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Post by ejparrott on Aug 12, 2021 17:46:05 GMT
I am not a fan of the ball valves which are a 90 degree in themselves, not just the 90 degree of operation. We had one on a Romulus at our club which eventually deformed the sealing seats and leaked past, badly. The 180 degree type I've never had a problem with in use as regulators. They do take a little setting up to make sure the first 30 degrees of movement isn't just wasted travel, so the one on my Rom doesn't actually shut to the position the manufacturer intended, it's actually 'open' by about 10 degrees. I am tempted to try a rack and pinion drive on my Manning Wardle.
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Post by terrier060 on Aug 12, 2021 19:20:17 GMT
At the moment I have a replacement valve which I am modifying to fit, so that I can get the loco running again quickly. I do not like the present design as the only things holding the valve are the main steam delivery pipe, the valve spindle attached to the regulator handle and a support on the vertical inlet pipe, which prevents it from turning, but does not hold the valve firmly. This caused wear on the spindle entering the valve body, and the two O-rings were no longer touching the sides of the hole for the gland nut. I prefer to modify the Milner design of disc regulator which is firmly attached to the flange on the backhead (it forms the rear of the regulator body). Here is the disc regulator I have designed and built for the Terriers. Terrier regulator disc valve by ed cloutman, on Flickr
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Post by terrier060 on Aug 12, 2021 19:35:23 GMT
Yes Ed - I too am sceptical about the 90 degree valves. There are not many on the market unlike the straight-through.
I will see how the replacement one lasts, but make the disc valve type just in case. I think I shall have three ports rather than the two on the Terriers and maybe use a bronze stationary face and a PTFE rotating one.
Ed
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Post by terrier060 on Aug 13, 2021 12:16:23 GMT
Here is the new valve. Just needs pinning in the right position to give complete shut-off. I have sketched the better design using the conventional disc valve. I will have to silver-solder an extension on the gland boss so that the new regulator body can be fixed to it. The shape of the ports are as used by LBSC and are very simple and work effectively. The whole regulator is then rigidly fixed to the backhead and can be easily extracted for maintenance. Sorry about the poor sketch but I am not very good at drawing in PS. Proposed disc valve by ed cloutman, on Flickr
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Post by terrier060 on Aug 19, 2021 18:24:37 GMT
Very successful day today, though a little damp at the track but atmospheric! I managed to fit the new regulator in the boiler, though it was a very fiddly job. Instead of making the complicated gasket to accommodate the sixteen holes as I did last time, I thought I would try Loctite 574 flange sealant. I rang the engineer and he was very helpful and said that the medium strength sealant should do the job. I steamed up with some trepidation this morning, bravely ignoring the occasional shower, and watched the pressure rising in the boiler, expecting at any moment to see steam issuing from the turret! But nothing happened and the regulator was smooth in operation and none of the pipework leaked, as I had to remove the cab and pipework to the two injectors, the whistle, the pressure and vacuum gauges and the blower. I ran the loco for about an hour and a half before cleaning up and blowing the boiler down. The liquid gasket has saved me a lot of work. I do not know how easy it is to get off if I have to remove the turret again. I have drilled and tapped the lid of the turret to take three bolts which can be screwed down to break the seal should I need to remove it again. I will go ahead with the disc regulator design, just in case this valve has the same problems as the last. New regulator and flange sealant by ed cloutman, on Flickr
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Post by dhamblin on Aug 19, 2021 19:08:52 GMT
Well done Ed, light at the end of the tunnel! It's good stuff that Loctite 574 - also useful for sealing up blast cabinets Regards, Dan
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Post by John Baguley on Aug 19, 2021 20:39:36 GMT
I used 574 instead of gaskets when I assembled the cylinders for the 2½" Green Arrow and I can say that it's a devil of a job to get the joints apart again. After running on air and before painting I wanted to take the cylinder front covers off and remove the pistons so that I could wash the cylinders out to remove any bits of swarf that may have found their way in. I ended up having to tap a sharp knife between the joint faces to get them apart. The 574 seems to set solid and really bonds to the metal surfaces. I had to physically break the 574 to get the joints apart and it left a layer firmly stuck to both joint surfaces. I'm thinking of trying an alternative that doesn't set so hard.
