Enigma (Liverpool Lion)

Spitfire2865

Western Thunderer
Jon,
Thinking about that, it could possibly be done with 3D printed brass. 11/16 scales near enough to .8mm which is the typical minimum for unsupported structures.
Or you could scale up the thickness slightly and bring the minimum thickness to 1mm and print it with almost no issue.
 

Ian_T

Western Thunderer
I was thinking about how I might go about this earlier Jon. We were shopping at Tesco - and I usually get through my part of the list a good bit quicker then Herself and find it best to amuse myself somehow (rather than get too impatient!) :)

A traditional railway 'modeller' would (I think) try some form of lamination approach - possibly with two parts first pressed to shape and then joined along the centre line. This would be fiddly but is the sort of thing small scale folk do with etches.

You mentioned work holding problems and for machining small parts there are essentially two ways - either attach them to a sacrificial holder (with solder, super-glue or shellac) or keep them on the parent material for as long as possible. In this case, I think I'd try the latter and machine the general shape on the 'edge' of the parent piece. So for the long narrow section, lay the 'parent' flat (easy to clamp) - with the cutting forces going into the length of the parent body (e.g. milled from above) and which (when flipped over) will give an equal depth of cut for the opposite side. The slot could be formed with a fine saw and a filler piece inserted to close it. Once the general machining had been done, the part could be cut from the parent material and finished by hand.

There are other approaches and personal preference & experience will of course influence which is chosen. I'll look forward to seeing how you decide to do this but I'm sure the end result will be excellent.

Regards,

IanT
 

Jon Nazareth

Western Thunderer
Trevor
Not sure where you get the 11/16 from apart from the end radii. As mentioned before the inside measurements of the slot are .069" (1.8mm) x .024"(.6mm) and the thickness of the end of the arm nearest to the slot is .024" (.6mm) thick, all very tiny.

Ian
Thank you for the explanation but, and apologies for saying this but, I didn't quite understand :confused:.
I did think about joining two pieces along their length but after several attempts at trying to form half a slot, I gave up with that one. I did think of another way of laminating by making a sort of elongated sandwich without the filling, the lack of the filling would eventually be the slot but, I gave up on that because of the tiny pieces and holding them all together while it was soldered. Also, the line of soft solder would be visible when it was blackened. My latest thought is to make up the bar as a single piece of nickel 20/24 thou thick with the plunger as part of the bar, a little down stand. This would do away with the need for a slot and I'm hoping that when it is held in the clevis and sat in the top of the little brass piece which has a dimple formed into the top of it that that would be enough to hold it steady. Nickel because I don't intend to paint this item and if it is heated, when cooled, it takes on a good weathered steel colour.

Jon
 

Ian_T

Western Thunderer
I'm deep into my new 3D Printer (and the wonders of Cura) at the moment Jon - and I don't seem to be getting very far with either to be honest...

But if I get time, I will set my Taig up and machine some scrap brass to see if this will work for you in practice (I'm not sure - it's pretty small) - and then maybe a couple of photos will help make it clearer to you...a picture being worth a thousand words etc...

:cool:

Regards,

IanT
 

Jon Nazareth

Western Thunderer
Ian
Hang fire on the Taig, not heard of that before, until tomorrow. I've been working on the arms today and may have come up with a solution, not as per prototype but something that would suit. I ended up this evening trying to machine some nickel rod, not a success. I did try some a while ago and it just doesn't want to play nicely at all! Not rain but supper stopped play and I'll continue tomorrow and post, hopefully, some pictures of my work.

Jon
 

Jon Nazareth

Western Thunderer
IMG_3866.JPG IMG_3867.JPG IMG_3869.JPG

The firebox is virtually finished now and I quite like the way that the water gauge turned out. The first picture shows the gauge as acquired and it came from Geoff Nichols. Second picture with the cast glass removed and the faces cleaned up. The third with the gauge in place and a piece of perspex glued in as a new sight glass. There was a cast brass pipe in the lower fitting of the gauge which I cut off, drilled 0.5 mm and inserted the new copper 'pipe'.

Jon
 

mswjr

Western Thunderer
Jon, Some of the O gauge modellers do a similar water gauge to yours, And they drill a hole right through the Perspex ,And this then looks like the Glass tube inside it, Cracking modelling by the way .
 

Jon Nazareth

Western Thunderer
MSWJR
If I had known that, I would have given it a go. Too late now, though.

I put together this mock up to check to see if the smokebox doors would open once it was all together, and they do. My concern, though, was that the smokebox is very low to the ground. It is above rail height and I'll gain a little bit more once the coil springs have been fitted so, maybe, I shouldn't worry. The brass angle is there to show the top of the rail.

Jon

IMG_3872.JPG IMG_3873.JPG IMG_3875.JPG
 

P A D

Western Thunderer
Hi Jon,
What a fantastic build. You should take out the perspex and drill it as MSJWR suggests, as it really looks the part. This is the backhead for my Stanier 2 6 4 and I reckon in G3 the gauge glass will look even better. I could be wrong, but I think Nick Dunhill was the first to do this.
Cheers,
Peter
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Jon Nazareth

Western Thunderer
Peter
You were right, it does look good but, at the moment I'm reluctant to take it apart. However, I may go back to it at a later date and have a rethink.

Jon
 

Mike W

Western Thunderer
But I don't think LION should have the diagonal stripes which make it look even better - they were not invented when it was built.

Mike
 

Jon Nazareth

Western Thunderer
Well, the hinges defeated me. After two days of attempts at making them, I gave up. The alternative smoke box door can be seen in the pictures below together with the smoke box wrapper soldered in place. I'm crossing my fingers that the mat black paint will hide the undulations in the said wrapper. The bolts on the face are dummy bolts riveted over at the back. The prototype fire box is a mixture of bolts and rivets with gaps in between both. The middle axle is left out as I was fitting the motor. In the middle picture, you can just see the cutout in the firebox necessary to fit the motor.
The next item on the list is the chimney.

IMG_3906.JPG IMG_3907.JPG IMG_3908.JPG
 

Jon Nazareth

Western Thunderer
This is my first attempt at the chimney. Unfortunately, it leans forward slightly although it did look okay before I silver soldered the tube to the base, though. I'll have to make another but, luckily, I didn't solder the cowl on and so, I won't have to make one of those. Back to the drawing board or in this case, back to the shed.

Jon
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P A D

Western Thunderer
Hi Jon,
If it's just the tube leaning forward, could you not heat it with a torch and tweak it vertical with a piece of rod?
Cheers,
Peter
 

Mike W

Western Thunderer
I was thinking the same Peter. Its probably only one or two thou out at the base, but the length of the barrel makes it look worse. Mind you, I've done very little silver soldering but think it's not quite so easy to warm up and push.

Mike
 
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