SSM GNR(I) "S"-class 4-4-0

[Horsetan]

I would say its a rocking shaft driven by the ecentric arm or extension of the ecentric arm. The valve will be pulled or pushed the opposite direction to the ecentric movement. Driven from below.

 

In that case, it may be as well to also adapt parts from the Brassmasters 4F inside motion kit - the crossheads do look suitable.

[Lough Erne]

The piston valves are operated as mike says through a rocking shaft.

From the eccentrics on the driving axle the expansion link is moved back and forth which in turn is suspended from the weight shaft. From the expansion link there is a connecting link which is supported on both sides of the frame spacer and this rocks back and forth. At the cylinder block side of the spacer as seen in the photo the connecting link is connected to the steel casting that the valve spindle link is connected to. This means as mike says that the valve is pushed/ pulled in the opposite direction of the throw of the eccentrics.

I will take a few photos at the weekend and put them up

[Lough Erne]

meant to add

 

It is roughly similar to this apart from the fact that the piston valves are above the main cylinders and as seen in the photo has an additional rocker assembly to lift the valve travel above the cylinders

 

http://www.steamindex.com/locodesn/cylinders.htm

[Horsetan]

....I will take a few photos at the weekend and put them up

 

Wonderful. Thanks

[Horsetan]

Right so, I'm just after completing the shell of the smokebox. Photos to follow as Windows Phone 8 will not work directly with the Forum upload software.

 

The smokebox shell is easy, but mounting it on the footplate reveals some flaws in etch design which "Weshty" might want to have a look at if he gets time to revisit the original artwork that he inherited. These flaws also affect the mounting of the front frame plates, making the job a little harder than it should be.

 

The real killer is forming the smokebox wrapper - you have to go slowly and carefully on this, and it helps to have the use of a rolling mill. The reverse curve where the smokebox sides become vertical must be marked out because if you get it in the wrong place, it will be the very devil to correct. I'll show yis how I did mine.....

[David Holman]

Wonderful stuff - always look forward to seeing the latest postings. Have done outside Walschaerts and dummy inside Stephensons, but inside motion really does move it up a level, even in broad gauge.

[Lough Erne]

I have put a few more photos up showing the area requested. Hope they are ok as the camera died before I could take anymore. In other news, 131's frames were lifted off her wheels today - the first time since her rebuild in Dundalk in the late 50s.

[Horsetan]

I have put a few more photos up showing the area requested. Hope they are ok .....

 

Brilliant!!!!

[Horsetan]

Now, some photos of what was done over the weekend....

 

 

The smokebox is the subject of our attention, and the kit provides a basic fold-up shell (Part P13) which we saw out of the fret:

 

 

Stick it in the vice:

 

 

....and start folding:

 

 

 

As can be seen, there are tabs underneath the smokebox sides which are intended to fit into slots in the footplate.

 

The front and rear of the smokebox shell have tiny etch marks; these act as seats for the tops of the smokebox sides:

 

 

...and this is how they fit:

 

 

A minimum of solder is now run into the inside corners, and eventually, we get this:

 

 

...which means we can test-fit it onto the footplate:

 

Edited December 24, 2013 by Horsetan
Part number added

[Horsetan]

It's not all plain sailing, as we will now discover. First, I took out the post-1938 front frames (Part P16 and P17) from the etch:

 

 

 

These have two layers, with the riveted layer being attached last of all.

 

The inner layer has no tabs at all along the base, so trying to hold it in place is going to be the very devil:

 

 

 

Note that the left-hand frame has a tiny notch in the top - this is where the lubricator and its bracket will be places.

 

Now, let's have a look at the underside, so yis can see what I mean: if the slots in the footplate are going to be that long, why not have tabs on the base of the front frames to fit into these, and provide a stable location?

 

 

"Weshty": what d'ye think? Is it worth modifying the etch artwork?

Edited December 24, 2013 by Horsetan

[Weshty]

Horsetan,

 

These etches were done 30 years ago and the handdrawn artwork has long since disappeared and is certainly not available to me. I would have to recreate the etch design from scatch using the etch transparancies as a template.

 

Straight up this is not something I can give priority to, given I will have my hands full with the ammonia rake.

[Glenderg]

Send me up an etch Des, i'll redraw it for ya

[Horsetan]

.....These etches were done 30 years ago and the handdrawn artwork has long since disappeared and is certainly not available to me. I would have to recreate the etch design from scatch using the etch transparancies as a template.....

 

Ah, that's a shame. Lost in the mists of time. Never mind, it was just a question that occurred to me as I went along.

 

Send me up an etch Des, i'll redraw it for ya

 

You'll have to build it, though....

Edited December 27, 2013 by Horsetan
Additional comment

[Horsetan]

Smokebox front overlay soldered on tonight - the bottom of it has an upward curve, which had to be formed using the handle of a needle file to get close to the right curvature.

 

Front frame laminates also assembled but will not be added to the footplate until the smokebox wrapper is on......

