micrometer reading
- Thread starter DeanR
- Start date
The HF $35 micrometer got me looking into web reviews on it and it seems to be fairly accurate, comparable to the mitutoyo it was tested against. But one thing about it that's not obvious from looking at it is they made the bigger knob the ratcheting one, so its a lot easier to do a one hand measurement without having to reach too far to spin the (normally) little ratcheting knob way at the far end. Nice. Also, since the digital mics have an order of magnitude more resolution than I'll really need, if its not 100% dead accurate its still plenty good for what I'd use it for. It is a bit cheezy with the plastic knobs, but at $28 with the coupon, I might just pick one up and put my other 3 mics up on CL.
Also, regarding my earlier post about returning one of the Pittsburgh digital calipers because it didn't seem to be accurate enough, that was several years ago. I suspect the Chinese may have improved their accuracy over the last several years and the calipers might be better now than they were a few years ago.
Also, regarding my earlier post about returning one of the Pittsburgh digital calipers because it didn't seem to be accurate enough, that was several years ago. I suspect the Chinese may have improved their accuracy over the last several years and the calipers might be better now than they were a few years ago.
Ashley
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I picked up the HF digital micrometer today and it compares very favorably with my Mitutoyo in terms of accuracy. As I've gotten older I need to use a jeweler's loupe to read the 3rd vernier digit (0.001mm) on my Mitutoyo reliably. Measured a few valve shims and got similar readings down to .001mm resolution. Tried it on a few thicker items with similar results. I did notice that once the HF didn't return back to 0.000, it was 0.001 or 0.002, but it only did that once out of several times (the first time) that I returned it to zero. It doesn't have a high quality feel to it, but it seems to work OK, and for $28 I think its well worth the money for my usage model.
You have to keep the reading surfaces of the micrometer and the shim surface super clean. A very small grain of oil/dirt will read .001mm. I work at Michelin and use a digital micrometer daily. Also you get used to using the ratchet properly. Use the same pressure every time, do not use the un-ratchet part to get your reading...
link on how to use a micrometer
http://www.tresnainstrument.com/how_to_use_and_read_digital_micrometers.html
Hope this makes sense
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BakerBoy
It's all small stuff.
Td, what do you measure that requires 0.001mm (0.000039 in) accuracy?
I have worked at Michelin for 38 years next month. I work in the wire lab and we have tolerance of .001mm on some wire. The smallest wire that we measure is .09 mm with a tolerance of .002mm. We buy wire at 5.5mm and we have several finish wire. The smallest is .09mm and the largest is .35mm. We cable ~110t per day. We assemble wire for car tires to the earth mover 60in tire for the tar sands in Alberta and around the world. Michelin has been in our province since 1970. maybe to much information
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Yeah, I know how the ratchet mechanism works, how to keep the surfaces clean, etc. When the first zeroing attempt didn't go to 0.000 the first thing I did was clean the surfaces, but it didn't seem to help. Maybe I didn't clean it well enough though, that is possible given the tiny dimensions involved.
BakerBoy
It's all small stuff.
I didn't realize the fineness that went into tire wires, thanks.
Very interesting. No TMI. 38yrs at one job. 44 at mine. The day I left I happened to hear on the news that somebody entering the workforce now would have 5-6 jobs in their lifetime. Happy to have only two (although McDonald's doesn't really count).
Off by .001 or even 0.002mm isn't that big of a deal when measuring shims in my opinion
+1 especially since the error involved with my trying to read a mic would be much greater than 0.002mm.
In the service we were tasked to solve an equation. One of the guys in class had a state of the art calculating device— a slide rule. He worked at it and proudly proclaimed 'It's either 120 or 12,000!'
I'm bookmarking your link!
ya, I only applied because I got laid off at my current job which was a jack hammer operator. I actually lost money going to Michelin. I made 5.50/hr working 50-60 hrs per week to 5.25 working 40hr weeks. I was glad that I was still living home as my beer money got tight. BUT I am better off inside working. Some jobs almost killed me, holding my jack hammer above my head drilling out a basement windows... I will be retiring on April 1st 2020, 40yrs/60 years old or sooner... Plus I only called in sick once in those 38 years...
That sounds a lot like work! I knew a guy who worked construction and on a lark decided he wanted to try using an air hammer. An 'Hey hold my beer' moment. End result— both retinas permanently detached.Tdinova said:
I'm all for 40hr work weeks.
+1 on that, given that the feeler gauges and shims themselves are in increments of 0.025mm its an order of magnitude better than you can adjust anyway.
Once I re-zeroized that initial 0.002mm drift, several more trips back to zero all read 0.000. I didn't spend a lot of time analyzing what may have caused the original offset, given that it's a $28 micrometer I'm not surprised if it drifts a micron or two either way over time, so I was pretty happy with the fact that it didn't drift at all for most of the time I was using it.
Oh yes Michelin is very proud of the quality that goes into making tires. That's why they cost so much. Most single wire has a tol of 0.005mm. Several wires goes together to make a cable. We have very tight tolerances. Lots and lots of training is done before an operator is left alone.
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