Connoisseur Models GWR HYDRA Diagram G19 Instruction Booklet - page 9
Solder the brake blocks, parts 13, to the brake hangers, parts 14. Then fold the bottom of the brake
hanger 90°. Holding the brake block with a crocodile clip, position it so that it is just clear of the
wheel tread and solder the bottom of the hanger to the floor. There are etched grooves on the inside
face of the side frames that the bottom of the brake hanger will fit into. These will help to position the
bottom of the hangers correctly.
Make up the screw coupling (there is also a pair of simple hooks on the main fret if
you prefer these). Solder together both halves of each coupling hook. Using round-
nosed pliers form the four links in to ‘U’ shapes, dress the tops of two links so that
they will pivot freely in the hole in the coupling hook. Pass one of these links
through the hole in the coupling hook and then spring the ends over the pegs of the
cast coupling centre, then fit the second link. Pass the coupling hook shank through
the slot in the buffer beam and retain it with a length of spring wire that will also
spring the buffers. Polish the centre of this wire with emery cloth first so that you
can solder it to the coupling hook shank once you are happy that the buffers spring
freely. I find that I get the best joint onto spring wire using fluxite paste
and 60/40 electrical solder.
8.
The buffers are a standard casting designed to be sprung and they work well on conventional
wagons. With the Hydra having deep, close together side frames, there is very little clearance and
the buffers are better fitted as solid. File a flat on to one side of the backs of the buffer bodies (to
form a D shape) so that they will fit centrally in the D shaped buffer beam holes. Then drill out
2.1mm the buffer bodies to take the cast head/shank. I hold the drill bit in a pin vice (chuck) and grip
the buffer body between finger and thumb. Use a little spot of spit on the end of the drill (some more
technical people have a block of furniture polisher’s beeswax that they smear on the drill end). This
will help to prevent the drill wandering in the white metal and breaking through the side of the buffer.
Drill through the body from each end so that the hole breaks through in the middle. Pass shank
through body and low melt solder together at the back. Tin the buffer beams with 145° solder and fit
the buffers using low melt solder. You will only be able to solder at the bottom so polish bright the
back of the buffer body and use plenty of flux to help the solder flow underneath.
This said it is possible to make the buffers
sprung. Prepare the bodies as before, then snip
off some of the narrow end of the shank to leave
just over 1mm from the step and after passing
the shank through the body, low melt solder a
retaining collar on to the shank. Make sure that
this is a good joint and that the solder flows all
around the collar. File a flat on to the collar (you
will need to file down to the shank at the brake
lever end) so that it will clear the side frame.
Offer the buffer in to place to check that it will depress without jamming on the side
frame. When you are happy with clearances solder the buffers into the buffer beam.
Retaining collar
Solder
Spring steel wire
Buffer Assembly & Springing
9. Fit the brake yokes, parts 15, by springing between the brake
blocks and spot soldering with 60/40 solder at each end. Pass a length
of 0.9mm brass rod through the holes in the brake lever brackets, Solder
into place and then cut each end so that they project 2mm from each bracket. Using long-nosed
pliers, fold up the brake levers, parts 16. Folding the ends around to form a handle with the circular
shield behind. Solder the levers to the projecting ends of the brass rod.
10. Fit the cast axle boxes/springs to the side frames, locating over the bearings. I soldered them
into place with low melt but they could also be glued on with araldite. Fit the cast vacuum pipe to the
buffer beam just to the left of the coupling hook. This casting is a very difficult shape to mould and
the master buried itself in the mould. To release it and subsequent castings I had to make heavy
knife cuts so that the mould would flex to release the casting. This tends to cause some casting
flash that will require cutting and filing away. That should now be the metalwork construction
completed.
Form up and
File Top Link
To Swing
Freely
Cast
Centre
Page 9