Building the Stuart boiler feed pump part 2

The first impression on opening the small box containing the castings was it's very small. All the castings would easily fit into the palm of my hand. Stuart produce fine castings which are usually close to size and easy to machine, when I say easy to machine I am talking about the machinability not the actual difficulty or otherwise of the machining operation. Looking at the drawings made me question whether attempting this model was a good idea. The most daunting looking components were the cylinder and steam chest. I spent a long time looking at the drawing trying to make sense of it, there is an awful lot going on in a very small space. In the end I decided to make a start on the frame.

The bore for the steam cylinder and water pump must be perfectly inline and square to the mounting faces.

I cleaned up the casting with a file and then mounted it in the 4 jaw chuck. Note the u shaped packing to clear the lug on the top surface.

I took a lot of care setting up and then drilled and bored both holes at the same time.

The next step was to machine the pump mounting face without altering the setup. We now have two bores in line and to size with one mounting face at 90 deg to the bore.

The next task was to turn the casing round making sure that it was hard against the chuck and running true, I used an indicator on the bore.

As a bit of displacement activity I decided to machine the cylinder covers next as I still had not worked out how to tackle the cylinder and steam chest. The covers are simple turning jobs and can be done in the three jaw chuck.

The finishing of the outer surfaces was left until they could be tried against the cylinder and valve chest.