Having completed all the running gear, it was time to see if I'd got it right and
run it on air. This meant constructing a unit to bolt to both cylinders with a 'T' piece to the compressor
. It started off but it had a very tight spot and then I remembered to block up the axles to their correct
working height. The tight spot soon disappeared and I ran it until the compressor was getting too hot.
On the final run down, the motion worked quite happily on 15psi. I'll probably have to adjust again when
the weight of the boiler is added. Which brings me to the next problem; the springing.I've no way of calculating the strength of the leading leaf spring; it's purely guesswork. Hopefully, it's on the strong side. Unlike the rear spring, I've used spring steel with multiple layers and untempered. I won't be able to do much about the adjustments until the engine has an all up weight.
One thing I have done which I think I should have thought more about, and that is the packing round the piston rod. I followed the drawings which use a countersunk distance piece between the gland nut and the packing. Sounds a good idea, but, the problem arises when you want to apply more packing or replace it and you find there is no way of getting the distance piece out after undoing the gland nut!
The springs weren't difficult to make; just a question of getting the rivet hole
in the centre of each leaf with some accuracy and getting the thickness of all leaves to fit the bracket.
I did put the leaves through the rolls to get the curve to match the drawing as hand bending is not satisfactory.
I've made the push rod to what I hope is about the correct length, but if it needs adjusting when the all
up weight is there, it won't be too difficult to fit a new rod. I did end up welding the bracket together
as it looked like the silver solder might not hold. To fit them in the correct place and get the length of
the rod correct, did mean that I had to fit the top lid to the tank which also meant the final coat of
paint to seal any possible holes. I used bitumastic paint, which I have used before. I also fitted a water
return elbow which will connect to the bypass tap.
Before I could complete the brake system, I had to fit the rear buffer. As it's a central single buffer,
the inside parts interfered with the brackets for the brake lever system. The drawing seems to have
omitted the position of the brake shaft which crosses the frame. I can't complete the brake system until
the floor has been fitted.
Before I do this, I'm waiting for the boiler to be sure of an accurate fit. I
would have liked to have fitted brakes to all six wheels, but unfortunately, there isn't room for the
centre wheels and the leading wheels would have had to have had the brake shoe on the leading edge in front
of the cylinder blocks. The main problem here was the well tank. I didn't want to drill in any more
holes and on top of that, the lever system to operate the brakes shoes opposite to one another, would
have needed to be under the tank and there is very little room. So the brakes are just as on the original
Romulus but, since they are only intended as a parking brake, they should be adequate. The main braking
being done via a vacuum brake to the train.
I decided to make the draincocks as I couldn't finish the brake system completely. I
can't finish these completely either. The connecting cross shaft passes close to the smokebox plinth, and
as I can't make this until I have the boiler in situ, I will have to wait.
The lever system is very
complex and a bit obtrusive so I'm considering using a wire inside a tube as the means of operating the
lever. This system works well although not exactly original. To hide any lever system under the chassis
would be difficult because of the well tank and this limits where brackets can be affixed.
The
draincocks are bronze with stainless taps and the springs are made of bronze wire which I happened to have.
Making the square holes in the levers is a fiddle as they must be done in pairs so that all cocks are open
at the same time and to the same degree. This meant making sure they were placed accurately and each one is
an individual. Identification marks are just visible on the underside of each and the corresponding mark is
on the inside of the lever. It's very easy to forget left and right pairs opening in opposite directions,
getting this wrong would mean that one pair of cocks would always be open whatever the lever position!
I
don't seem to have as much time in the workshop at this time of the year, as there are so many other things to do. Anyway, I'm going to be hanging around waiting for the boiler
which could be several months. That's about it for this month.