Lathe tooling.

I made something similar to Oxtool's solution. I use the top of my cross slide as reference. Bottom of the reference post has a magnet glued in. There is a 40 tpi adjusting screw and a pivoted, off center disc that can be used over top of the tool. It is very stable, and my finger feel can usually get the tool right on center first try. The tool holder needs to be free to move up/down and adjusted to the reference post. Sometimes when the tool holder is locked down something moves a bit and so I always check after locking the holder down. The first facing pass will tell you if you got it right.
 
Here's Dudley Toolwright's video on lathe centre height, even references Joe P's video. Most importantly, he shows how his tool for measuring the height is made...


here's Tom Lipton's version:

 
All good methods of setting tool height. I just use a height gauge. The top of my cross slide is ground, so I set the height gauge base on it, chuck a miked ground pin in the chuck, and measure the height to the top of the pin. Subtract half the pin diameter, and stuck a label the DRO with that height to center that's there for good. Any time I add or change a tool, just measure to the top of the cutter tip with height gauge, and adjust the tool holder till it's dead nuts on. Once they're done, they're done.
 
Dabbler said:
I was going to describe how to determine centre on your lathe, and after thinking, I decided to refer you to Joe Pieczynski - he occasionally comes to this forum, and really knows his machining...

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Yep, I’ve watched a lot of his videos on YouTube
 
Hmm, that's in the same city as I am. Didn't know they had any machining related classes there. Last time I checked (err, has it been 10 years already?) they didn't. I'll have to check them out.

About 10 years ago I took welding classes in the evening in the vocational tech school near where I worked. Although I already knew how to weld, that was a really good class. Inexpensive tuition, free coupons and lots of hands on instructor time. Learned a heck of a lot. Well worth doing.
 
Dabbler said:
Here's Dudley Toolwright's video on lathe centre height, even references Joe P's video. Most importantly, he shows how his tool for measuring the height is made...
Click to expand...
I love Joe Pi's videos and techiques, but this seems like a lot of work to get a tool that adds a lot of stacked up errors.

I use a rule to get close, then take a shallow facing cut on anything round and soft. Then I adjust the height to remove any tit left at the center. Once found, I crank down on the lock nut so that it stays there. I've bought enough quick change tool holders so that the only thing that ever has to change is the insert.

To me, the beauty of carbide inserts is that they're all the same (in theory). I have some HSS for special situations, but generally it is just swap in an insert when necessary.
 
It took me about an hour to make my standard for my 12" lathe, and is accurate. It is 2 tenths low of centre, more than good enough.

I like your idea of refining your 'ruler reading' by taking a cut.

On a small lathe and with a 4 way tool post, I felt it was a large hill to climb to get everything on centre with carbide tool holders. I am sure he will get to carbide one day, but that is for later. On my 4 way tool posts, I have dedicated carbide tool holders that are milled and ground so they are always on centre when a fresh carbide insert is used. Makes tool changes very fast, almost as fast as an Aloris or Davidson.
 
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