I was determined to do better today so I went the long way round, starting with the basics. The first thing to do was improve the cutter. I gave it more rake and made sure it was a sharp as possible.
The next job was to set up the cutter to cut the correct diameter. Luckily the head on a 6BA bolt is an exact fit in the 3/16" guide die so used one to set the cutter.
I put a scrap piece of 3/16" in the chuck and cracked on. I didn't bother measuring the result of the cut. Here's the result, it threaded OK and a 6BA nut fits it nicely! The best test of all.
As a further check I polished the rod and tried it in the piston which is supposed to be a snug fit on the body of the rod. It's perfect.
Test OK so I cracked on with the rod.
All went well, I fitted the piston, it's a nice snug fit so I tightened it up because it doesn't need to come off again. Finishing touch was to chuck it and turn the excess thread off and reduce the nut slightly. There's plenty of clearance in the cylinder so the slight protrusion is no matter.
Here's a nice sight. The rod is a perfect fit in the cover and the gland and dead in line. Nice to see it coming together. Now for the valve rod and this could be a bit tricky......
I needed to reduce some 1/8" silver steel to 7/64". One way was to make a 1/8" die for the little steady, the other way was to file it down to size. I reckoned that I could get at least as good a finish with the file and diamond hone to I did it manually.....
I had to a bit of fitting on the valve chest and gland because the original design called for 3/32" rod but I have gone for 7/64" so I can thread it 6BA instead of the ridiculous 10BA in the drawing! A drill and a rat tail file took care of that and at knocking off time I had a cylinder with matching valve that only needs studding and fastening down. The valve rod is dead in line in the gland. Suddenly, we are on the verge of a working steam cylinder! Lovely and a nice satisfying morning's work.