Some more important gubbins, the sanding gear. The kit has some rather nice cast sand boxes and...well..nothing else. Back to the Wild Swan book, measure and scale, and sketch up some parts that approximate to the real thing. Some of the detail is tiny and I'm not going to attempt it, even in 7mm. A decent representation will have to do.
If you're involved in mechanical engineering you'll know that 50% of all the things that get designed are brackets of some sort or another. The end of the sand pipes and the nozzles on the prototype are held in position by the mother of all brackets. It looks to me as if the originals are blacksmithed from 2" steel angle with another brackety plate bolted or riveted to the end, through which the sanding nozzle is connected to the valve (?) that combines the steam and the sand. There's no way around this other than making a lot of very small parts. Here they are...
Only showing 5 out of 6 sets because the first trial set is already fitted. The angle brackets are made from 1mm x 1mm milled brass angle, bent and filed to a slight taper on one leg.
The flat parts that look like the end of hockey sticks were marked on some scrap 0.5mm etch fret and cut out by piercing saw (see, I don't do it all by machine tool!). They're thicker than prototype but we need a bit of robustness in the model here.
The longer turned parts are the nozzles, and, yes there is a hole in the end. Not that it'll be noticeable on the model, but it keeps me amused.
The smaller turned parts are the body of the combining valve thingy. In reality it's a more complex shape than this because it brings the steam pipe into the sanding pipe at an acute angle, but I couldn't figure out how to make it easily. As you'll see in the assembled sanding gear a certain amount of cheating goes on.
The angle bracket is fixed inside the main chassis plate below the spring hanger. The small space for this on the prototype is mercifully also present on the model.
To assemble and solder together tiny parts like this you really need them to fit together mechanically. There's no chance of holding them in position accurately while the soldering iron is applied if they just touch end to end. So the spigot on the back of the nozzle fits through the hole in the hockey stick and into a hole in the combining valve. The 0.9mm wire sand pipe fits into a hole in the combining valve and a hole in the sand trap casting. and the sand trap casting is spigotted into a hole in the underside of the sand box. Makes a difficult job...slightly less difficult.
Once the angle bracket is soldered to the chassis and the hockey stick, nozzle and combining valve soldered together there follows a whole lot of bending and tweaking to get the nozzle exactly where it should be between wheels and track. There's no alternative to putting the wheels back in and sitting the chassis on track to check the nozzle position, then taking the wheels out to bend the bracket, then wheels back in and so on.
The nozzle has to be positioned so that it does not contact tyre or rail at practical suspension positions, and the bracket has to be sufficiently clear of the inside of the tyre not to contact at maximum side play. Eventually it all comes good. The steam pipe is 0.4mm copper wire simply soldered to the back of the combining valve, not quite prototypical but in practice you can't see that on the model.
Sand trap castings are not provided in the kit. That's bit of a surprise because other equally tiny cast parts are provided. Only the rear most sand boxes are outside the frames so it's only on those two sand boxes that you can see the sand traps. Bit of a head scratcher how to make these small and complex parts. I was ordering a few bits and bobs from Ragstone Models
Ragstone Models and just asked if he knew of any castings for these parts because they're not in his catalogue (or anybody else's so far as I can tell). Magically when my order arrived what should fall out of the jiffy bag but a little packet containing 4 sand trap castings, and I hadn't even ordered them! Which reminds me, I owe Mr Ragstone £2-00 for them, which seems a very small amount to pay to save a lot of work. Ragstone be praised!
You'll notice the missing brake blocks (won't you?). I've chosen to model up some for Mr Modelu to print. That way I can have them close to the tyres without an electrical short if they happen to touch. Some day they'll turn up along with the crew.
Here it is all gloomy and arty in the Gifford style. Can't wait to get to the painting and weathering down here in the crud and the murk.
I've just got five more to do now, and that'll keep me out of mischief for another week.
,and that's only for a six coupled loco!
