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Post by Roger on Sept 19, 2018 23:02:36 GMT
This now begs the question - has anyone tried angling the outside 2 rows of holes toward the outside, thus improving the heat transfer to the firebox sides? Eddie. Hi Eddie, An interesting thought. My guess is that it wouldn't make much difference. I think the gap around the edge probably has much more influence than that would have. |
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Post by Cro on Sept 20, 2018 5:15:41 GMT
Roger were you drilling all the holes the same size? I was under the impression that there was a mix of sizes between centre and outer edges with the inside holes small that the outer ones as air flowed easier through the centre? I may be wrong but this was my understanding and I way try it in the 9f but it's not easy to change if it doesn't work.
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Post by 92220 on Sept 20, 2018 8:08:11 GMT
Hi Adam.
One point to bear in mind when trying a rosebud in the 9f: the grate is angled in the middle so air will be 'jetted' out of the holes and in the upper vicinity of the fold in the grate, you are likely to get a large void where there is no air flow. I'm not sure how that void area could be got over. Hope that all makes sense, and just a thought.
Bob.
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Post by Cro on Sept 20, 2018 8:21:32 GMT
It's a good point Bob, the issue I found with the 9f in the year/18months of steaming was the back of the grate was very hard to light with a huge lack of air flow so I am considering options to improve this. It is very shallow under the door and lack of space under the grate. Thinning the bars top and bottom at the back is my first step to increase area above and below.
Adam
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Post by Roger on Sept 20, 2018 8:22:02 GMT
Roger were you drilling all the holes the same size? I was under the impression that there was a mix of sizes between centre and outer edges with the inside holes small that the outer ones as air flowed easier through the centre? I may be wrong but this was my understanding and I way try it in the 9f but it's not easy to change if it doesn't work. Hi Adam, I don't think it's wise to try to second guess what might be necessary before it's been tried. I would want to see how the edges burn before opening them out. It may be that the air passing around the grate makes that unnecessary. |
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Post by Cro on Sept 20, 2018 10:32:11 GMT
Totally understand I've just seen a few and this was the impression I got from seeing them. I see another test fixture coming on! ;-)
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stevep
Elder Statesman
Posts: 1,073
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Post by stevep on Sept 20, 2018 13:57:26 GMT
For what it's worth, my understanding of the 'fluid bed' effect is that the fire is actually held away from the grate itself.
That said, my grate is made from 1/4" mild steel, and is not showing signs of distress. So if one wanted to experiment with different/varying sized or angled holes, it's not actually difficult to make several with different parameters.
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Post by Roger on Sept 20, 2018 14:51:18 GMT
For what it's worth, my understanding of the 'fluid bed' effect is that the fire is actually held away from the grate itself. That said, my grate is made from 1/4" mild steel, and is not showing signs of distress. So if one wanted to experiment with different/varying sized or angled holes, it's not actually difficult to make several with different parameters. Hi Steve, I'd have to see that fire being raised for myself, it sounds fanciful of me if I'm being honest. I'm more inclined to think that the local burning around the hole is very intense, and that's probably the key to this working. I'm making the grate from Stainless Steel which does pose significant problems. Maybe it's better to make one from Mild Steel first to prove the design before going down that route. |
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uuu
Elder Statesman
your message here...
Posts: 2,860
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Post by uuu on Sept 20, 2018 16:54:41 GMT
John the Pump has been welding up an ash-pan at the Pumphouse (not for me), with a ledge around the side. This holds the grate up, but has the secondary property of blocking air from coming around the sides. Even though my grate pivots, it may be possible to arrange a ledge above on one part, and below on another.
