Take a print of the sketches or make a rough sketch of the fixtures and clamps so
that you can refer to it as I mention them.
The next operation is to machine the soleplate to receive the Crankshaft Bearings
and is the one task that is not easy for the reader who is making the engine solely
using a lathe, unless there is a vertical slide available when the operation will
be quite easy using an end mill and filing the base of the space. As it is not essential
that the bearing is a close fit between the supports then filing the space (sides
and base) is probably the easiest approach to take. In fact, clearance is preferable
to provide adjustment so that the bearings can be aligned.
I will though detail the method I used which is part milling part filing. Mount a
small angle plate onto the top slide and the soleplate onto that, ensuring that it
is horizontal and the lower bearing mount nominally at the lathe's centre height.
Now, with small slitting saw mounted on an arbor in the three jaw machine the sides
of the gap to provided an opening of just over 7/16” and 5/32” deep, Photograph 9,
repeat for the second side. Remove and finish the radius by filling, as mentioned
I did subsequently find that when machining the similar component for the 10H that
the method above was not practical and had to find an alternative. I did then feel
that possibly the method adopted for the 10H would have been a better one for the
10V. The viewer may like to consider this alternative method that will appears on
a later page, in which case see photograph 80 and associated description. Drilling
the remaining holes is detailed later.
First, make clamp 3 , and using this secure the boxbed onto fixture 1 on the faceplate,
and machine its base. Then, remove, turn over, and fix it this time using two M3
screws through its fixing lugs and machine the top surface, Photograph 10.
Remove the boxbed from the faceplate and secure the soleplate to it using clamps
2 and 3 and drill the four fixing holes, 2.1mm in both parts using the cast in dimples
in the soleplate to position the holes, Photograph 11. Dismantle, tap the holes
7BA in the boxbed and open up the holes in the soleplate to 7BA clearance.
First, dress the top of the standard so that it will stand on this surface without
rocking unduly and clamp it using a single screw threaded into fixture 1 that is
already on the faceplate. Place a piece of thin hard card between the flange and
the fixture to compensate for any slight errors present. Set the flange to run reasonably
true, precision is not required, fully tighten the fixture's fixings and machine
the standard's feet, Photograph 12.