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Post by David on Aug 12, 2019 23:02:32 GMT
I'm glad to see you have used a banjo connection on to the blower tube. I cannot understand why so many designs have the valve screwed on to the blower stay, with live steam then fed to the wrong side of the valve - i.e. on the gland side. My loco has it done as you describe and that allowed it to become blocked by crud from within the boiler. Hopefully a problem no-one else will have! But if the crud had been on the other side it may only have stopped the blower valve closing completely..
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Post by simplyloco on Aug 13, 2019 11:33:37 GMT
After some VERY careful measurement of the 6BA tapped holes PCD I bit the bullet and drilled the required seven holes. I found the centre by my usual method of putting a MT2 centre in the quill and using the Mk. 1 eyeball method to get it right. Then, shock, horror, I actually used the DRO to move to the required radial position...!! 20190813_115049 by inkaboat, on Flickr I must have got the measurements right! I'm waiting on some 3mm stainless but I have this MS studding available to set up the regulator. 20190813_121911 by inkaboat, on Flickr I forgot to mention that the actuator was some 6mm short, so Mr H. Robinson assisted with the solution... 20190813_141158 by inkaboat, on Flickr Et Voila! I have the required travel, and I just have to drill 12 x 2mm holes in it and drill for the outlet and it's done! Oh, and of course silver solder the 6mm pipe, make some connections etc.etc.... 20190813_170523 by inkaboat, on Flickr
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Post by simplyloco on Aug 14, 2019 17:16:19 GMT
Just waiting on the stainless studs The eagle eyed among you will see that two of the radial holes are a bit close together so I increased the PCD a little. DSC00176 by inkaboat, on Flickr The 5/16" pipes require big unions, and I didn't have a die holder for this 1/2" x 32 die, so I turned things around. Worked a treat! I am scrounging some 5/8" hex brass for the pipe nuts from my very very very good friend David... s DSC00174 by inkaboat, on Flickr And I didn't have a big enough centre drill so I used my tiny boring bar on the same compound slide setting as for the big cones that I made earlier... DSC00175 by inkaboat, on Flickr
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,907
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Post by JonL on Aug 14, 2019 18:12:14 GMT
How eagle do you think my eyes are?! Coming together nicely. I wouldn't have thought of doing the cones that way but it makes perfect sense.
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Post by simplyloco on Aug 15, 2019 16:36:28 GMT
Still waiting on studs so I've made a start on the grate and ashpan. I want an easy drop and replace system, but the Scarth drawing looks like it never comes out! The Martin Evans design puts the pull out pin right in the centre of the grate, and the whole thing, with the loose grate, drops into your hot little hand... In addition, depending on where one wants to put the injector, the pin could interfere with its placement. I want to try this neat little rocker arrangement, putting a pivot pin at the rear of the ashpan, drilled through the inner firebox flange, out of sight between the frames. There will be a pull pin right at the front, going through a tube fixed to the ashpan, accessible through the wheel spokes. There is adequate clearance between the frames and no obstacles! Can anyone see any problems with this approach? Thanks John 20190815_171228 by inkaboat, on Flickr 20190815_170540[1] by inkaboat, on Flickr
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uuu
Elder Statesman
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Post by uuu on Aug 15, 2019 16:47:26 GMT
Jessie has a pivot grate, with about the front two-thirds swinging up, and the back third down, and the longer part rests on a support. The ashpan is fixed. A u-shaped cut out in the ashpan matches an inverted U in the firebox flange contriving to locate the pivot. The pivot has a square end, and a key through a hole in the frame swings it up so the fire, in theory, slides out of the open back end of the ash pan. Not having finished this yet, I don't know if it works!
Wilf
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Post by Cro on Aug 15, 2019 16:56:25 GMT
Grandads single the ash pan is fixed due to pipework running under loco for axlepump and now injector.
He hinged the grate at the front and put a pivoting catch under the footplate on back of boiler that you swing out the way and allows grate to drop at back. Back of ash pan is open as you have it. Will try photograph some bits Friday as I’m round workshop where loco is.
Adam
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Post by qreidford on Aug 16, 2019 0:57:29 GMT
Jon,
From my limited experience I would advise you to sort out your pipe runs before embarking on the ashpan! I began with a simple box and ended up with a plan form which had angles to accommodate various pipes etc. FYI I used the ga of reeves 1993 drawings which does work although getting it in place is faff.
