Calipers accurate?

[Jonathan55]

I haven't posted for a while but have learned a ton over the years reading this forum.

Opinions please.

I bought an expensive set of calipers ($37.75 is expensive to me,) from a well known national woodturning supply. "Versa Calipers." When I got the first set I noticed that when the two arms that would go against the walls of a bowl touch, the other two arms that show the thickness are still almost 1/8 of an inch apart.


This seems less than accurate to me. I have a "cheap" $12 pair of calipers that, while they seem flimsy, at least both ends meet at the same time. If I'm trying to make a bowl 1/4" thick and the calipers are nearly 1/8" off then I think I'm just estimating. I emailed them about this and though I didn't get a reply I eventually got an email that they had shipped a new set of calipers and a return label.


The new set is not perfect but these have about a 1/16 inch and the off by about that much side to side.


If the $12 calipers weren't perfect I'd accept that but for the money I expected more I guess.


Am I just being picky?
Jonathan

[Arlin Eastman]

I really do not like using the double ended calipers

I always use this one

[url=https://www.woodturnerscatalog.com/p/86/5929/Groz-8"-Outside-Caliper]https://www.woodturnerscatalog.com/p/86/5929/Groz-8"-Outside-Caliper[/url]

which is an 8" and I hope to get a 12" to 16" for bigger. If you set it at whatever thickness you wish then you can follow it down into the inside.

Arlin

[SteveS]

I have the cheap ones from craft supply. I just bent it enough to make both sides match.

[badwhiskey]

I don't think double ended calipers are designed for planning a moonshot, but 1/8" off is too much.

Which way are they off? Do they show the bowl walls too thick or too thin? Can you grind a little off the offending part to make them close to perfect?

I can look later to see how close mine are, but I know it is better than 1/8th.

[theeviltwinn]

I expect everything I buy to be "right" right out of the box. You can bend the arm and make them work but you shouldn't have to. Send them back for a refund and buy a different brand.

Twinn

[chips ahoy]

Buy a set from Lee Valley, I have never had an issue with mine.

Mel

[Bill Holt]

Send'em back! If we accept the defects, they will just continue selling inferior products.

It is a pain in the backside, but we all have to demand better!

[NCPaladin]

JMHO but first, I assume they are made from stamped out steel so they should be correct.
Next I just don't like the figure 8 calipers.

I posted a pic/link to the type you may be taking about.
As the pic illustrates the calipers must be constantly swung around in order to maintain a direct thickness of the bowl. In the pic the rim may be 3/8; because the caliper is not swung around it measures more and more at an angle through the wood. So you may start with the caliper parallel with the bed and by the time you reach the bottom it may need to be almost perpendicular to the bed.
You are watching for change between the two points on the outside which to me is very difficult to judge. I had a set of figure 8 and epoxied a section of mm tape measure to the open end so that I could see how much the distance varied.
If you like the figure 8 you can make a set out of 1/4 plywood that work just as well.
https://www.woodturnerscatalog.com/p/86/...ti-Caliper

I prefer the single arm, rub the inside and watch the gap on the outside + or -. It's easy to watch the gap and the position of the calipers at the same time rather than looking at two points 17"? apart from each other.
These are similar to what I use. I epoxied a button on the inside arm to make sure it did not scratch the wood.
http://www.ebay.com/itm/Vintage-Starrett...isAAOSwwpdW3cTR

[AnthonyYak]

Somewhere close to a thousand HFs, I have no issues with them