It does seal well though
John
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Post by terrier060 on Aug 20, 2021 0:21:42 GMT
Thanks Dan and John for your useful comments. I did wonder about how difficult it was to remove, but was told that warming it up with a fine blowtorch does the trick followed by acetone. As I say above I have three tapped holes in which I can screw down some bolts to break the seal. This worked well when I had to remove the cover to see what the problem was.
Hopefully my last job is to put firmer springs on the axleboxes to make the loco more stable. The trouble with these Hunslets is that they have a large overhang, the firebox end being particularly heavy
I really want to get back to the Terriers which this thread is all about.
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Post by flyingfox on Aug 20, 2021 6:05:22 GMT
Greetings, I have used Locotite 572 for the same job for years, and there is no problem breaking the joint after many years if required. I use it on screwed threads also. I could best describe it as liquid PTFE. regards BB
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Post by John Baguley on Aug 20, 2021 8:26:20 GMT
Thanks Dan and John for your useful comments. I did wonder about how difficult it was to remove, but was told that warming it up with a fine blowtorch does the trick followed by acetone I'll try that next time. Thanks for the tip
John
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Post by terrier060 on Aug 20, 2021 8:57:06 GMT
Thanks Brian - it feels a bit like finding the Holy Grail after struggling to make the gasket and getting all those holes in the right place.
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Post by terrier060 on Aug 20, 2021 10:51:44 GMT
Maybe someone can help me with two questions. Question 1. I need eight new axlebox springs, because the present springs are too soft and the loco wobbles about too much, in fact it nearly throws itself off the rails in it's excitement! I am not sure what the present springs are made of, but they seem to have got softer over the last year or so's running. I have just checked and they are non-magnetic so probably stainless which may explain why they have gone soft? The dimensions are: Free length: 1.5 inches OD: 0.48 inches ID: 0.33 inches Wire diameter: 0.072 inches. Could anyone suggest a suitable rated spring dimension to stiffen up the loco without making it too hard, and most suitable material. There are two springs per axlebox which fit into location holes between the top of each axlebox and the top of the horns. This appears to deviate from the Milner drawings where I think he uses working leaf springs? Any advice would be greatly appreciated. Existing spring shown below. Question 2. The water in the saddle tank gets warm quite quickly causing the injectors to fail. I have to keep topping up the tanks with fresh water. This becomes a more serious problem if I leave the loco standing for 20 minutes or so while I have lunch. Not so much of a problem during normal running as I use more water, particularly on our track which has a challenging gradient which anyone who has visited will know. A great track to drive. I do not want to use the tender if I can help it, so the answer is to find some material about 1/8 inch thick which had a very high insolation value. I am sure one of you will know such a material and can point me in the right direction? spring by ed cloutman, on Flickr
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uuu
Elder Statesman
your message here...
Posts: 2,809
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Post by uuu on Aug 20, 2021 13:25:58 GMT
I've just fed your spring dimensions into this calculator: LinkIf yours are stainless, you get a bit more stiffness with ordinary steel. Using thicker wire makes things incredibly stiff. Reducing the number of turns for the same length gives a more modest increase, so might be the way to go. Wilf Edit - I've just put Jessie's spring dimensions into the calculator. These are 0.375" OD, 16swg (1.6mm), 1.5" length, 14 turns. They come out quite similar to yours, about 53 lbs/in . I did get a second set 0.4375" OD, 15swg (1.8mm), 1.5" length 12 turns, coming out at 61 lbs/in, as a standby in case I hit the same problem as you.
