Stuart Oscilator, Episode 1

[nikko]

Hi there, Heres the first installment of my Stuart oscillator build. I
decided to attack the cylinder first. The starting point was the
cylinder casting, which was in fact a brass extrusion with 3 grooves
for the studs equally spaced around its perimeter. In the absence of a
4 jaw chuck, it was offered up to the 3 jaw to see what happened and I
found that the grooves lined up with the chuck jaws perfectly and when
tightened everything ran nicely on centre. The job was then faced both
ends and brought to finished length. Before removing from the chuck,
the centre was spotted on with a small centre drill. The port face was
next, this was also done in the 3 jaw, but mounted on its side and
squared off of the topslide (see photo).The distance fron centre to
portface was marked and was faced to size. The next job was to machine
the bore. The embryo cylinder was drilled through and bored to size
with a homemade boring tool ground up from a length of 3/16 tool
steel. A rudimentary cylinder hone was made up from a piece of dowel
sawn down the middle for about 3 inches, strips of 800 grade wet and
dry were placed in the prepared slot and liberally charged with oil
the cylinder was slid on and the whole lot mounted in the chuck with
tailstock support. The machine was then run at a slow speed whilst
holding the cylinder and sliding it up and down the hone, in no time
at all a nice finish was achieved inside the bore.Everything was
checked with my trusty digital vernier and found to be done to a
nicety, both ends at 90 degrees to the portface and the portface
paralell to the bore(most important!). All that is left to do now is
drilling the steam passages and the tapped hole in the centre of the
portface for the cylinder pivot stud.Well, thats it for now, more as
job progresses. I have posted some pictures in the files section,
apologies in advance for my dodgy photographic skills.
Regards
Nick