OK Chaps her's the first instalment for machining the cylinders
The two inside Cylinders are machined from the same casting, as are the steam ports
A set of cylinder castings were ordered from Reeves this included the cylinder casting the end covers the steam chest and the steam chest cover
First job was to check the castings over and clean off any flashing, they seamed OK. Before starting to cut metal I always like to read up as much as I can about how other people have gone about the job, from this research I work out a method, in my head, that I think will suite me and the kit I’ve got. It also gives you chance to work out which are the critical features, as is so often found the critical feature is more to do with square-ness and alignment, the size of the bore are not really that important as you can make the pistons to fit if any thing the finish in the bores is more important than the size. If the bores are not square to the frame and parallel to each other the motion will bind causing wear and excessive loading.
I decided to follow the method in good old Curley’s words and music. He recommends using a faceplate with an angle plate mounted on it, squaring the casting up on this and bringing to size. The positions of the cylinders are marked out by first plugging the bore with wood, then by putting a parallel between the cylinder and face plate and pushing the cylinder hard up against the parallel, will ensure that bores come out square a good sturdy clamp over the top keeps it in place on the angle plate, you can know move the angle plate about on the face plate and everything will stay square. Using your centre height gauge get one bore positioned, and to maintain vertical alignment clamp a parallel under the angle plate, so that when you come to do the second bore you just need to slide the angle plate along to get the horizontal position.
You need to add balance weights to the face plate to counteract the out of balance mass from the angle plate and casting, you can use anything you have at hand for this, I cast up some lead weights from some old lead piping I had, but lathe change gears will do just as well.
Averything went to plan first bore machined up great, then with the second bore I decided to try coolant to see if I could improve the finish:- Desaster the coolant pipe got jambed between the job and the boring bar resulting in three dirty great grooves in the bore
Will Bandit come to save the day watch this space for next weeks thrilling instalment