Caliper

[Ken Higginbotham]

I bought one of these a couple weeks ago and really like using it. I do things like setting saw height on my table saw with it, etc. I can't imagine a more accurate, user friendly gizmo. I've abandoned every thing else like my tape measure and ruler for anything under 4-5 inches. Is this kinda what you pros use? I bought the $29 model but now that it has become so valuable I've considered buying a nicer one (if one exists)...

http://www.highlandwoodworking.com/ProductImages/markingmeasuring/065008.jpg

Link (http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=1047&HS=1)

[Rod Sheridan]

Hi Ken, I use a Mitutoyu digital which is nice since I'm slowly switching to metric in the shop. (It converts at the touch of a button).

I've stopped using it for planing though, my new planer is accurate to 0.07mm which is far more accuracy than I need.

Regards, Rod.

P.S. I often think however that we're too obsessed with accuracy when it come to wood. If you plane all the pieces at once, does it matter if your door rail and stiles are 20.0mm or 20.1mm? Especially when we then destroy all semblance of accuracy with a hand held random orbital sander.

[Ken Higginbotham]

I have a cheap digital version but I like the visual dial thing. And the green decimal scale makes head math a little easier...

[Brad Patch]

Ken

My cheap caliper is the best $30.00 I ever spent. They have many uses and make a great layout tool. You can spend well over $100.00 for a name brand, but for woodworking purposes I'm not convinced its necessary. I have a dial type graduated in thousands/inch. I'm familiar with decimal equivalents so its not a problem. However with just a little memorization one can learn the decimal equivalents down to sixteenths, beyond that I get out my equivalent chart . With the fractional version it seems to me that there maybe interpolation issues.

They are fragile and do not tolerate dust or trips to a cement floor.

[David G Baker]

I use metal gage blocks that are specific heights. Much easier for the lazy guys like me. The height is stamped on each one so no guessing involved. I frequently use a very cheap General Tool caliper that I don't worry about getting abused from excessive use. My good measureing tools I keep in their cases and in a tool cabinet and use them for metal working only.
I tend to agree with Brad about how much precision is needed in most woodworking but I am occasionally laughed at by carpenter friends when I work in 1/16 th's when measuring studs.

[Tom Esh]

I've been using them for over 30yrs. Indispensable IMO. My first was a Swiss - made fiberplastic job from Brookstone that did decimal, fractional, and metric - still in the toolbox. I guess the digitals are nice for conversion and and incremental, but I've really no use for yet another battery that needs to be replaced. I recently replaced a half dozen of the inexpensive (HF and others - all with various flaws) with a Starrett. Probably made in the same Asian factory as the others, but with much higher QC standards. Well worth the $70 or so.

[Thomas Canfield]

Ken,

Where did you buy the caliper? I noticed that it has the locking screw to set the dimension where my cheap caliper does not. The locking screw is a good feature for locking in a dimension for turning that I am looking for in the next cheap caliper.

[Ken Higginbotham]

Highland Hardware - I think the link below the picture will take you right to it.

Edit: Per the diagram below, I probably use the 'depth rod' more than the 'measuring contacts':

http://www.tpub.com/engine2/en2_files/image032.jpg

[Lee Schierer]

I had a dial caliper in my shop for a while. Saw dusat go into the gearing and made it jumpy and hard to work with. I bought a digital caliper from Harbor Freight for $12 and it has worked fine despite being dropped and covered in sawdust for several years now. Battery life is pretty good as long as you remember to turn it off when you lay it down and don't rely on the self timer to turn it off.

[Ed Labadie]

Many years ago I bought (for work) a Mitutoyo solar powered digital caliper. It's now in my shop & I wouldn't trade it for anything. It's so nice NEVER having to mess with batteries or issues related to them.

Ed

[John Thompson]

I bought my calipher like yours at Highland WW (then Hardware) years ago and use it daily to dimension lumber off the jointer and planer. I do use small brass blocks ground to tolerance by my BIL in his machine shop to set TS blade heights.

But.. I find the caliphers very valuable and they are quite accurate so I would not pay any extra for one as.... if it ain't broke.. don't try to fix it.

Ya neighbor on the other side of town...

Sarge..

[Bruce Page]

I wouldn't be without my pro-grade Brown & Sharp calipers. They're a bit more $$ but they are the best ones out there, bar none.
IMHO

[Ken Higginbotham]

Hi John,

Off Topic: Did you see the bs's on CL? what'd you think?

[Lance Norris]

I bought the $29 model but now that it has become so valuable I've considered buying a nicer one (if one exists)...

Starrett makes a fractional Caliper that is very nice. I have one and use it everytime i build something. It is invaluable when running the planer, even with a Wixey Digital Planer Gauge installed on my planer.

http://www.hartvilletool.com/product/12017

[Ken Higginbotham]

Starrett makes a fractional Caliper that is very nice. I have one and use it everytime i build something. It is invaluable when running the planer, even with a Wixey Digital Planer Gauge installed on my planer.

http://www.hartvilletool.com/product/12017

Thanks Lance - I've put that on my wish list. :)

[John Schreiber]

Do some calipers measure one revolution per inch and others 10 revolutions per inch? Mine has one revolution per inch and I'm wondering if there are other options.

I can make meaningful measurements down to within about .005, but to do it, I have to bring it to a bright light and/or a magnifying glass to read. Something where it's easier to see the small measures would be handy.

[Ken Higginbotham]

I think if they made it say 4 revs/in then you'd loose the precision on the other scale

[Myk Rian]

I repaired precision tools for over 20 years. 1 rev. per inch is the standard. Never saw one with 4 or 10per.
If you get sawdust in the rack, just take a straight pin and clean the teeth out. The pinion is a little trickier. Remove the bezel, (Usually pries up with a knife blade or thin screwdriver under the edge) hand (small needle nose pliers), and face. A jewelers Phillips screwdriver will remove the movement. Clean the pinion with a pin and put it all back together. Don't put too much pressure on the spring that holds the pinion. Just enough to make it track smooth. Put the hand back on at 0 then the bezel.

