I had the advantage of being exposed to my fathers farm shop from a young age and all the “goodies” there in! Priceless!
Three44s
I had the advantage of being exposed to my fathers farm shop from a young age and all the “goodies” there in! Priceless!
Three44s
Quote Originally Posted by Bret4207
“There is more to this than dumping lead in a hole.”
For some reason this thread has got me thinking about when I was learning to use a slide-rule a loooong time ago.
“Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem.” Ronald Reagan
It could well be that you're way over thinking this. How often do you need to make precise measurements to a precise standard?
I used to work at jobs that required frequent use of mics. In the most recent case, it was necessary to stay within a tolerance. In the former I was only comparing one thing to another thing (bore of inner race to the OD of a bearing journal).
Finnish grinding gimbals for ICBM's does require calibrated tools and a high level of proficiency. Comparing boolit OD to groove dia, not so much. Just sayin. YMMV.
You have enemies? Good. That means you've stood up for something, sometime in your life.
Winston Churchill
I teach myself everytime I need to use it by keeping a .308 jacketed bullet or a .452 jacketed .45 slug .
I reacquaint myself by taking a few minutes to enjoy mic' ing different known items.
Then it starts coming back.
Not a machinist by trade, just a mechanic and retired electrical construction worker.
I considered myself just a helper in life and wherever I worked.
Always trying to learn something new
A micrometer and a slide rule as well as a plumb Bob and a level.
A micro meter is just more fun.
You can learn it just measures things in tiny increments.
Each full turn is a part of an inch or a millimeter if you use a metric mic.
Man made, you can understand it by a little study and staying calm.
Enjoy!
Oh I forgot to add this:
get a set of feeler gauges and mic the different blades. That may help you to decipher the readings too!
Last edited by Alferd Packer; 05-25-2021 at 05:38 PM.
A good suggestion but with a cautionary tale.Oh I forgot to add this:
get a set of feeler gauges and mic the different blades. That may help you to decipher the readings too!
I have an older set of no name USA made feeler gauges (from the 70's I suppose). It was most likely a fluke thing but a couple years ago I discovered the .003" gauge was thicker than the .004". Long story short because I have forgotten many of the specifics, but two of the gauges between .001"-.004" were off and/or mismarked. I posted my discovery on one of the forums (don't recall which) and one of the experts assured me and the world I was an idiot who clearly did not know how to read a micrometer. Long story short I eventually cut them (.002"-.004") off and sent them to the expert. He got them and shared his findings on the forum. Two of the gauges were indeed bad. I still have the set, but minus those lower three gauges. I have no idea over the years how many times I checked the gap on something or another with those two faulty gauges, but ya just gotta wonder.
I guess the moral of the story is that even vintage "Made in the USA (no name) tools may or may not be equal to current day Chinesium products. Today, I double check my feeler gauges whenever I think it critical.
edit: found my post over on accurate shooter: https://forum.accurateshooter.com/th...4002033/page-2 After my having jumped through a ridiculous number of hoops post #40 results were:
so the 3 feelers showed up in the mail today.
measured both English and metric
marked .002 is .0037
marked .003 is .0053
marked .004 is .004
yep some really weird assembly in marking and putting together.
( do you want them back ??)
Last edited by oley55; 05-25-2021 at 09:22 PM.
“Some people spend an entire lifetime wondering if they made a difference in the world. But, the Marines don't have that problem.” Ronald Reagan
THAT is a great idea, even considering oley55's warning. I've got a complete set of those for "ancient" auto work, when an auto could be worked on under the shade of a tree.
[LATE NOTE: Almost forgot...I still use the feeler gages on the lawn mower to set the valve lash!]
Last edited by Land Owner; 05-30-2021 at 04:08 AM.
If it was easy, anybody could do it.
LO: Really this isn't that hard. You don't need to read tenths for 99% of your measurements. You can also just look at the position of the thimble in relation to the datum line and see where it is between the .001 marks. You can interpolate the tenths that way, and it is not that hard to call out 1 or 2 tenths over the last .001 mark or below the next mark. And is most cases it doesn't matter anyway.