Cheers Q
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Post by simplyloco on Aug 16, 2019 14:51:42 GMT
Thanks guys for the prompt and helpful responses re. ashpans, which has given me plenty to think about. I've completed the regulator, and it is ready to be nutted up and hopefully forgotten about! Incidentally, I tried to buy some 6BA stainless studding and it was hard to get and VERY expensive, even for MS. Try £6.75 +£1.50 for 300mm! M3 is just about the same pitch as 6BA, and I found ten pieces of M3 x 250mm ungraded stainless for £8.00, including two day delivery! I just used the 6BA die for 5mm one end, and opened up the regulator holes to accommodate the M3 studding. All is now sweetness and light... Studding here: www.ebay.co.uk/itm/29179261378020190816_134856[1] by inkaboat, on Flickr
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Post by ettingtonliam on Aug 16, 2019 16:05:58 GMT
Yes, stainless studding in BA prices is an eyewatering price isn't it. Its for this reason I'm considering using 3mm instead of 6BA for the fixings into Locomotion's boiler. I've got to make the nuts anyway, because they are square. Now, whats the availabilty of small sizes of square stainless bar ---?
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Post by Roger on Aug 16, 2019 18:30:52 GMT
Yes, stainless studding in BA prices is an eyewatering price isn't it. Its for this reason I'm considering using 3mm instead of 6BA for the fixings into Locomotion's boiler. I've got to make the nuts anyway, because they are square. Now, whats the availabilty of small sizes of square stainless bar ---? Here's some square 304 Stainless bar on eBay
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Post by ettingtonliam on Aug 16, 2019 19:54:59 GMT
Seems reasonable. Any issues with SS nuts on SS threaded bar galling?
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Post by simplyloco on Aug 16, 2019 22:21:41 GMT
Seems reasonable. Any issues with SS nuts on SS threaded bar galling? Do not over tighten and use copper grease. John
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timo
E-xcellent poster
Completing 3 1/2 Rainhill .Building 5" Railmotor and waiting to start 3 1/2" King
Posts: 234
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Post by timo on Aug 17, 2019 8:16:50 GMT
Yes, stainless studding in BA prices is an eyewatering price isn't it. Its for this reason I'm considering using 3mm instead of 6BA for the fixings into Locomotion's boiler. I've got to make the nuts anyway, because they are square. Now, whats the availabilty of small sizes of square stainless bar ---? When I was sorting out the cylinder studs for Rainhill I needed 7ba stainless which was unobtainable at the time so I had to make my own. The studs were difficult and the nuts made out of stainless hex were a just as bad. Was glad to see the back of that job! I tried all sorts of lubricant on the stainless but ended up cutting dry.
Tim
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Post by simplyloco on Aug 17, 2019 9:07:35 GMT
Finding out that M2.5 screws go into 7BA holes was a life changing experience... John
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timo
E-xcellent poster
Completing 3 1/2 Rainhill .Building 5" Railmotor and waiting to start 3 1/2" King
Posts: 234
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Post by timo on Aug 17, 2019 9:17:10 GMT
Finding out that M2.5 screws go into 7BA holes was a life changing experience... John John,
Thanks for that snippet - will file it away. Could save a lot of grief in the future!
Tim
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Post by springcrocus on Aug 17, 2019 11:11:19 GMT
Finding out that M2.5 screws go into 7BA holes was a life changing experience... John Damn, never gave it a thought. There are hundreds (or so it seems) of 5BA and 7BA fixings on the Allchin, and a PITA they are. Regards, Steve
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Post by Roger on Aug 17, 2019 12:08:41 GMT
Finding out that M2.5 screws go into 7BA holes was a life changing experience... John You can probably also take out 9BA from 1.9mm to 2mm to use M2 instead. The same goes for 5/16" from 7.938mm to M8 fine with either 0.5 or .75mm pitch. If you're making anything from scratch, there's a Metric thread for every occasion.
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Post by dickdastardly40 on Aug 17, 2019 14:37:11 GMT
Seems reasonable. Any issues with SS nuts on SS threaded bar galling? Brass nuts on stainless bolts/studding will give around the same strength without any potential galling issues and also without the need for lubricant. There is a misconception that stainless is stronger than carbon steel fastenings; an A2 rated stainless bolt is not as strong as an 8.8 rated carbon steel equivalent. It is just better suited to certain applications. Superb work so far John, it seems obvious that you will improve on the good bones of the loco from the condition in which you obtained it. Al
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Aug 17, 2019 16:38:06 GMT
At the risk of courting controversy, are stainless studs really necessary in the smokebox?
If the gaskets are working, there will be no steam from the regulator getting to them. The firebox is mainly full of flue gases and any char that is carried over, and the exhaust steam will be saturated in oil (or at least, containing oil), and should go straight up the chimney anyway.
The wet header of my Rob Roy is attached with 6 BA brass screws, as it was my first engine and I built it before I knew any better. Recently, I had to strip the smokebox, and despite not being undone for 40 years, they all unscrewed with no problem.
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