Low Cost Digital Micrometers

If you are making a product that requires +- .0001 accuracy why even consider "cheap"? Tenth reading mechanical micrometers produced by Starrett, Mitutoyo and Brown and Sharpe are perfectly suited for this purpose, regardless of whether using digital or mechanical tools gauge blocks of .0001 accuracy or better will be required.

After looking at the picture of your product I can not imagine how one may hold these numbers in such materials, all I can say is good luck.
 
Hello Tom, Martin, and Bob,

A glue-up in woodworking is just an assembly held together with glue. I use WEST epoxy and Hot Stuff cyanoacrylate in my rosettes---no water. I meant that I'm always working with a glue-up of slats of some sort, not with the .020" squares.

The Harbor Fright micrometer looks likely---I'll have a look at the link. The reason for wanting a low cost mic is summed up in this one-liner: "To get a guitar-maker off your front porch, pay him for the pizza".

As for holding tolerances to a tenth in wood, the first trick is a humidity controlled atmosphere. The second trick is a remarkably accurate scraping tool. And it is certainly the most technically demanding thing I have done in over 50 years of woodworking. I can assemble some .pdf's of the process if anyone is interested. I teach guitar-making on a one-to-one basis, and I really need some notes on rosette making for my students.

And to answer an un-asked question, no the old time Spanish guitar makers didn't work to tenths! They would design the patterns to hide errors, or use other tricks. I told my old mentor, Gene Clark, that I made Spanish guitars like a German, and then corrected myself by saying "more like a German machinist!"

Cheers,

And to Martin 73---I looked you up on QRZ

Brian Ex: W5BRO, K6UCD
 
I've always considered calipers to be a measuring tool that is used when accuracy isn't critical. I have never heard of anyone working to tenths with one. I have a few name brand calipers that I use, but when I have to hold a tolerance I use a mic.
 
Hello Chuck,

Exactly! That's why I was inquiring about mic's. I did my last batch of rosettes using an old Sears mic that read in tenths by using a vernier on the barrel. I then managed to tighten it up too much in an effort to take the backlash out of it---no dice, it's stuck tight. Also it's a bit hard to read for a 76 year old that doesn't see as well as he used to.

Cheers,

Brian
 
I've got one of the HF 68305 mic's pictured above and find it works well. I've checked it against my old gauge blocks and have no complaints about accuracy or repeatability. Battery lasts a long time and the display is quite readable. Good value for the price.

I have a B&S micromaster electronic mic which had a nicer feel but the electronics died and B&S no longer repair them so the HF is its replacement.

John
 
BrianBurns said:
Hello Chuck,

Exactly! That's why I was inquiring about mic's. I did my last batch of rosettes using an old Sears mic that read in tenths by using a vernier on the barrel. I then managed to tighten it up too much in an effort to take the backlash out of it---no dice, it's stuck tight. Also it's a bit hard to read for a 76 year old that doesn't see as well as he used to.

Cheers,

Brian
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Brian, somehow I got the idea that you were looking for a caliper. I also had a craftsman mic that I bought back in the 80s. It was my go to 1" mic....until I dropped it a couple of months ago. I replaced it with a mitutoyo that just doesn't feel the same. I have one digital mic. Its a 2" mitutoyo. The battery is dead and I just use a regular dial mic instead. You're correct about the digital being easier to read though. My eyesight leaves something to be desired also. I have no experience with the real cheap digital mics so I can't speak to that. Probably a crap shoot.
 
I have one of the harbor freight ones its always measured within .0005 of my very expensive mityotoyo. It's just fine.
 
I've seen several posts mentioning how hard it is for old eyes to read regular micrometers. I do agree.

My solution has been to get a couple of pairs of bifocal safety glasses that are 2x and 3x power. The 2x are what I regularly wear in the shop. They're useful for a lot of things.
 
Hello Charles,

When I worked at the Stanford Microwave Lab in the late 1950's the machinists were all wearing Optivisors. I've tried the cheaper versions, and have gone back to the Optivisor brand because they have better quality optics. I have 3X, 5X, and 10X, and go around the shop almost all day with the 3X on. At somewhere around $30 apiece, they are quite a bit less expensive than prescription glasses. They flip down over my prescription glasses, and flip up out of the way when I don't want the magnification. And you can get replacement parts and other powers of lenses.

Cheers,

Brian
 
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