Wilf
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Post by steamer5 on Sept 20, 2018 17:25:56 GMT
Hi guys, Here’s a link that shows what’s happening..... youtu.be/VQJIoHUj2VIThere has also been a series in the Australian Model Engineering mag on them. From memory it has lots of useful info in it that covers some of the questions being asked / talked about. Cheers Kerrin |
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Post by Roger on Sept 20, 2018 18:07:47 GMT
Hi guys, Here’s a link that shows what’s happening..... youtu.be/VQJIoHUj2VIThere has also been a series in the Australian Model Engineering mag on them. From memory it has lots of useful info in it that covers some of the questions being asked / talked about. Cheers Kerrin Thanks for that Kerrin, I'm sure I've seen that before. I don't see any sign of that 'fluid bed', the lumps of coal seem to stay where they were put. When it's flat out, there are sparks everywhere, but that's probably what happens on any fire. You can see the extremely hot points where the holes are though. It's a very interesting video. |
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Post by Roger on Sept 20, 2018 21:37:41 GMT
This is the corner piece of the backhead cladding that needs to be screwed to the part I had to cut off. I was going to Soft Solder this because I thought it might melt the thin edges of the Brass sheet if I Silver Soldered it. Then I thought sod it, I'll give it a try with Silver Solder because it would be much stronger.  20180920_154303 by Roger Froud, on Flickr Fortunately that worked out well.  20180920_160559 by Roger Froud, on Flickr Although I showed the brake valve nicely vertical in an earlier post, the reality was that when it was tightened fully, it was several degrees too far clockwise. This is despite it being spot on before the boiler was Silver Soldered. The conclusion is that there's always going to be some movement in these things and you can't create a perfect fit unless you leave a little material on the fitting's flange and trim that to suit the finished boiler. Lesson learned, but what to do about the fitting I've made and would rather not have to make again? So this is my solution, ie to sweat some Lead Free solder onto the flange. This is easier said than done, it's not the easiest solder to wet the surface with. I first used the recommended flux I have for PCB work, but that catches fire. I then tried a flux suitable for Comsol and that worked much better. Even so, it really didn't want to wet the whole surface.  20180920_195810 by Roger Froud, on Flickr By the time it had covered enough of the surface, it had also partially filled the 'O' ring groove.... bugger! Still, there's enough on there to machine back and get a large enough surface to get a solid bite when the fitting is tightened.  20180920_201348 by Roger Froud, on Flickr This is how far out it was before any machining.  20180920_211309 by Roger Froud, on Flickr I found the stub mandrel that I made to machine the part in the first place and clocked it up in the 4-jaw so I could clean it up...  20180920_204902 by Roger Froud, on Flickr ... and this is the initial clean up...  20180920_211059 by Roger Froud, on Flickr ... which brought it a lot closer. 20180920_211309 by Roger Froud, on Flickr I very tentatively trimmed it 20microns at a time until it ended up nice and tight and in this position which I'm very happy about. I did wonder how soft it would feel as it bottomed onto the flange, and was surprised to feel that it's not soft at all. I guess the area is pretty large and the solder is pretty hard. Lead free PCB solder is horrible to use compared to the old 60/40 lead stuff, but it's a lot stronger. I'm really liking the patina that heating the fitting has given it, that's an awful lot closer to how it looks on 1501. I won't be cleaning that up.  20180920_215049 by Roger Froud, on Flickr |
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dscott
Elder Statesman
Posts: 2,440
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Post by dscott on Sept 21, 2018 0:58:04 GMT
Yes for some pattena I got my Cousin to handle parts he adds a special sweat to metals
and they look very old and authentic overnight. Some modern car paints do the same with some
people!! simon 48 if you are interested!!
I do love the plug housings these make the piece perfect!!
David and Lily.
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Post by Roger on Sept 21, 2018 7:36:56 GMT
Yes for some pattena I got my Cousin to handle parts he adds a special sweat to metals and they look very old and authentic overnight. Some modern car paints do the same with some people!! simon 48 if you are interested!! I do love the plug housings these make the piece perfect!! David and Lily. Hi David, We used to have someone like that in our workshop, you could see perfect fingerprints on some of the Steel parts he'd handled! I've got one more of those plug pieces to make, and to decide whether it's going to be used as an additional fixing point or not. It's where there's another tapped stay that was originally going to be used to secure the backhead. |
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Post by 92220 on Sept 21, 2018 7:49:35 GMT
Lovely job Roger!!!
Bob.