[glenn bradley]

I have a fractional one similar to yours in my drill bit drawer, a fractional one with an all white face (easier to read) in the top drawer under the workbench, a cheap digital with a magnet hot-glued on that sticks to the switchbox of my jointer, an expensive digital/fractional one that measures in 128ths and stays in a drawer because it is a pain to read (get one in 64ths like I bought for dad, JMHO), and a few of those $1 plastic ones from HF here and there about the shop.

[glenn bradley]

Something where it's easier to see the small measures would be handy.

Its called a digital display ;-)

[Bruce Page]

Do some calipers measure one revolution per inch and others 10 revolutions per inch? Mine has one revolution per inch and I'm wondering if there are other options.

I can make meaningful measurements down to within about .005, but to do it, I have to bring it to a bright light and/or a magnifying glass to read. Something where it's easier to see the small measures would be handy.
John, standard machinist decimal calipers move 10 revs per inch or 1 rev per .100, and are pretty easy to see .001 with. You can even split .001 depending on you analisity and eyesight...:o
The old Helios brand used to move .200 per rev. I never cared for those.

[Bruce Page]

I repaired precision tools for over 20 years. 1 rev. per inch is the standard. Never saw one with 4 or 10per.
If you get sawdust in the rack, just take a straight pin and clean the teeth out. The pinion is a little trickier. Remove the bezel, (Usually pries up with a knife blade or thin screwdriver under the edge) hand (small needle nose pliers), and face. A jewelers Phillips screwdriver will remove the movement. Clean the pinion with a pin and put it all back together. Don't put too much pressure on the spring that holds the pinion. Just enough to make it track smooth. Put the hand back on at 0 then the bezel.

:confused: Myk, Are we talking about the same thing? I have never seen machine shop grade, decimal calipers with 1 rev per inch and I have been around them for a long time.

[Myk Rian]

OK, take back. On a .001"/div. caliper, there are 10tpi. This one is 1tpi.
(http://www.starrett.com/download/61_120_caliper.pdf)

[george wilson]

It is best to lay the caliper face down when around anything that makes dust or small chips. This keeps tiny things from getting into the small rack gear,and into the very small gear that engages it. Not the best thing for the plastic lens,but just don't slide it around.

[Bruce Page]

Take this as an opinion of an ex-machinist, but I can’t see how the 1” per rev fractional calipers for “woodworkers” can be much more accurate than a tape measure. The rack & pinion would have to be very coarse.

[Scott Pearson]

My best suggestion - Buy a second one just like the first

Even the model that you have is more accurate then needed for woodworking the need to go a machinists level is really unneeded. I have had one for years and this year I got a second one because it always seemed to be on the other side of the bench when I wanted it, now I always have one in reach.

Scott

[Tom Esh]

Take this as an opinion of an ex-machinist, but I can’t see how the 1” per rev fractional calipers for “woodworkers” can be much more accurate than a tape measure. The rack & pinion would have to be very coarse.

1/100" is fairly easy to resolve on a typical 1"/rev dial caliper because even if the dial face is only 1" diameter, the outer scale is expanded about 50% more than a tape. I've not seen a tape with 1/64 or 1/100 graduations, but I wouldn't want to use it. Also with a tape you have the issue of hook slop and wear.

[Neal Clayton]

I bought one of these a couple weeks ago and really like using it. I do things like setting saw height on my table saw with it, etc. I can't imagine a more accurate, user friendly gizmo. I've abandoned every thing else like my tape measure and ruler for anything under 4-5 inches. Is this kinda what you pros use? I bought the $29 model but now that it has become so valuable I've considered buying a nicer one (if one exists)...



Link (http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=1047&HS=1)

i agree with scott, i don't think high dollar micrometers can add much benefit for wood. wood isn't that stable to begin with, 2 or 3 thousandths is plenty accurate, imo.

that said, yes, that's how you get perfectly matched joints. i don't measure height and depth with anything but a micrometer. when you cut a test board with a rail cutter and measure from top face to top of tenon and it says 0.500, that's it, cut away. visually with a square or ruler you might be able to get to 0.51 or 0.49, but past that it would be difficult to see...the human eye can't see variance that small. but a micrometer can and it doesn't lie. the result is joints that are perfectly matched, rather than looking perfectly matched but after feeling with your hand, need multiple sanding passes to be truly flush.

i use a digital one since i'm computer addicted, this (http://www.amazon.com/Carrera-Precision-Titanium-Digital-Micrometer/dp/B000QW6OGQ?&camp=212361&linkCode=wsw&tag=wwwnorthwinda-20&creative=380797) is the one i use.

[Ken Higginbotham]

Take this as an opinion of an ex-machinist, but I can’t see how the 1” per rev fractional calipers for “woodworkers” can be much more accurate than a tape measure. The rack & pinion would have to be very coarse.

After tinkering with both types here's my 2 cents: When we speak of the fractional caliper verses the machinist caliper from an accuracy perspective there is no comparison. A fractional is designed (by the single spin per inch) to measure in 64ths of an inch which is fine for woodworking. Whereas the machinist is in thousandths. So those options are 1 rev per inch, not precise enough, or the next logical option is 10 rev per inch which works very well.

Next about actually measure something - If I set up a cut requiring a 3/16 depth, and set it up 10 times, I bet I'd be a couple 64ths every time if I used something like a tape rule. With this caliper I have no doubt I can cut the error in half.

Maybe when I become more astute I can wing more but for now I need all the help I can get...