One way to find center.

Like Bob for most general turning work it's fast and simple to just use the 6" scale. If you need to be dead on center for facing take a piece of scrap and do a facing cut. If there's a nipple left adjust the tool up or down to get on perfect center. Once you hit perfect center the face should be smooth from one side to the other. If you're using quick change tooling lock the adjusting nut in place. The tool should remain on center. About the only way it would be off center is if you had run out in the chuck, a poor quality tool post or holder, or stock that isn't truly round.

In all my years in a machine shop I've never used a depth mic to find center, and I've never seen anyone else do it either.
 
Good idea. I just eye ball it. Been doing that way for decades without problems. If I’m facing and need it perfect with no nipple, then I take the time to adjust as necessary…Dave
 
I’ve been a machinist for over 60 years and most times I just eyeball the tools for getting to center. And have been using the 6” scale since I started cutting metal.
But when I am cutting tapers I try to get as close as I can to center and find the depth mic works great. The depth mic in the video has been used for close to 50 years and so far there is no damage to the mic spindle. And all my years in a machine shop I have never seen anyone else use a depth mic to find center.
So what , It works great for me. And that is why I named this thread ( one way to find center.)
 
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Dinosaur Engineer said:
This is one way of damaging the end of the Mike spindle.
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I think that Jimsehr likely uses common sense and due diligence but not driving the top of the tool into the spindle but carefully adjusts the tool holder adjusting nut up to the micrometer spindle. I used his approach just this morning and see no issue providing one doesn't drive the tool into the spindle.
 
Jimsehr said:
But when I am cutting tapers I try to get as close as I can to center and find the depth mic works great.
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Jim, I understand the importance of being on exact center when turning accurate tapers. When finding the center of a taper with the depth mic, how do you position the depth mike over the work at the correct axial length? The depth mic has axial length as well, actually different ones at base and spindle. Your only photo appears to show a cylindrical work piece. Please clarify...
 
Bob
When I’m setting my tool centerline I try to keep center of depth straight on top of round dia and mic down till I get a reading. It’s hard to get a different reading unless
you are way off center. Try it and you will see how it works. As someone said they never saw it done in all their years in a shop. Well I never saw anyone else do it either. But I started doing it about 50 years ago. Just keep the base of mic parallel to the round dia .
 
The photo of you doing it on round stock makes perfect sense to me, great idea. When a taper is introduced, I do not see how accuracy is achieved. ???
 
Bob
I always set tool center on round dia before I start cutting tapers. I also have made a tool for my Logan that I call a ( taper slide tool ) that cuts like a compound that is
Somewhat set like a sine plate on it’s side . After I have set it for a taper I drill and ream a locating hole thru top and bottom plate so that if I want to later on repeat that taper I just put a pin in it and it’s ready to go. So if I want to cut my Logan spindle taper I pin that hole. If I want to cut a Morse 1 taper I pin that hole etc.
 
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