Neale
Part of the e-furniture
5" Black 5 just started
Posts: 283 
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Post by Neale on Jan 15, 2021 7:52:47 GMT
My thoughts - take a few thou off the flanging plate and use that to very slightly close up the flange, and/or take a few thou off the flange in the lathe, as long as that leaves sufficient metal to meet the spec. I have to admit that my own boiler-making to date is confined to a 3" vertical boiler but that's a case where you have to get the flange diameter right as it's fitting into a tube whose diameter is non-negotiable!
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Post by ettingtonliam on Jan 15, 2021 8:34:21 GMT
I agree, take about 10 thou off the flanging plate, and use that to reduce the size of the tubeplate.
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Post by gwr14xx on Jan 15, 2021 9:21:47 GMT
You could try tack welding a square block to the back of the flanging plate so that the plate can be held in a 4 jaw chuck (and centred) - then run a ball race against the flange. Squeezing the flange, and ironing out any high spots, may bring the diameter down enough without actually removing any metal!
Eddie.
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Post by simplyloco on Jan 15, 2021 9:41:04 GMT
Roll out the barrel, let's have a barrel of fun. But not quite, not yet. The smokebox end of the barrel is 0.006" undersize and the smokebox tubeplate is 0.015" oversize. The latter maybe improved by judicial tapping of the flange on the smokebox tubeplate to bring it closer to size. The reason for the oversize is that I couldn't remove the steel flanging die if the tubeplate was too tightly peened. To show the affect of this error of dimensions I have pushed the smokebox tubeplate into the end of the barrel and show the amount of gap that will occur at the joining strip if nothing else is done. If the tapping of the smokebox flange doesn't improve matters I could take a few thou' off the smokebox tubeplate diameter or insert a very thin piece of copper to close the gap. Any suggestions? The 1 1/4" joining strip will be on the inside. barrel by Brian Leach, on Flickr barrel1 by Brian Leach, on Flickr barrel2 by Brian Leach, on Flickr The smokebox tubeplate is the scrapped one so a bit of coaxing didn't go amiss. Brian I'm no expert in these matters, but I'd do nothing as I'm confident that your wide overlapping joining strip will take care of that small gap in the boiler joint. Alternatively, if you have a linisher you could shave the tube plate in the right places to make a better fit. John |
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Post by runner42 on Jan 17, 2021 3:40:52 GMT
The BI has OK'd the flange plates, commented on the smokebox tubeplate saying that that it needs some tapping further and/or some skimming to reduce the OD. Apparently he is not concerned by material removal because it is 3 mm thick anyway. But cautioned that it requires a tight fit in the barrel to reduce the amount of silver solder needed.
Brian
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Post by runner42 on Jan 22, 2021 6:19:52 GMT
I needed to produce a former for the outer wrapper. Previously, I used a cut down versions of the outer wrapper former, ie using only three profiles, the backhead end, a middle and the barrel and throat plate end spaced only with scrap timber. But this time I thought it pertinent to produced a full profiled outer wrapper former. I used MDF, which I thought was easy to work so the task would be completed in one day, but it took three days. The sanding was originally done in the shed but the dust covered everything and was probably unwise to undertake the task in a closed environment. So outside became the place of choice, but that fell foul of the wife as the dust drifted on her washing and clung to the crevices in the outside brickwork. I would still be sanding but SWMBO put the hard word on me. It doesn't need to be profiled as if it were aeroplane wing, the ends are important and the in between can be near enough is good enough. A lot of work for a one off use and $30 for the MDF/  outer wrapper former by Brian Leach, on Flickr  outer wrapper former backhead end by Brian Leach, on Flickr  outer wrapper former barrel end by Brian Leach, on Flickr The 16 x 16mm MDF pieces took a lot of cutting, I purchased a jig saw for the purpose. Just the inner wrapper former to make/ Brian |
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Post by runner42 on Jan 24, 2021 5:54:36 GMT
The drawing doesn't appear to specify the number and type of fixings for the steam dome flange, so could a Black 5 builder indicate these details size, number and PCD. I would imagine that fixing studs and nuts would be preferred. Also the blower tube does not run in a straight line and needs a kink in it to clear the inner wrapper (see red line on photo). This is going to be a problem for me so if anyone has an alternate solution using a kinkless method I shall be most appreciative. I have purposely not drilled the holes for the blower tube in the backhead and smokebox tubeplate so some adjustment of the position of the holes could help reduce this interference issue. Brian  boiler blower by Brian Leach, on Flickr |
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Post by RGR 60130 on Jan 24, 2021 10:09:36 GMT
Brian,
Is the dome cover not drawn on another sheet to show the fixings?
