Elsewhere on the website I have discussed the considerations necessary when choosing
the sequence for machining a casting, and illustrated this by showing the methods
I adopted when making a Keats Angle Plate. With the same principle in mind. this
time I am making the Small Vee Angle Plate which, like the Keats, is also available
from “The College Engineering Supply”. Whilst performing much the same tasks as the
Keats it is constructed quite differently so provides a range of other possibilities
where machining is concerned. The castings for this are shown in Photograph 1.
The Vee Block
The casting is basically a six sided block with the two larger faces parallel and
the four shorter faces tapered and with the essential requirement for the finished
block being that the six sides must all be at 90° with their adjacent faces. This,
a major consideration when choosing the machining methods.
As was the case with the Keats, the first face to machine is one of the tapered faces
and whilst any one would suffice I chose one of the longer ones. Having carried out
the preliminary tasks of chamfering the edges and checking that the main face was
adequately flat for it to be mounted on the angle plate I machined the first face
as shown in Photograph 2. Then, with the casting still clamped to the angle plate
the angle plate was stood on its end, clamped to the machine table, and the first
smaller face also machined, Photograph 3. This ensured that the two faces were at
90° to each other without the complications presented by other methods. Whilst not
often a method to adopt do not loose sight of the fact that using an angle plate
in this way can occasionally be beneficial, providing that is, that your angle plate
is accurately made.
The next stage was to machine the opposite faces in a manor that would ensure they
were parallel and was done by mounting the casting directly on the machine table,
Photographs 4 and 5. The method in photograph 4 may look dubious but there is a second
clamp being used in the same way as that seen but hidden behind the casting. The
set up in photograph 5, and that also in the next photograph use my high profile
clamps. See here.