Recommended Calipers, Dividers, etc?

[Steve Mathews]

I've been putting off the purchase of some dividers, calipers and other small tools for woodturning until my needs could be better defined. So far a good divider or caliper would be handy. Any recommendation on what else might be needed? Manufacturer and source? I don't mind paying for quality tools.

[John Keeton]

It really depends on what you turn IMO. Most of my work involves close tolerances, and I use digital calipers - 12". I don't use the measurement aspect as much as I do the ability to lock the setting and to mark a "locked" diameter onto another piece of spinning wood with the sharp tips (actually only one tip!) If you are going to do a lot of spindles then having multiple sets of traditional OD calipers might be handy, though I have the Galbert calipers, as well, and enjoy using them when needed.

[William C Rogers]

For dividers and calipers I use Starrett. A quality tool. For digital calipers I use the $10 HF brand, good enough for the lathe. I just can't bring myself to us my Mitutoyo in that environment. I also have a $10 aldii brand that I like better as it holds the last setting wher I must rezero the HF. Haven't had any problem with either one.

[Steve Mathews]

John - The Galbert Caliper is an interesting device. Very cool!

William - You must be reading my mind. When John mentioned using digital calipers I cringed thinking of using my Mitutoyo on the wood lathe. One of the rare exceptions of owning anything from HF is my inexpensive 6" Cen-Tech calipers, which sits in a drawer by my table saw. Actually it was given to me but I find myself using it all the time on woodworking projects and general measuring. If a 12" caliper is recommended for the wood lathe I may follow in that direction. Coincidentally I was just looking at a set of Starrett Yankee dividers and calipers. What size do you recommend, especially for the dividers?

[Brice Rogers]

I use a smaller 6 or 8" caliper. I've got a couple of vernier that I will grab, or an electronic one (HF) or even a dial indicator. It doesn't really matter. It is usually just the one that is on top of my measuring instrument drawer.

But when I'm cutting a tenon or mortise, I use a 6" plastic ruler that I got at a trade show for free. If I'm doing that with green wood, I add or subtract to account for shrinkage during drying. I usually compensate by about 1/4". Sometimes that doesn't work and I have to recut the mortise/tenon. But even if it can still fit in the chuck, it often is no longer round so I re-cut in. If it is dry wood then I make the mortise or tenon about 1/16 to 1/8" bigger than my chuck jaws. So, a ruler works fine. No real need for three digits to the right of the decimal point.

I have a thickness gauge that I use and like. But I also use a David Ellsworth thickness gauge (heavy wire shaped like a "C". Works deeper than the fancy one does.

I also have a couple of flatness gauges that I use to visually see if the bottom of a bowl is flat. The flatness gauges are just short pieces of steel with a flat section. Works and is helpful.

[Kyle Iwamoto]

What are you measuring? If you're measuring a tenon/recess, I make a go-no go gauge with scrap wood. Free.
I agree with a wood lathe, 3 digit accuracy after the decimal point is pretty useless. I use a General from the big box store. I got it from Eagle Hardware before they got bought out. It's real old and still works.

[John K Jordan]

What are you measuring? If you're measuring a tenon/recess, I make a go-no go gauge with scrap wood. Free.
I agree with a wood lathe, 3 digit accuracy after the decimal point is pretty useless. I use a General from the big box store. I got it from Eagle Hardware before they got bought out. It's real old and still works.

I will echo Kyle's question: What are you measuring? Are you actually measuring something or are you sizing something on the lathe? I rarely need to measure precisely when woodturning.

The term "caliper" means different things. I have at least 30 things I call calipers in my shop. Some are very useful at the wood lathe, some not so much.

Some may be better called "dividers". Those with straight legs with points are perfect for transferring and marking a diameter on face work, say for cutting a tenon or recess for a chuck - set the distance with a ruler, hold the divider flat on the tool rest, and scratch the diameter with the left point only with the piece spinning (don't let the right point touch!).

Those with the legs curved inward on the ends are good for sizing groove on spindle or end grain work - cut a groove with a parting tool until the caliper/divider thing slips over the diameter. Some are spring-loaded and useful for checking wall thickness. Those with straight legs but with just the tips curved out are invaluable for sizing an inside diameter, such as a turned box lid, and for checking that the walls of an inside diameter are perfectly parallel where needed.

You can see some of these with straight and curved legs and pointed tips on the wall behind one lathe:
lathe_PM_cu2_IMG_5751.jpg

Another type of caliper is hard to be without when turning bowls, goblets, or the like. This is the type that looks like a big figure "8" with a pivot in the middle. Some are variations of the "8" with combinations of straight and curved legs. Close one end on the wall even deep inside a bowl or form and you can see the thickness by the gap on the other end. I have some quite large and one made of brass that is only a few inches long for very small work. (BTW, you can check wall thickness for free with an old trick with a piece of bent copper wire.)

Some "calipers" are vernier, dial, or digital tools for measuring. These can be cheap or expensive. I use precision digital Starrett and Mitutoyo mostly in my little machine shop. For wood turning I keep a couple of digital calipers to check drill bits and such. I have never found a need to measure a something on a wood turning to 0.001 inches. If I did, it would probably be different in a hour.

My most useful measuring calipers for around the wood lathe are dial, not digital, and with a fractional dial instead of decimal. This makes it easy to see if something is "about" 9/16" rather than have to think about what 0.5631 means. There are digital calipers that will also display fractions but I mostly find them annoying for fractions. BTW, the dial calipers never need batteries!
caliper_fractions.jpg
I never use these to size turnings.

These are my absolute favorite calipers while turning spindles. I primarily want to get a relative measurement instead of a precise measurement. As you might see on the upper one, I generally round the tips with a file and polish them so they easily slip over a sizing groove while the work is turning.
calipers.jpg
I keep maybe 10 of these in a small drawer by the lathe. When duplicating a spindle I'll preset several to the diameters I want. These are technically vernier measuring calipers but are not precise and are difficult to read to boot - no problem since I use them to match a diameter, not measure. I bought all of these on Amazon when they were about $4 with free shipping. You can also find them at Home Depot or a hardware store for not much more.

JKJ