Regarding the blower tube, I'd suggest talking to your boiler inspector about moving the bushes up a bit.
Reg
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Post by Deleted on Jan 24, 2021 11:18:54 GMT
Brian, Is the dome cover not drawn on another sheet to show the fixings? Regarding the blower tube, I'd suggest talking to your boiler inspector about moving the bushes up a bit. Reg Don does have a bad habit of spreading drawings out to fit other sheets, or worse still reverding them. I'd be very surprised if the dome cover isn't there somewhere? Regarding blower tube, it doesn't look that big an issue, the tube will sag naturally anyway if fed in from the back. If it touches the crown I would just give it a shallow dogleg to clear...I'm not sure what the implications could be if it's resting on the crown? Leave that one for the experts...  Pete |
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Post by Jim on Jan 24, 2021 11:47:57 GMT
I'd also give some thought to reversing the smoke box tube plate so the flange faced inwards to give you a small recess round the joint caused by the curve of the flange. It would give you a natural point for the silver solder to flow along and ensuring good penetration when brazing up the tube plate.
Jim
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mbrown
Elder Statesman
Posts: 1,790
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Post by mbrown on Jan 24, 2021 13:13:18 GMT
Not sure why a kink in the blower tube is a problem. It's not a stay so is not carrying any load between the front and back of the boiler. One of my boilers has a 1/4" exhaust for the vacuum ejector running through the boiler and it has a major dog leg in it to get around the firebox and crown stays. It took a bit of wangling to get it in but once there I have had no trouble.
Malcolm
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stevep
Elder Statesman
Posts: 1,073
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Post by stevep on Jan 24, 2021 19:49:52 GMT
I thought that blower tubes were often used as a stay. If so, then the straighter the run the better.
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Post by Deleted on Jan 24, 2021 20:03:36 GMT
I thought that blower tubes were often used as a stay. If so, then the straighter the run the better. Not all Steve.. my boiler as of yet doesn't have the blower tube, I'll fit it later, it isn't a stay, just a plain tube.. in fact, my boiler doesn't have any longitudinal stays.. Pete |
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Post by runner42 on Jan 24, 2021 23:05:10 GMT
Brian, Is the dome cover not drawn on another sheet to show the fixings? Regarding the blower tube, I'd suggest talking to your boiler inspector about moving the bushes up a bit. Reg Reg, the dome cover is on the same boiler drawing but as you see doesn't show the number and type of fixings used.  turret by Brian Leach, on Flickr Moving the backhead blower position up a bit will work just, but it will require a flat be cut on both the blower flange and the regulator flange to form a figure 8 configuration. I'll get the BI views on that, it will be a value judgment on part of the BI as the AMBSC Code Part 1 doesn't address such deviations. Brian PS I have just realised that the AMBSC Code Part 1 specifies the size and number of fixings required based on the PCD. For the size of flange of 2 1/2" dia I require at least 12 M5 fixings. |
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Post by d304 on Jan 24, 2021 23:07:52 GMT
Hi Brian
Have a look at the AALS Copper Boiler code recommendations.
Based on bore diameter of 47.63 (sorry I work in metric!) and the outer diameter of the flange at 63.5, I would have a PCD of 55.54 with 10 4BA studs.
