By Jason Ballamy 
Part one
M4. C4n

This model is of the 5hp Galloway round rod, hit and miss engine to 1:3 scale so its quite a big old lump. Originally made by Richard Shelley the Galloway kits are now supplied by Liney Machine under the Minicastings range and are available in a number of different scales. You can also get them via Forest Classics in the UK.

Let’s start at the bottom. The kit is supplied with a sub-base and on the larger scale castings the four mounting lugs have to be added as it makes it easier to cast the base without them. These started off as a length of 5/8"square, hot rolled. These were cleaned up all round with a fly cutter, cut and milled to length and a hole drilled through each.

I then set up the vice on top of the rotary table with a stop and rounded the two ends.
The last job was to machine these to the correct height which got rid of the piece that was in the vice and, therefore, not rounded off.
I then spent some time shimming up the base with packers and feeler gauges to ensure that when the underside was machined it would sit true when turned upright.
The thin extremities of the casting had cooled quickly and ‘chilled’ the iron, luckily I was using a carbide tipped cutter as these hard chilled spots will take the edge straight off HSS tooling. It was then a simple job to clamp the casting the right way up to machine the top surface.
The sockets for the mounting lugs were roughed out with a drill and then finished with a 5/8" milling cutter.
Not a bad fit, these will now be bonded with JB Weld which will also be used to fillet the internal corners.
I also took a pass off the ends to remove some of the excess draught angle.
As I wanted to be able to bolt the bearing caps in place while doing some of the machining on the base, these were tackled next. The two edges were machined first, note the strips of aluminium to take up any unevenness between the vice jaws and the cast surface.
I could then support the casting on parallels while gripping by the previously machined edges to bring the base to thickness.
While in this position the step that locates the caps into the base was milled 1/16" deep either side.
The two ends were then machined square to the other faces.
The casting was then sawn in two and the cut ends machined but leaving the caps 1/8" over length.
The mounting holes were then spot faced and drilled. Make sure you follow the drawings of the base and not the caps for this as the holes are not central on one drawing but central on the other!