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Post by Roger on Sept 21, 2018 18:21:50 GMT
Thanks Bob. This is going to be the long pull rod for the drain cocks. It runs between the wheel backs and the frame, so it's pretty slender. This is a 500mm long sheet of Gauge plate 1.5mm thick. I've clocked the back so I can use that as one side of the rod. I can't reach the full length that I need so I thought I might as well just cut a piece off the side over the full length since I've got to move it along anyway. Here I'm using a 2-flute 2.5mm cutter that's pretty worn, but plenty good enough for this job. I'm cutting 0.8mm deep on the first cut and 10mm/min and 700RPM. That seems pretty happy and there's no rush. The second cut is to 1.35mm deep so it stays in place. After the first 0.8mm cut, I measured the width which has deliberately too wide so I could adjust it for a second depth with the right width.  20180921_141255 by Roger Froud, on Flickr Then it was moved along for the rest of it.  20180921_151210 by Roger Froud, on Flickr It broke through on some of the length and in other places it didn't show at all. That's pretty usual with this sort of thing.  20180921_184440 by Roger Froud, on Flickr Anyway, it tidied up nicely with very little filing so that's ready for forming the joggle in the end next  20180921_191029 by Roger Froud, on Flickr |
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dscott
Elder Statesman
Posts: 2,440
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Post by dscott on Sept 21, 2018 23:09:50 GMT
This is one of my cunning plans of doing all the LONG jobs while set up and
going through all similar jobs as we get to them. In an ideal world!
I was given a piece of cast iron heavy angle and cutting it in 2 and adding
holes for bolts gave me a very long vice. Yes the Tee pieces spring to mind.
Meanwhile we get rained off the roof of the garage and you leave just a little
gap and we get flooded out with a damp carpet!! I did the job this afternoon
and of course we have a dry night.
I think Gauge Plate is one of the forgoten materials for fine items that need to
move.
David.
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Post by Roger on Sept 22, 2018 7:08:51 GMT
This is one of my cunning plans of doing all the LONG jobs while set up and going through all similar jobs as we get to them. In an ideal world! I was given a piece of cast iron heavy angle and cutting it in 2 and adding holes for bolts gave me a very long vice. Yes the Tee pieces spring to mind. Meanwhile we get rained off the roof of the garage and you leave just a little gap and we get flooded out with a damp carpet!! I did the job this afternoon and of course we have a dry night. I think Gauge Plate is one of the forgoten materials for fine items that need to move. David. Hi David, I like the idea of a long 'vice', especially if it could be mounted on a base plate with dowels every 50mm or so to let the base plate stay put, while moving the vice along. If I had a lot of long work to do, that's the sort of thing I'd seriously think about making. I think people shy away from Gauge Plate because they imagine it's much more difficult to machine than it really is. It also tends to only be thought of in the context of tooling or things that have to be hardened. It's a really handy material for rod, linkages and handles because it's so much more rigid than the alternatives. I also imagine that most people aren't aware of the wide range of sizes it's available in. |
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Post by simplyloco on Sept 22, 2018 8:10:09 GMT
SNIP I think people shy away from Gauge Plate because they imagine it's much more difficult to machine than it really is. It also tends to only be thought of in the context of tooling or things that have to be hardened. It's a really handy material for rod, linkages and handles because it's so much more rigid than the alternatives. I also imagine that most people aren't aware of the wide range of sizes it's available in. I agree, I've got loads of the stuff here ( a lucky job lot) and it has many uses. In fact, I sent a piece to a poster on here to try out: I didn't get a thank you for my trouble...  John |
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Post by terrier060 on Sept 22, 2018 8:41:31 GMT
I agree - gauge plate is wonderful stuff and cuts better than mild steel in my opinion. I like the way you cut the long piece in several goes. It reminded me of cutting out the Terrier frames. I did them all on the Myford by hand and had to move them three times! Also the BMS was not properly normalised, so the metal kept springing as I cut out the horn slots. I overcame this by cutting out the slots in several goes until there was no more spring! As you know, Terrier frames are very light and more HOLE than metal!
I will be doing the same job as you with my drain cock connecting rod to the cab, which runs under the outside of the left hand running plate, just alongside the angle-iron valance. Like yours it is very slender and long and has bends in it.
Ed
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