The Diary of the Building of a 5" gauge Stirling Single

Feed pump

The eccentric for the axle pump was completed. When assembled onto the loco this will sit between the motion gear for the valves.

First the spigot on the end was set true in a 4 jaw chuck and then machined off for a reference.

Then the pump was held by the spigot set true in a four jaw chuck and a hole drill and then bored out the size to take 9/16" stainless steel pump arm.

Then the hole was further bored out to make a recess for packing.

The pump was set up late evening ready to continue the machining the next day.

The pump was set in the 4 jaw chuck so that it could be centered about inlet/outlet parts.

25th July 2010

Work on the axle pump continued.

First a cut was taken to bring the inlet/outlet to round.

Then it was turned end for end and put in a 3 jaw chuck and similarly machined, drill through for the port and then counter drilled to take the screw in fitting.

With that completed it was turned end for end again and the process repeated and here is the pump so far.

The inlet and outlet fitting were then made up from 1/2" hex brass and fitted with Stainless Steel balls.

On the inlet side a STAR shape was filed into the seating in the pump's body to allow water to flow in similarly a simple cross was filed into the outlet seating to allow water to be pumped out as is shown below.

A simple test with a mild steel plunger proved all was well with the basic pump.

26th July 2010

The pump inner Stainless Steel was machine from stock material.

28th July 2010

Today I was given a master class in using a slitting saw. I have never seen one operate before so I am obliged to my friend Martin who showed me how to use it and emphasised what a good asset it is to the workshop.

Basically it is a circular saw on a substantial arbor and run as the correct speed for the size of the cutter which is basically the same speed as using a standard tool in a lathe and cutting a bar of the diameter of the slitting saw blade.

In a matter of 20 minutes the stainless steel pump ram had its slot which drives the ram cut to perfection.

The cross member has been machined and the pump has been attached. Next comes connecting up to the Eccentric but there is quite a bit to do before that !!!