to use an existing boiler. Yes indeed. But I hadn't noticed the blindingly obvious point about the proposed 2-6-0PT, which is the reversion to a parallel boiler with steam dome. In 1944 the shortcomings of the 94xx pannier tank for shunting, due to the high and wide taper boiler backhead was already known, and yet the 15xx, an explicitly shunting engine, was drawn out with the same defect. In this sketch from the very same year we see a different, new, non-standard boiler being proposed, presumably to address this issue. Perhaps boiler proliferation is the main reason why the 2-6-0PT was never proceeded with? We will never know. -Gary |
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mbrown
Elder Statesman
Posts: 1,793
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Post by mbrown on Dec 30, 2018 13:04:00 GMT
To be honest, I take Dr Tuplin with a fairly large pinch of salt, although he is a highly entertaining and original writer. Many of his books show projected designs in the style various companies, but the evidence that they were ever seriously contemplated in the form he shows them tends to be thin. Many ideas would be "contemplated" in a drawing office and then rejected pretty quickly on pragmatic grounds.
I suspect that Tuplin had picked up some hints that (e.g.) an outside cylinder 2-6-0T had been considered (possibly by someone very junior) and then drew it up from his own ideas. I would be very dubious that Swindon ever gave serious consideration to a loco of that form which would have had very different properties as a vehicle when running forward and in reverse. I believe weight distribution questions killed off many bright ideas before they had got very far, and I suspect the outside cylinder 4-4-0 would have hit problems in terms of the equation between weight distribution, hauling power and clearances for the cylinders - all factors which had to be worked in at the beginning.
Tuplin's drawings of unbuilt locos are always imaginative, but he seems to have given little or no thought to questions of weight or even, in some cases, practicability, like his projected update of the LNWR Prince of Wales where the cab would be an ergonomic disaster.
Holcroft and Cox show a number of projected LMS designs which were worked up at conceptual level in the drawing office - including several updated versions of the Derby 4F - but it is clear that a great deal more thought had gone into these than into Tuplin's designs and the final decision not to build was often more about economics than engineering.
Of course, none of my comments help with the genealogy of the 15XXs, so I'd better shut up!
But where Tuplin excels is in his imaginative recreations of footplate work on long-gone classes of loco!
Malcolm
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barlowworks
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Now finished my other projects, Britannia here I come
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Post by barlowworks on Dec 30, 2018 18:26:15 GMT
Hi Roger
Could the front steps be bolted on for easy removal if the piston requires removing during a service.
Mike
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Post by Roger on Dec 30, 2018 19:41:00 GMT
Hi Roger Could the front steps be bolted on for easy removal if the piston requires removing during a service. Mike Hi Mike, The whole front step arrangement is bolted to the underside of the buffer gusset, so it can easily be removed if necessary. I think Rob is right about the individual steps being bolted on so it's easier to straighten up and repair when it gets mangled like both sides are in the photo he posted. |
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