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Post by delaplume on Sept 29, 2019 22:06:48 GMT
if you arrange the filter so the water flows from outside to inside, it is easy to clean by putting an airline on the inside and giving it a blow That's the way I pictured it being fitted. Yes, that will certainly be easy to clean that way. That's generally the accepted direction of flow because the outer surface has the greater captive area.......
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Post by Deleted on Sept 29, 2019 22:31:44 GMT
Hi Roger
Can I make a couple of observations please. Looking at you arch I'm not so sure if it's a good idea to have the gaps either side, in my mind this will cause gases to be funnelled up through these gaps which I suspect will be hotter than normal that close to the firebox sides. The other point is the arch isn't really an 'arch', it's more 'box' like with it's flat roof. An arch makes more sense to me, I can imagine how the gases are drawn up under the arch and over the top with an even heat as in general the underside if the arch is equaldistant from the firebed. This perhaps wouldn't be the case with a flat roof? Hope that makes sense...
Cheers
Pete
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Post by Roger on Sept 29, 2019 22:46:21 GMT
Hi Roger Can I make a couple of observations please. Looking at you arch I'm not so sure if it's a good idea to have the gaps either side, in my mind this will cause gases to be funnelled up through these gaps which I suspect will be hotter than normal that close to the firebox sides. The other point is the arch isn't really an 'arch', it's more 'box' like with it's flat roof. An arch makes more sense to me, I can imagine how the gases are drawn up under the arch and over the top with an even heat as in general the underside if the arch is equaldistant from the firebed. This perhaps wouldn't be the case with a flat roof? Hope that makes sense... Cheers Pete Hi Pete, Those areas are where I described as being filled with 'ears'. I'm not sure how the flow will go at that point, it might be that such an extreme reversal of flow doesn't happen and not much goes around there. I'm going to have a look and see how hard it would be to remove the arch if I added something there. Anything wider than what's already there is going to have to be turned at an angle to get it out. Personally I don't think the shape of the arch is really that important. What you're trying to do is to force the gasses to the back. Allowing the gasses in the middle to be slightly higher doesn't seem to me to have much advantage, but it's more difficult to make. The flow in the middle is almost certainly going to be greater than the flow at the outside whatever you do. To be honest, it's all complete guesswork! Until it's tried and I can watch what's happening it's going to be a mystery.
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Post by steamer5 on Sept 29, 2019 23:01:32 GMT
Hi Roger, Thanks for the reply, re ball squeeze, it looks like I’ll just have to try it & see!
Re your arch, with the latest photos of its install I agree with Julian, you are providing a shield for the front & part of the sides of the fire box, which is were you get the most heat available to heat the water. The only suggestion I can make is to remove most of the vertical plate, leaving only a frame to support the upper section, which isn’t likely to last long!
On the heat front I had an interesting discussion with a gent on how hot does the front tube plate get just above the fire...........not as hot as I thought it turns out! They had the blower full on & a good fire, using a laser thermometer the plate was in the region of 250 to 280 C.....which is logical if you think about it as the other side of the plate has water which is pull the heat away.
Another source of filters is replacement filters for washing machines.....they are a bit courser than the one you show which would be less restriction.
Cheer Kerrin
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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: 961
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Post by don9f on Sept 29, 2019 23:04:25 GMT
The “arch” in a full size firebox obviously has to be self supporting....hence its shape. There are usually a number of protrusions or pegs on the firebox sides at the appropriate height above the grate, for the arch to rest on, or should it be “spring from”? Many these days are actually built in refractory concrete.
I think you should carry on Roger, and see how it steams once it’s a runner!
Cheers Don
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Post by chris vine on Sept 30, 2019 1:21:52 GMT
Hi Roger,
This is the first time I have said this during your build, but I am not sure I like your stainless "arch". When I made a stainless arch for Bongo, i just made a bent piece of (thick) stainless which bolted into a couple of specially large stays at the bottom of the throat plate. It goes up a little and then angles back (like yours) However, I just shaped it by trial and error, (with cardboard) until its widening shape fitted the internal shape of the firebox. Including a few recesses to clear stay ends.
It has lasted for years, including running gently at exhibitions for 8 hour stretches for days on end. Also some fairly hard running for short bursts. I made a couple of spares at the time as I could just scribe round the original. But they are still in the box!
Maybe your cad model will give you an almost perfect development of the shape. You could leave it 1 mm big on the sides and then trim/fit to suit.
Keep up your novel ideas, it will be a cracker of an engine!
Chris.
