Machining a ball on the end of a rod---?

If you've used radius tools, or other form tools, especially on a small machine, you know how difficult it can be. Unless you're running quite large machinery, form tools chatter due to the large area of material in contact with the cutting tool. Rigidity is critical to good results, as is good lubrication. Often the form tool will cut pretty well, although leaving a rough finish. As you go for a good finish, allowing the tool to rub a little, up comes the chatter. The success enjoyed by the fellow machining 12L14 would likely be hard to get with almost any other steel. Lead is likely the secret to his success in this instance. On the other hand, you didn't mention the size of the radius, either. When they're small enough, it's not much of a problem.

Did you manage to take a pic of the engine? Love to see it.

Harold

Yes, I took a pic with the film camera, digital's in the shop. When I get them developed, I'll post one and let you know. The radius of these parts was small, as you suggested. The whole engine wasn't over a foot long. Watching a Corliss cycle running with the wrist plate and dash pots is a treat.

Pete Keillor

Well that explains why he doesn't worry about tempering. Such low carbon steel won't harden in the first place. (He could case harden the surface.)

Gary

I think you need to reread the post, Gary..

Tom

I have done quite a lot of "form tool" work on Stentor, RDS, etc., with excellent surface finish and tolerance. Does take a little experience to know how much feed, speed the job will tolerate.

Oh, he hardens the *tool bit*. Gotcha.

Gary

Thanks, Gary. Makes me a little more comfortable with myself when I see you miss something.

At this point, the score is:

Gary: 2 wrong.

Harold: Mostly wrong!

Harold