Stirling Single Wheeler in G3

Jon Nazareth

Western Thunderer
As mentioned earlier, I'm thinking of using Slaters GBG3 motor and gearbox to power the Stirling more than anything, because it's there. What do others use to power their electric G3 locos?

Jon
 

unklian

Western Thunderer
Slaters gearboxes are very nice. You might like to consider the GBG3-50C which with a 50:1 ratio might be more suitable for the larger drive wheels of your single, it also has I believe a more compact layout which might help too. The GBG3-50C has a Canon motor, there is also listed a GBG3-50U with an unspecified 24 volt motor . I am sure a phone call to David White at Slaters would get you any more information you might need .

Ian
 

Jon Nazareth

Western Thunderer
On the drawings that I have for the Single, it suggests 1/16" stuff for the guard irons but these would scale at nearly 1 1/2" which sounds very thick to me. Does anyone know of an average thickness for guard irons? I would have thought 1/32" which is something near to 3/4" would do.

Jon
 

jamiepage

Western Thunderer
Jon,
Some guard irons were substantial forgings, tapering in various planes, and even what look like flat plate irons were often thicker at the top to register on the mainframes.
But assuming the Sterling ones are bolt on flat jobs, I would vote to split the difference.
18 swg (1.2mm) would scale to 1 1/8in. which is an often recorded thickness for mainframes. It doesn't necessarily follow that the same material was used on the guard irons, but it looks about right.
You can see 18swg guard irons in a couple of photos on the project 0-4-4T. (Silver soldered and bolted in place).
Jamie
 
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Jon Nazareth

Western Thunderer
Jamie
Thank you for the answer. Having looked at other constructions, I can see that my tender's stretchers are far too engineered and will be quite heavy when finished, hey ho. Experience and all that :)

Jon
 

Jon Nazareth

Western Thunderer
Here are a couple of pictures showing work in progress on the tender. I've cut right down on the amount of metal that was specified front and back but it still needs a stretcher or two across the top. The pictures show the pieces of 1/4" thick brass that have been prepared ready for this job. My question is, does the team think that one will do or shall I use them both? On photographs one can see two bolts/rivet heads on the lower thin section of the large ovals, obviously they are there to secure something but, I've no idea what. To brace up the lower part of the frames, I'm thinking of using two narrow stretchers, one at the bottom of each oval of say, 1/4" x 3/8", this way that little detail will be taken care of.

Jon

IMG_1454.JPG IMG_1455.JPG
 

jamiepage

Western Thunderer
Jon,
A few thoughts, for what they're worth..
Two stretchers may be better for bolting on the tender superstructure? One or two bolts on each would help pull body flat to chassis.
Secondly, they've been cut now so why not use them both?
If you are concerned about weight, at least half the metal can be removed on each, I suspect, (lightening holes, reducing width or thickness between bolts etc) without affecting their structural value.

The rivets you see on photos probably relate to cross stretchers between sides, below the oval cutouts. Typically, (but not necessarily specific to the Stirling), simple thin plate stretchers with flanged ends would have sufficed. (See photo).
Assuming something similar was fitted, they would show on the model, so apart from adding rigidity would look good. Simple flat sheet stretchers with bent up ends could be soldered/ rivetted/ bolted as appropriate.
IMG_0008.JPG
 

jamiepage

Western Thunderer
Geoff,
It is a photographic copy of the Sharp Stewart original, provided a few years ago by the NRM.
And you're right, they are a joy.
Jamie
 

Jon Nazareth

Western Thunderer
Jamie
That all makes sense and bending some strip sounds a good idea. With regards to lightening, I may go for some holes as when I machined some of this brass, admittedly from one side only, it ended up a curve when I removed it from the vice. Maybe I should have removed some metal from both sides in order to even up the stress on this rolled brass.

Jon
 

Jon Nazareth

Western Thunderer
IMG_1452-002.JPG

I'm going to making up the brakes soon and will need some info on those brake 'rods', although I think they are flat bar and not rod. Measuring off this drawing, they look to be about 1 1/2" wide, can anyone confirm this, please? It's not that good measuring off these types of drawing as, in this case, the lines are about a 1/64" thick.

Jon
 

Stevesopwith

Western Thunderer
The GERS has a GA of the E10 Class 0-4-4 s 0f the late 1870s, on which the brake rods are noted as being flat bar, 1 1/2" deep, and 1" thick.
 

Jon Nazareth

Western Thunderer
Thanks, Steve, that's a great help. I'm trying to work out how to hang the brakes but I'm sure I'll get there eventually.

Jon
 

Jon Nazareth

Western Thunderer
Well, I've pulled this one out of the draw again with the thought of making up the brake hangers and rods. The problem that I'm facing here is that because it was designed as a passenger hauling loco, everything is rather over engineered. I started with the rear hanger only to find that the double thickness beam, same on outside as inside, fouls the inner 'stretcher'. I cut a section out which gave me a little more room, just. I then took a look at the second and third and these foul those huge stretchers. There's not much I can do about the first but I'm now thinking of replacing the middle two stretchers with 5/16" brass rod as I have some that size. It's not very clear in the above pictures but the stretchers and beams are held through the frames with 6BA countersunk screws. It suddenly dawned on me that these look terrible and that I can't have these on show as fixings for the tender. I don't know how others would build a G3 tender but these seem over the top to me. One thought is to countersink the holes in the frames and then to fill the slots, maybe with solder. we need a 'thinking' smiley.

So, what do people think of my stretcher idea, go for the rods which will give me more space to fit the brake hangers or is there an alternative?
Also, is this a good way of treating the countersunk screws?

All suggestions gratefully received.

Jon

PS. I shall use a much lighter approach when it comes to building the loco.
 

Jon Nazareth

Western Thunderer
IMG_1998.JPG

Well, I decided that if I was going to have, at least, a go at making up the brakes then, I would need to alter things. I've reduced the end fixings to just two per end and replaced the flat stretchers with square ones. All of the unwanted holes have been plugged with copper rivets and filed off flush. My countersink tool isn't very sharp and so, I'll need to buy another and slightly deepen the existing countersunk holes.

Jon
 
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