 

I think I have made a mistake with the buffer beam. Can anybody spot what it is.....?

Edited December 24, 2013 by Horsetan

[Horsetan]

The next bit of the work was - on the face of it - simple: seating four tiny caps into the half-etched marks shown for them on the footplate. The etch provides five, just in case you lose one of them:

 

 

I tinned the backs of four of them with the usual 188 solder and Carr's Green Label flux:

 

 

However, separating each individual cap, filing off any excess tags, and positioning them is the very work of the Devil himself:

 

 

Eventually you get there:

 

 

...though if you use too much solder, you end up having to scrape all the excess off (as here).......which may take you longer than it did to position the caps in the first place.

 

With all four caps soldered in their correct positions, I could then add the front mounting 10BA nut. This is simply screwed tight in position using the matching 10BA bolt, brushed all around with flux, and soldered. The reason why it's screwed tight is to prevent solder leaking in towards the bolt and soldering that solid!

 

 

I test-fitted the smokebox shell, just to see where we were:

 

 

...and you can also see the curvature at the base of the smokebox front overlay. This is why you solder the front overlay at the top and upper sides, BUT NOT THE BOTTOM! As stated earlier, I used the handle of a needle file to form the curve, but you could also use a 3mm dia. drill bit. A useful point to note when forming the curve is to ensure that, when finished, the base of the overlay should sit perfectly on the footplate. If you can see a gap, your curve is too tight. Conversely, if the smokebox shell won't sit neatly on the footplate, it means your curve is too shallow.

 

This can be a difficult area to get right, and photographs of 171 and her sisters don't always show the curvature clearly.

 

I moved on to solder the preformed firebox and boiler barrel together:

 

 

....and since all the soldering is on the inside, with luck you should end up with a flush joint on the outside:

 

Edited December 27, 2013 by Horsetan
extra photos

[Horsetan]

I know this is getting slightly ahead of ourselves, but I couldn't resist just fitting the sub-assemblies together just to have a look.....

 

 

I think it's starting to look more like the "S".....

[Dunluce Castle]

Superb work, can't wait to see her finished and painted, GNRI blue I take it?

[Horsetan]

...., GNRI blue I take it?

 

171 was only ever going to be blue.....

[Kirley]

I take it there is photographs with these posts but I'm not seeing them?

[Glenderg]

I take it there is photographs with these posts but I'm not seeing them?

 

Same here K.

[Dunluce Castle]

I can see them perfectly and I'm using chrome on iPad.

[Horsetan]

I take it there is photographs with these posts but I'm not seeing them?

 

Same here K.

 

That's weird. I uploaded them and they all show up grand here....

[BosKonay]

Looks ok to me ?

[scahalane]

Nothing showing up for as well!

[BosKonay]

Can someone who cant see them see any image placeholders or anything at all?

[BosKonay]

[Horsetan]

I have no idea what's going on with the images. They are uploaded into the normal albums, all of which are publicly viewable. I posted them up using the standard forum image links and they are visible to me in IE, Firefox and Google Chrome.

 

Not being any sort of IT expert (feck, I only use the thing), is there some sort of coding error that makes the images visible to only a few people?

[Glenderg]

It's an android problem from what I can make out. On the wife's older android no placeholders or little x's present to indicate a photo. Just fixing her sisters tablet now and it's all good. I think she's on jellybean.

 

Very impressive horse, glad I got to see the photos! Richie.

[Horsetan]

....I think she's on jellybean. .....

 

She's on what? I've never heard it called that before

[Kirley]

I take it there is photographs with these posts but I'm not seeing them?

 

Now I go back to this thread the pictures are there... puzzled!

[Horsetan]

Now I go back to this thread the pictures are there... puzzled!

 

Delayed reaction? Who knows? Enjoy the photos, anyway.

 

More to come.

[Mayner]

Looking good, I look forward to the chassis build.

[Lough Erne]

I have put another 2 photos in the album showing the slide valve crosshead which I hope will be of use or interest. It is unfortunately rather difficult to get a decent photo of the slide valve crosshead due to the proximity of other bits of valve gear and the trailing bogie axle.

[Horsetan]

I have put another 2 photos in the album showing the slide valve crosshead which I hope will be of use or interest. It is unfortunately rather difficult to get a decent photo of the slide valve crosshead due to the proximity of other bits of valve gear and the trailing bogie axle.

 

It all helps. Thanks.

 

As it happens, I have another 4-4-0 kit with inside motion - the ex-Great Central/LNE D11. This is an old Perseverance kit, and the inside motion frets for it were designed by Peter K Dawson. Some of the smaller links appear broadly similar to the "S", so some duplication might be possible.....

Edited December 29, 2013 by Horsetan
Update

[Weshty]

Horsetan, great photos, now that I can see them, I'd the same issue as the other lads a few days ago. Looking very well altogether and very self explanatory. Well done sir.