David
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Post by coniston on Jan 24, 2021 23:16:21 GMT
I thought that blower tubes were often used as a stay. If so, then the straighter the run the better. Not all Steve.. my boiler as of yet doesn't have the blower tube, I'll fit it later, it isn't a stay, just a plain tube.. in fact, my boiler doesn't have any longitudinal stays.. Pete That's Funny Pete, my DY drawing for the A3 boiler quite clearly shows 3 solid stays and the blower tube also being referred to as a stay. Top left of sheet 5. That is how my boiler has been made but as I am passing the blower steam through the outside ejector pipe I have fitted a screwed solid stay in place of the blower tube. Chris D |
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Post by Deleted on Jan 24, 2021 23:34:39 GMT
Not all Steve.. my boiler as of yet doesn't have the blower tube, I'll fit it later, it isn't a stay, just a plain tube.. in fact, my boiler doesn't have any longitudinal stays.. Pete That's Funny Pete, my DY drawing for the A3 boiler quite clearly shows 3 solid stays and the blower tube also being referred to as a stay. Top left of sheet 5. That is how my boiler has been made but as I am passing the blower steam through the outside ejector pipe I have fitted a screwed solid stay in place of the blower tube. Chris D Ah, but my boiler doesn't follow Don's drawing Chris...Paul isn't a fan on longitudinal stays on boilers over a certain length and thus follows some aspects of the AMBSC code. He's also not a fan of fixed blower tubes, following full size with swaged tubes which can be replaced if needed. Pete |
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Post by John Baguley on Jan 24, 2021 23:43:08 GMT
Brian,
Don mentions the number of dome fixings in the write up - it's 16 off 5BA on a 2.1875" diameter pitch circle.
It's going to be a devil of a job to fit that blower stay if it is bent. It has to be screwed into the blower valve first and then the blower valve screwed into the backhead. If the blower stay is bent first you've got no chance of getting it to line up with the hole in the front tubeplate plus I doubt if you will be able to rotate the stay/blower valve assembly to get it in as the bent stay will hit the tubes as you try and rotate it. I guess the idea is to thread the stay in whilst straight and hope it flexes as it goes over the end of the firebox and then poke about through the dome bush to bend the end to line up with the front tubeplate.
I'd try and move it further up if you can and keep it straight
John
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Post by runner42 on Jan 25, 2021 6:54:52 GMT
Brian,
Don mentions the number of dome fixings in the write up - it's 16 off 5BA on a 2.1875" diameter pitch circle.
It's going to be a devil of a job to fit that blower stay if it is bent. It has to be screwed into the blower valve first and then the blower valve screwed into the backhead. If the blower stay is bent first you've got no chance of getting it to line up with the hole in the front tubeplate plus I doubt if you will be able to rotate the stay/blower valve assembly to get it in as the bent stay will hit the tubes as you try and rotate it. I guess the idea is to thread the stay in whilst straight and hope it flexes as it goes over the end of the firebox and then poke about through the dome bush to bend the end to line up with the front tubeplate.
I'd try and move it further up if you can and keep it straight
John
Thanks John, I originally looked at the write up and couldn't find the details, However, I eventually found it on page 36. Let me have a bit of a moan about write ups in general, some aspects are covered by headings, but many are not and like many aspects of authors output, I don't understand the rationale behind what gets a heading on what doesn't. A good write up would include a heading for each part, so that in retrospect one can be directed towards the part in question without having to read through a multitude of dialogue to find what you are looking for. After all the write up is a reference and not a novel that has to be read from cover to cover. That's why I avoid write ups and expect that drawing details are annotated on the drawing and not hidden in some esoteric words and music. Brian |
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stevep
Elder Statesman
Posts: 1,073
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Post by stevep on Jan 25, 2021 9:34:50 GMT
Brian, Don mentions the number of dome fixings in the write up - it's 16 off 5BA on a 2.1875" diameter pitch circle. It's going to be a devil of a job to fit that blower stay if it is bent. It has to be screwed into the blower valve first and then the blower valve screwed into the backhead. If the blower stay is bent first you've got no chance of getting it to line up with the hole in the front tubeplate plus I doubt if you will be able to rotate the stay/blower valve assembly to get it in as the bent stay will hit the tubes as you try and rotate it. I guess the idea is to thread the stay in whilst straight and hope it flexes as it goes over the end of the firebox and then poke about through the dome bush to bend the end to line up with the front tubeplate.
I'd try and move it further up if you can and keep it straight John
On each of the boilers I have made, the blower stay is threaded, and is fitted to the boiler with a threaded bush of the same pitch. The fitting at either end (an elbow at the backhead end and a straight union in the smokebox) is screwed into the bush and onto the stay at the same time, so the stay doesn't rotate. |
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