Harold Hall

Workshop Projects

The Box Bed 29

This is basically identical to the box bed on the 10V but longer and repeating the machining method would seem the obvious choice. However, in my case, the casting had a twist in it and if the top was clamped to the faceplate (or fixture) with an internal clamp as was done for the 10V it would pull the casting into the faceplate distorting it in the process.  Then, after the base had been machined and the Box Bed removed, it would return to its original shape and the surface just machined would no longer be flat. Most likely, others castings will be OK.


To avoid this, I clamped it to the faceplate using simple low profile clamps as seen in Photograph 74. The clamps have a single fixing and a grub screw either side of this to grip the workpiece. The taper on the casting is such that the Box Bed is bigger at its base and this was placed on the faceplate rather than the top of the casting. By doing this any possibility of the casting breaking free was virtually eliminated. Also, note the packing that is between the grub screws and the casting, always use a softer material, aluminium or copper, when securing castings as the softer material will conform to the rougher casting and improve the grip substantially. With the top surface machined the casting can then be turned over and clamped directly to the faceplate and the base machined, Photograph 75.


Soleplate 11

After doing the initial tidying up of the casting, stand the casting base down onto the surface plate and using a surface gauge check the heights of the four surfaces that support the crankshaft bearings, the aim is to get them the same  height. File those that are high and check again finally turning the casting over and checking the four surfaces against the surface plate checking to see if it rocks, the four should then be lapped as a group on a piece of course emery paper.


Now, mount it onto the faceplate using suitable packing and add a small angle plate to secure the other end. This arrangement will be better understood by reference to Photograph 76. If using a small lathe do rotate the machine by hand before starting it to ensure that the casting clears the lathe's bed. With that done start up and machine the casting's base. Having probably spent at least an hour deciding on the method, locating suitable parts and then mounting them on the faceplate, machining took no more than a couple of minutes, highlighting the fact that using the faceplate is frequently more about set up than the actual machining.

Stuart 10H steam engine machining

As I stated at the beginning, almost all parts that make up the 10H, Photograph  73, are identical to those in the 10V,  with just a few being basically the same but having different dimensions..


There is only one component  that is markedly different, that is the Soleplate(11). This replaces both the Soleplate (29) and the Standard (11) used on the 10V.  However, both the Soleplate and the Boxbed, being larger, stretched my Hobbymat to the limit, there being just 1/32” clearance to the bed when the BoxBed was mounted on the faceplate Unless the beginner has a very special reason for starting with the 10H my advice would be to make the 10V, not because of size but because the Soleplate is definitely more difficult to set up for machining if using just a lathe.

The Stuart 10H

Stuart 10H steam engine machining
Stuart 10H steam engine machining
Stuart 10H steam engine machining













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