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Post by Roger on Sept 30, 2019 6:54:32 GMT
Hi Roger, Thanks for the reply, re ball squeeze, it looks like I’ll just have to try it & see! Re your arch, with the latest photos of its install I agree with Julian, you are providing a shield for the front & part of the sides of the fire box, which is were you get the most heat available to heat the water. The only suggestion I can make is to remove most of the vertical plate, leaving only a frame to support the upper section, which isn’t likely to last long! On the heat front I had an interesting discussion with a gent on how hot does the front tube plate get just above the fire...........not as hot as I thought it turns out! They had the blower full on & a good fire, using a laser thermometer the plate was in the region of 250 to 280 C.....which is logical if you think about it as the other side of the plate has water which is pull the heat away. Another source of filters is replacement filters for washing machines.....they are a bit courser than the one you show which would be less restriction. Cheer Kerrin Hi Kerrin, It's certainly possible to remove a lot of that material that's in front of the throat plate, and that may well be what I do. I'm tempted to leave it for the time being though, just to see what happens! It's very easy to take out and try a lot of different arrangements, so it will be interesting to see the effect of any changes. My guess is that it will make less of a difference than you might imagine. That plate will have the fire laying against it, so it's pretty likely that it will be extremely hot. Some of that heat will surely transfer to the throatplate, it would be impossible to stop it.
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Post by Roger on Sept 30, 2019 6:59:23 GMT
Hi Roger, This is the first time I have said this during your build, but I am not sure I like your stainless "arch". When I made a stainless arch for Bongo, i just made a bent piece of (thick) stainless which bolted into a couple of specially large stays at the bottom of the throat plate. It goes up a little and then angles back (like yours) However, I just shaped it by trial and error, (with cardboard) until its widening shape fitted the internal shape of the firebox. Including a few recesses to clear stay ends. It has lasted for years, including running gently at exhibitions for 8 hour stretches for days on end. Also some fairly hard running for short bursts. I made a couple of spares at the time as I could just scribe round the original. But they are still in the box! Maybe your cad model will give you an almost perfect development of the shape. You could leave it 1 mm big on the sides and then trim/fit to suit. Keep up your novel ideas, it will be a cracker of an engine! Chris. Hi Chris, I feel a number of different patterns coming on, there's a huge variety of possible arch shapes and sizes to try. I don't think the shape is as critical as one might imagine, I think it's more about how far back the gasses have to go to get around it. I reckon you could make it almost any shape and it would have the same effect. Time will tell, it's all part of the fun of trying something new.
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Post by dhamblin on Sept 30, 2019 7:35:48 GMT
Could you assemble the boiler plus superheaters and smokebox, then use 'smoke in a can' and test it with the blower to see the flow of air? Use a cheap endoscope camera through the firehole to see over the arch / shield.
You could even set it up with the rosebud grate and see the effect it has. You'll probably need a good shroud to make sure the smoke goes up through the grate when released.
Regards,
Dan
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uuu
Elder Statesman
your message here...
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Post by uuu on Sept 30, 2019 7:49:33 GMT
Please no! All this theorising and conjecture is doing my head in. Get it finished and stick a proper fire in it. Then you can ride round smug (or glum) and tell us how it went.
Wilf
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Post by Roger on Sept 30, 2019 8:13:09 GMT
Could you assemble the boiler plus superheaters and smokebox, then use 'smoke in a can' and test it with the blower to see the flow of air? Use a cheap endoscope camera through the firehole to see over the arch / shield. You could even set it up with the rosebud grate and see the effect it has. You'll probably need a good shroud to make sure the smoke goes up through the grate when released. Regards, Dan Now there's an interesting idea, it's certainly one way to see what effect and arch might have.
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Post by Roger on Sept 30, 2019 8:15:42 GMT
Please no! All this theorising and conjecture is doing my head in. Get it finished and stick a proper fire in it. Then you can ride round smug (or glum) and tell us how it went. Wilf Hi Wilf, Exactly, I'm definitely a fan of cracking on and trying it. It's hard to see how it won't work as a steam locomotive, it's just a matter of how well. When you look at how crude some locomotives are and how well some of them run, you could argue that all these nuances are just window dressing.
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Post by simplyloco on Sept 30, 2019 8:44:35 GMT
Please no! All this theorising and conjecture is doing my head in. Get it finished and stick a proper fire in it. Then you can ride round smug (or glum) and tell us how it went. Wilf Hi Wilf, Exactly, I'm definitely a fan of cracking on and trying it. It's hard to see how it won't work as a steam locomotive, it's just a matter of how well. When you look at how crude some locomotives are and how well some of them run, you could argue that all these nuances are just window dressing. Agreed! I can imagine LBSC starting to spin already...
