Boiler regulations now state that there must be two ways of getting water into the boiler under
pressure. Although I will have two injectors, I do like to have axle pumps. They are so easy
to operate without being bothered by water temperature and whether there is enough pressure to
give pick up.
My first mistake was not to think about fitting the pumps at an earlier stage before the wheels
were fitted, because now I have to make split eccentrics which are much more difficult to make.
I used a junior hacksaw to cut them in two being the thinnest saw blade I had, and of course,
they wandered off line.
This doesn't matter, as the two halves fit together anyway. Once
joined with cap-head bolts, I bored the inside to fit the axle. Then the outer turned again to
fit the sheaves dimensions. The second part of the picture shows the stages with chain drilling
to make the sheaves. The inside is bored on the 4-jaw chuck. I have made pump eccentrics in
the past using cast iron with steel sheaves, this time I found I didn't have any cast iron but I
had been given a large lump of brass bar which has been in the drawer for years. It will be interesting
to see what their life span will be. The next picture shows the completed eccentrics with the split
clearly seen. One sheave is threaded so that they can be adjusted to fit and then a locknut added.
The pump body is from a lump of unknown bronze, but, by the way it cut, it probably is a leaded
form. Perfect for a pump. The design is the usual with a stainless steel plunger fitted with an 'O'
ring and a second 'O' ring under the big nut. I was able to use my CAD to work out positions so that
they don't foul the brake system. This meant that they had to be fitted to a stretcher and at an angle
of 10 degrees. Naturally the stretcher is behind the brake cylinder so one of the stretcher bolts has
to be counter-sunk to avoid fouling the cylinder. I made the stretcher fairly substantial as I intend
to use it in conjunction with the rear buffer/coupler. I didn't have a suitable tap and die for the
thread on the pump body and the nut, so I cut them on the lathe.The final picture shows the pumps
assembled and fitted, although, as yet, I haven't made the ball valves.That's probably all for a
while until the festivities are over and then there is some decorating to do!
