miken
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Post by miken on Jun 11, 2016 18:21:47 GMT
I got some very nice springs in square section wire from the guy at the Midlands Model Engineering Exhibition whose stall Malcolm How interesting. I never thought to even inquire or look to see if they existed. I just assumed they wouldn't exist.
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Post by Roger on Jun 11, 2016 19:44:24 GMT
I believe Die springs are often available with square section wire. Most will be much too strong, but maybe there are small ones that are suitable for our purposes.
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miken
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Post by miken on Jun 16, 2016 15:47:34 GMT
A bit more plumbing. Apologies for the fact that I am using actual domestic plumbing elbows, but they are almost exactly the correct size. HP pipe is 8mm and LP is 12mm dia. picture shows the inlet for the lubricating pipe. The LP cylinder will of course be lubricated by the second hand exhaust steam and oil mixture from the HP cyl.
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miken
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Post by miken on Jun 16, 2016 19:34:48 GMT
I needed to come up with a joint along the length of the HP/LP steam pipes. It is severely restricted for space here as they have to pass between the double framing of the chassis. In the end I decided to make a push-in type of joint using ptfe. Webb used asbestos packing and a thin gland locking nut as shown in the drawing below in this position. If the joint isn't successful I could try substituting 0-rings or a combination of ptfe and o-rings. These joints also double as expansion joints on the prototype. Note F. Webb's signature at the bottom of the drawing Here is the pipework loosely assembled. The large inverted "U" tubes that go in the smoke box are steam receivers/reservoirs cum steam dryers. The little plunger on the l/h receiver is a by-pass valve to assist starting. If the loco is stopped with the lp engine on front or back dead centre it wont go, as of course the hp exhaust cant escape. So the driver can pull a rod in the cab which operates this valve and by-passes the big cylinder comlpetely and sends the hp exhaust up the chimney. The valve on the model is basically a large whistle valve. the plunger pushes a 3/8" dia viton ball of its seat and the steam escapes. Unfortunately this means that the engine has to pull try and pull away on the 2 small hp cylinders which drive the rear wheels only (there are no coupling rods to the other driving wheels). There are lots of pictures of Webb compounds in the station with the safety valves blowing off. The driver is trying to get the last pound of pressure so he can pull away!
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miken
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Post by miken on Jun 18, 2016 16:58:25 GMT
Boiler shell test completed at the club. So today I decided to trial fit and level the boiler in the frames using various spirit levels and a rudimentary height gauge made from a bit of plywood, a steel rule and a G clamp . This is the first time I have assembled the boiler,smoke box, front suspension, LP valve chest and smoke box pipework all at the same time. It all has to be assembled in the correct order or else you get stuck. The suspension hooks are dropped down this small sq hole in the smoke box wrapper and then the rivets pushed in. The LNWR used lots of round headed bolts with a key under the head. So you cant wind them in with a spanner or screwdriver. On the prototype there is room for a man to get behind to tighten the nut. I have no room so have to rely on pushing in a plain round headed rivet. Hopefully it should be OK as the spring tension will hold it all together. The problem will arise if I have to take it apart after a few years and the rivets are stuck. Then I will have to chisel the head off and punch it inwards.
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miken
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Post by miken on Jun 18, 2016 17:18:49 GMT
A thing I learnt today is that this loco is very front heavy. With the front radial axle box removed it still tipped forwards on the centre wheels and I haven't got the HP cylinders, front buffers, smoke box door or dome fitted yet! I was warned to expect this from a friend who is building an LNWR Jumbo. I'm going to need some lead at the back end.
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uuu
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Post by uuu on Jun 18, 2016 17:48:34 GMT
Wow! Not so much a smokebox, more like the innards of a church organ.
Wilf
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steam4ian
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Post by steam4ian on Jun 19, 2016 13:24:31 GMT
Mike
To get more weight on the rear wheels you could copy one of the builders at my club. He suspends the tender from the draw bar transferring tender down load to the rear loco frame. The front pairs of wheels on the tender have light springing, enough to keep the wheels on the rails while only the rear tender axle has heavy springing. In one case the tender is ride on. His two locos using this arrangement, which have both won awards at our national convention, are an SAR 700 Class heavy 2-8-2 and a Fletcher 2-4-0.
As for the plumbing, I hope you have remembered to solder all the joints.
Wonderful piece of work BTW.
Regards Ian
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miken
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Post by miken on Jun 19, 2016 19:48:13 GMT
Ian, I have heard of others using the tender to add weight to the rear of the loco. I may have to do something along those lines myself. In the meantime, I'm going to start attacking the outside cylinders and some other parts at the front end to see what weight I can shave off.