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Sept 30, 2019 9:14:16 GMT
Could I mention that the greatest innovator in the steam world was André Chapelon thus his work is worth a study before tossing cans of smoke into your firebox unless of course you are on the main line and being photographed! D
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Post by delaplume on Sept 30, 2019 9:41:16 GMT
Could I mention that the greatest innovator in the steam world was André Chapelon thus his work is worth a study before tossing cans of smoke into your firebox unless of course you are on the main line and being photographed! D Quite right too !!---------- I'm actually in full agreement with you on this one..........For example}--The standard GWR loco. bogie that came out of Swindon was actually a De Glehn design initially............and a lot was learnt by Churchward after the purchase of the French locos and subsequent use on home metals... I would ask that Roger heed the tried and tested maxim when it comes to R & D work and that is to "implement one change at a time" in order to identify exactly what effect ( if any ) that change has had ???
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Post by delaplume on Sept 30, 2019 9:48:40 GMT
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Post by Roger on Sept 30, 2019 10:19:26 GMT
Could I mention that the greatest innovator in the steam world was André Chapelon thus his work is worth a study before tossing cans of smoke into your firebox unless of course you are on the main line and being photographed! D Quite right too !!---------- I'm actually in full agreement with you on this one..........For example}--The standard GWR loco. bogie that came out of Swindon was actually a De Glehn design initially............and a lot was learnt by Churchward after the purchase of the French locos and subsequent use on home metals... I would ask that Roger heed the tried and tested maxim when it comes to R & D work and that is to "implement one change at a time" in order to identify exactly what effect ( if any ) that change has had Oh yes, one change at a time, but from whatever starting point that happens to be. I can't really take the SPEEDY design and change one small thing after another. Some things just have to be implemented from the start, such as the number and size of boiler tubes, Superheaters, cylinder diameter etc. Yes, I could start with a conventional grate and then switch to a Rosebud one, but I'm more inclined to go for Gold in one hit and then experiment when things aren't as good as expected... one change at a time.
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Sept 30, 2019 18:48:45 GMT
Roger I got on the rosebud thing and made one for my PoW. The fire burnt as before. Chucked it as there semed no point in fixing something that weren't broke, after all we are not using lignite from the Rosebud mine we are using good coal. Why drink champagne from paper cups when the crystal is on the shelf? David
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Post by Roger on Sept 30, 2019 19:22:10 GMT
Roger I got on the rosebud thing and made one for my PoW. The fire burnt as before. Chucked it as there semed no point in fixing something that weren't broke, after all we are not using lignite from the Rosebud mine we are using good coal. Why drink champagne from paper cups when the crystal is on the shelf? David Hi David, Fair enough, but I didn't have a grate to begin with. There are so many variables, such as the gap around the grate and the hole to metal ratio that you can play with. I doubt if two people have the same experience with them! Don't let's forget that no two grate arrangements are the same either. Some have wider gaps, thinner or thicker bars etc, so you might find you get a different experience with a different conventional one. In the end, if it works really well then I don't see that it matters much what the grate looks like. For me, it's much easier to make a Rosbud grate than a conventional one, so it makes sense to do it that way. It's also possible to change the diameter of the holes in different areas of the grate, something you can't do with a conventional one. It's all good fun, and experimenting is going to be interesting!
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Post by Roger on Sept 30, 2019 19:32:38 GMT
The job today is this inline water filter... Water filter assembly by Timothy Froud, on Flickr ... this being the body section getting its thread for the M8 x 0.75 (fine) Union 20190930_102500 by Timothy Froud, on Flickr Turning it round, it's now got a 13mm hole for the M14 x 1 (fine) thread and also an 1/8" BSPP thread for the filter. 20190930_111025 by Timothy Froud, on Flickr This is the end cap which needs to have a hex and union thread on the end in my hand. I didn't have an M14 x 1 (fine) fixture, so I made one first. 20190930_150647 by Timothy Froud, on Flickr The threaded part was firmly screwed into it by holding the body in the oversized drill chuck that goes up to 16mm 20190930_150753 by Timothy Froud, on Flickr The union thread was then added... 20190930_153732 by Timothy Froud, on Flickr ... before moving on to the mill for the hex to be machined. I have to take this gently, 0.5mm deep cuts at a time, because it might unscrew from the fixture if I'm heavy handed! 20190930_154017 by Timothy Froud, on Flickr 20190930_164542 by Timothy Froud, on Flickr Returning that to the lathe, the chamfer on the hex could be finished. 20190930_164847 by Timothy Froud, on Flickr So here are all the bits and pieces... 20190930_200830 by Timothy Froud, on Flickr 20190930_200934 by Timothy Froud, on Flickr It's pretty compact. The idea is to fit this in the pipe that comes from the riding truck. There's a slight resistance to flow through the sintered element, so hopefully that will stop any tendency for the flow to reverse. 20190930_200945 by Timothy Froud, on Flickr
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