Continuing work part 2

I did quite a bit this weekend and didn’t think to get any pics of it. Just for the fun of seeing how it would turn out I stared the fermentation of 15lbs of red flame raisins in my main fermenter. It’s just the raisins, a couple pounds of sugar for starter, and the yeast. I’ll post more on it when I get the first taste and see if it was worth it. I also worked on the cast iron treadle base from the table project. I tried to braze one of the cracks but couldn’t get enough heat for the rod to stick and silver solder didn’t like the cast iron. I may have to get a specialty braze for it. The mead is still giving the occasional bubble in the water lock, so the ferment isn’t done yet. I am looking forward to pulling that batch and getting the first taste once it’s done, I’ll be posting that moment for everyone. And I spent Saturday morning partly on my Kenwood TS430S radio talking to people on 40m Ham bands and partly playing my bagpipes.

Yes, you read that right. Bagpipes.

 

I began the machining of a new valve guide for my 1929 Fairbanks-Morse hit-miss engine in part one HERE. It’s a couple weeks later and I felt like spending some more time on it, so here is the next bit in it’s making.

The inner bore where the valve itself rides is done, now I need to turn the outside down to be an interference fit with the reamed hole in the cylinder head. An interference fit means that the part to go in the hole will be just slightly larger than the hole itself so that the parts ‘wedge’ themselves together. They have to be a tight enough fit that when they get hot from running the engine, and expand at different rates, that they stay ‘wedged’. This also means that I have to turn the whole length of the guide to size, and I cant grab on to it with the chuck in the usual manner, instead I’ll have to hold the work piece from the inside while I machine the outside.

In the picture above you see the valve guide in the middle with and expanding lap on the left and a ‘live’ tailstock center on the right. The expanding lap goes into the guide bore and the center does the same from the other side. The pointy part of the center is mounted in bearings that allow it to rotate with the part it is contact with, thats why it’s called a ‘live’ center, it moves. All together in the lathe it looks like this.

Now that it is all in place it’s just a simple matter of turning the outside diameter down to size. Any machinists out there who look at the next picture, yes, I know that I’m cutting using the back side of the insert and it isn’t proper. I did it on purpose because there is just enough ‘spring’ in the insert holder that running the cut backwards gives a smoother finish. And since I need a fine finish for the press in fit, it works for me.

And the guide all finished inside and out, ready to be sized to length and pressed into the cylinder head.