The hardest thing about reading a Micrometer is learning how to add to the.025/ revolution marks because every time you must figure out how many Revolutions have gone by and then add what you see on the thimble to that. .025+.013=.038 .050+.023=.073 etc. Forget about the tenths!
The other hard thing is closing the thimble down on a part the same way every time.. You need to develop a feel for how much pressure you are putting on it as you clamp down on the part. Many Mikes have a clutch on the thimble that allows you to put the same pressure on closing every time. This is a good thing.
I have met some pretty stupid people in the Machine Shop Business. Some how they all figured out how to read a Micrometer.
You can too. It ain't that hard!
Randy
"It's not how well you do what you know how to do,,,It's how well you do what you DON'T know how to do!"
www.buchananprecisionmachine.com
I am a amateur Machinist..I rarely use Micrometers..Calipers are used 99% of the time. Sometimes I use Mics and cheat measuring the Micrometer with my Calipers.
I have picked up a LOT of information from this thread - including practice reading a micrometer. I have to spend some time with the feeler gages and the Chicom direct reading mic with its five (5) demarcation lines on the vernier instead of ten (10) as on the Starrett. I am feeling much better about reading the Starrett.
Thanks to all for replying and pointing me in the right direction. I'm an Old Dog but I still learn new tricks.
If it was easy, anybody could do it.
I have a couple micrometers but a good set of dial calipers are a lot easier to read/use to me and for what I use them for accurate enough. As I’ve said before ‘close enough for gov’ment work’.
when I first started in the trade dial calipers wernt considered accurate enough only vernier calipers ere used for anything other than .00 tolerances. I also remember inside jaws that started at .200. dials that were .200 per revolution. I have a set of Helios with both those features. Over time they got better then the digital s with glass or magnetic scales came out and again over the years they got better. Early ones coolant, oils and dust would have affects.
The basic micrometers design goes back 100s of years. It works now on the 40 tpi thread 1 rotation is .025. most have a take up for wear in the threads, a friction thimble or ratchet ( to lesson the feel factor). Major adjustments can be made on a joint with tapered joints on the thimble fine on the barrel.
Get yourself a set of automotive feeler gauges and star off by measuring some of those.
Then also look up a course online that can simplify what the readings indicate.
It's not hard once you get it broken down for you.
They had to make feet and inches smaller so they divided the inches into screw turns fine enough so there are forty real fine screw turns crowded together in one inch.
Thus, the one inch micrometer was born.The forty turns to the inch is further reduced to measure smaller than the fine thread turns.In between them except the measurement is first the number of those threads added to the distance between them, added to the measurement you have accumulated to this point.
If you try what I have suggested and follow it a step at a time you will see that any measurement with a vernier is a sum of units, tenths, hundredths, thousandths, and finally ten thousandths.
You merely learn to read a d add together the measurements same as you do on a folding six foot ruler.
They are all just divided measuring sticks that are read the way their maker laid them out.
A vernier caliper just takes practice and repetition to learn and remember
You may find yourself reteaching yourself to read the caliper if you don't use it all the time.
Mike the page in a book, Mike a piece of wire mike a lead pencil diameter.
I mike bullets, cast and jacketed.
Gun barrels and screws, nuts and bolts and drill bits as well as metal thickness as the neck of a cartridge case.
Get a set of feeler gauges .The size is etched on them
Good Luck.
My thought is the same as Randy Buchanan’s. You really don’t need better than .001 accuracy for casting and reloading. Forget the tenths vernier.
Sometimes life taps you on the shoulder and reminds you it's a one way street. Jim Morris
I learned how to read a vernier from machinists when I was working as a manufacturing engineer. I've got B&S and Mitutoyo mics, Mitutoyo calipers. If I happen to post something that is usually measured with the micrometer, I use the vernier for the 4th position so I don't get accused of using the caliper.
The post mentioning using the slide rule got me thinking that when I was in college most of us usually just guessed at the last digit. After awhile you get sort of good at it.
John
W.TN
Knowing how to read vernier scale type tools, allows you another punch on your "Man Card". jd
It seems that people who do almost nothing, often complain loudly when it's time to do it.
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