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Post by Roger on Aug 20, 2021 16:09:02 GMT
Maybe someone can help me with two questions. Question 1. I need eight new axlebox springs, because the present springs are too soft and the loco wobbles about too much, in fact it nearly throws itself off the rails in it's excitement! I am not sure what the present springs are made of, but they seem to have got softer over the last year or so's running. I have just checked and they are non-magnetic so probably stainless which may explain why they have gone soft? The dimensions are: Free length: 1.5 inches OD: 0.48 inches ID: 0.33 inches Wire diameter: 0.072 inches. Could anyone suggest a suitable rated spring dimension to stiffen up the loco without making it too hard, and most suitable material. There are two springs per axlebox which fit into location holes between the top of each axlebox and the top of the horns. This appears to deviate from the Milner drawings where I think he uses working leaf springs? Any advice would be greatly appreciated. Existing spring shown below. Question 2. The water in the saddle tank gets warm quite quickly causing the injectors to fail. I have to keep topping up the tanks with fresh water. This becomes a more serious problem if I leave the loco standing for 20 minutes or so while I have lunch. Not so much of a problem during normal running as I use more water, particularly on our track which has a challenging gradient which anyone who has visited will know. A great track to drive. I do not want to use the tender if I can help it, so the answer is to find some material about 1/8 inch thick which had a very high insolation value. I am sure one of you will know such a material and can point me in the right direction? spring by ed cloutman, on Flickr Hi Ed, Let me know the size you need, and I'll send you a piece of what I have, I've got a reel of it. It's a paper backed Graphited Polystyene which has a very high thermal value.
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Post by terrier060 on Aug 21, 2021 22:53:18 GMT
I've just fed your spring dimensions into this calculator: LinkIf yours are stainless, you get a bit more stiffness with ordinary steel. Using thicker wire makes things incredibly stiff. Reducing the number of turns for the same length gives a more modest increase, so might be the way to go. Wilf Edit - I've just put Jessie's spring dimensions into the calculator. These are 0.375" OD, 16swg (1.6mm), 1.5" length, 14 turns. They come out quite similar to yours, about 53 lbs/in . I did get a second set 0.4375" OD, 15swg (1.8mm), 1.5" length 12 turns, coming out at 61 lbs/in, as a standby in case I hit the same problem as you. Hi Wilf Could you type out the link please, because clicking on it gave an error. Many thanks for the details of your springs. I suspect that if I get steel springs to the same dimensions they will probably be OK. I suspect the stainless ones have suffered metal fatigue - does that sound likely? My guess is it does not hold its springiness like plain steel springs? Maybe I should do the same as you and get a set of heavier gauge ones as well. I have no idea of the weight on each wheel on the Hunslet. It would be good to get it weighed. Ed
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Post by terrier060 on Aug 21, 2021 22:56:39 GMT
Maybe someone can help me with two questions. Hi Ed,
Let me know the size you need, and I'll send you a piece of what I have, I've got a reel of it. It's a paper backed Graphited Polystyene which has a very high thermal value.
Many thanks Roger
I will measure the tank next time I am at the club. What is the thickness of the sheet?
Ed
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Post by Roger on Aug 21, 2021 22:59:35 GMT
I measured it yesterday, and I've forgotten already. It was 3.1mm or just over I think.
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Post by terrier060 on Aug 21, 2021 23:02:06 GMT
I measured it yesterday, and I've forgotten already. It was 3.1mm or just over I think. Thanks Roger - I will make sure that there is room under the tank. The boiler is lagged and has a thin casing over it as boilers are with no tank. There should be room but I need to check. Ed
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uuu
Elder Statesman
your message here...
Posts: 2,809
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Post by uuu on Aug 22, 2021 7:19:29 GMT
That link gives me an error too. I looked back in my browser history and it doesn't work from there either. I found it from an internet search for "spring calculator" - it was the clearest and most sensible one I found. He's another, which seems to work, but is not as nice: Spring calculatorWilf And another one: Spring calculator
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Post by terrier060 on Aug 22, 2021 12:20:40 GMT
Thanks Wilf, Roger Can anyone suggest the best material as I see from the calculator that spring steel is a much stronger spring than stainless.
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