Make a Windsor chair, and you’ll find yourself mounting a lot of 2″ stock on the lathe. Mount a lot of stock on the lathe, and you’ll probably find yourself wishing for a fast and accurate method of marking the centers.
I’ve used several different methods for marking centers, and never found one that I considered satisfactory. If you have squared-up stock, you can mark an “X” across the diagonals to approximate the center. It’s quick, but more often than not you’ll find that your stock is somewhat less-than-square, in which case, it’s inaccurate. If you’re using riven stock, it’s not an option at all.
Another method that I have used is taking a small compass and guesstimating the center, moving the central leg about until I find the proper center point. This is more accurate, and it works even for riven stock, but it’s also slow – and you end up with multiple center points (though I always try to mark the “correct” point more deeply) which can be confusing. A better solution is in order.
I came up with this simple tool:
To use, just center the tool on your stock with your fingertips, and give it a good whack with a hammer. You’re left with a perfect dimple, right in the center, that makes alignment of your blank on the lathe a snap.
I assume the tool is pretty intuitive, should you wish to make your own. Just pop a blank on the lathe and turn it to a cylinder of the appropriate diameter (2″, in my case). Make sure the bottom is perfectly flat or slightly concave, so it will be easy to center on your spindle blanks. Then drive a nail into the center (the tailstock conveniently makes a dead-center dimple) and clip it off about 1/8″ proud.
I made mine pretty with some fancy turned decorations and a coat of oil, but a simple cylinder would suffice. I figure a pretty tool will be less likely to get confused with a scrap and tossed into the kindling bucket when it’s inevitably dropped in the shavings.
This is the quickest and most accurate center-marking method I’ve ever used. It works just as well with riven stock as it does with sawn, and it will tolerate maybe 3/8″ of variation in the thickness without much loss in accuracy. They’re so quick and easy to make, it’s not a problem to make another center marker, for say, 1-1/2″ stock or any other thickness that you commonly use.
South Fork Timber 
I think this is a good idea, but in my experience, riven stock varies too much along the length to depend on what you see at the ends- you need to check the middle as well to maximize the turned diameter. Peter Galbert describes this in his book.
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You’re right, of course. I’ve not turned much riven stock for legs, because I don’t have the right species in my area, so I mostly resort to sawn stock. The times I’ve used riven stock, it was so straight that the ends and the middle were pretty much perfectly aligned. I realize that won’t always be the case, and some fudging to get the middle of the blanks center will definitely be required.
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Nice tip, I see myself making a few of these! Cheers
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