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miken
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Post by miken on Jun 24, 2016 20:22:15 GMT
I have shaved a bit more weight from the hp cylinders. Made the cylinder cladding(cleading?) and the front cylinder covers. Set the lengths of the extremely long piston rods and tinned the p/bz cross heads to make them look a bit like iron. Lagged the boiler Started making the boiler cleading (cladding?). The instructions written on the brass are for the bloke who is going to roll it for me. I would hate him to roll it the wrong way.
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Post by springcrocus on Jun 24, 2016 22:24:53 GMT
You really appear to have a head of steam at the moment, moving along faster than we can read. Cladding / cleading: I thought we'd agreed that if it insulates, it's cladding and if it decorates (as in external covering) it's cleading. Lovely job, Mike. And what I like most? Your workmanship is not hidden beneath a coat of paint. Steve
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miken
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Post by miken on Jul 13, 2016 19:37:39 GMT
I have been making the fire door. My 4 jaw chuck is a bit too clunky for small work so I borrowed a friends to make the latch and set it up like this: In the past Ive always made my fire doors from stainless steel. While this is very practical they dont really look authentic. So I have made this one from mild steel and oil blackened it. Although I have made the main door hinge part which protrudes into the firebox is in S/S. I notice from the picture that the black has already flaked off from the 2 short actuating levers. Is this because I have overcooked it?
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Post by Roger on Jul 13, 2016 20:59:27 GMT
The fire door looks superb. I don't know about oil blacking, I don't use it. You might try chemical blacking though, perhaps that's more resistant to heat?
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miken
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Post by miken on Jul 13, 2016 22:14:39 GMT
The fire door looks superb. I don't know about oil blacking, I don't use it. You might try chemical blacking though, perhaps that's more resistant to heat? My neighbour has restored old guns. I will speak to him
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Post by Roger on Jul 14, 2016 5:39:43 GMT
The fire door looks superb. I don't know about oil blacking, I don't use it. You might try chemical blacking though, perhaps that's more resistant to heat? My neighbour has restored old guns. I will speak to him The one i use is the Metalblak one which works pretty well. The only thing is that it doesn't really protect against rust. I guess you could wipe it with Silicone Oil to wet the surface and perhaps provide some degree of protection as well as a more glossy finish.
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miken
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Post by miken on Jul 14, 2016 10:34:07 GMT
My neighbour has restored old guns. I will speak to him The one i use is the Metalblak one which works pretty well. The only thing is that it doesn't really protect against rust. I guess you could wipe it with Silicone Oil to wet the surface and perhaps provide some degree of protection as well as a more glossy finish. Whenever I steam one of my engines I always put it back in its box dripping with wd40. So I think it should be ok.
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mbrown
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Post by mbrown on Jul 14, 2016 17:14:21 GMT
Some time ago, I acquired an almost full tub of Castrol molybdenum grease which had become slightly contaminated. I use it for "oil" blackening steel and it works a treat - having heated the steel to blue-ish, I dip it in the grease until the smoke has died down then withdraw it and burn off the remaining grease with a small flame. Unscientific, but it works for me... Only problem is that it doesn't take on any silver solder around the joints.
Malcolm
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miken
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Post by miken on Sept 20, 2016 21:42:19 GMT
Ive taken some time off from the compound recently to do other things. I now need to get stuck back into it. These locos were fitted with an unusual water bottom firebox. The water bottom part was notable for being virtually useless and added very little if anything to the heating of the water and must have added quite a bit to the cost of manufacture. Although it did lengthen the time required between washouts. Anyway, as mentioned earlier, my model is hopelessly front heavy so it occurred to me that i might be able to redress this by making an ash pan disguised as a (very visible) dummy water bottom firebox. Usually i make ash pans from 1.5mm sheet. I have made this one form 10mm plate with suitable solid wedges to help the draining of ash. I haven't weighed it but its a fair old lump. Hopefully the grate will slide through the front flap and up the rails into position. If you are wondering why the top line of rivets tapers off, its because the bottom of my bolier ended up a bit wonky and I had to mill the top of the ashpan to suit.
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jma1009
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Post by jma1009 on Sept 20, 2016 22:45:52 GMT
Hi Mike,
I am lost for superlatives to comment on your build.
We are talking about a very rarely commented upon type of LNWR loco unless you are a LNWR devotee, of which I'm not except it is something I have become increasingly interested in as the LNWR ran through the Sirhowy Valley opposite my home since 2002, deep into GWR territory in South Wales and the other Independant Valley companies pre 1923.
Fantastic work!
Cheers, Julian
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miken
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Post by miken on Sept 21, 2016 7:57:11 GMT
Hi Mike, We are talking about a very rarely commented upon type of LNWR loco unless you are a LNWR devotee, Thank you Julian, As it happens I am not a LNWR devotee. Im not even interested in full size railways. I just like making models of whatever takes my fancy.
I am fortunate in belonging to a club that has some very knowledgeable, helpful and supportive members and would recommend anyone starting this hobby to join their local club.
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