I got a micrometer

[frkelly74]

I went to the old Harbor Freight store in Kalamazoo yesterday and saw that the 1" mic was on sale for $18.99 so I got one. As a caution to anyone reading, I will say do not buy the first one on top of the pile. As a matter of fact I opened and looked at the first two and both had been opened and played with and the gear that runs the odometer like readout was stripped and not reading correctly and grinding. I almost gave up at that point but the third one was unmolested and did not make the grinding noise. granted that you can still measure without the " odometer" but it is nice to have things right to start out.

So I went on a measuring binge when I got it home and discovered that my 308 311 323 and 452 lee push through dies all size about .0003" over size which is good news to me, the 285 sizer is on the money, But the 243 that I drilled out to try to make a 266 is 269 X 267 which I kind of knew but it is good to have it confirmed. For some reason they still shoot pretty well in the 6.5 Rob. I will have to run that experiment again some time.

next I will be casting some bullets to see what they drop at and I will try slugging some bores and maybe I can start to get good results on purpose rather than by accident once in a while. I expect a lot of the Mystery of casting will go away.

[snuffy]

So, did you get a micrometer, or a caliper? OIC, I just re-read your OP, is it a digital read-out mic?

I guess my question would be how did you do anything without a means to measure before buying that mic? Just guess?

Using a micrometer is an art. How tightly you turn the thimble can affect the readings. Most have a drag knob on the extreme end that puts the same "feel" on the thimble for consistent readings.

[oldhickory]

Keep it clean and a mic. will tell you the dia. of your boolits closer than a caliper will. Be gentle with it though, in order to maintain true readings.

[R.M.]

Is there a manual with it?
Does it read zero when closed up? Sometimes they need to be adjusted/zero'd.

[geargnasher]

All the "good" 0-1" mic's come with a calibrating block at 1.000" and, obviously, the "zero" is checked with thimble tension on closed jaws. Be careful when holding the tool, only touch it on the insulator pad at the backof the "C" part since body heat will quickly distort a room temperature mic a thousandth or two. Probably not as good as a Starret, Mitutoyo, or Brown & Sharpe, but plenty good for your cast boolit measuring, and much, much better than even top quality calipers.

Gear

Gear

[frkelly74]

How did I get along? Answer, I believed whatever the published literature or the markings on the equipment said, and the seat of the pants so to speak. My results have been hit or miss. ( literally )

the odometer is gear driven and apparently fragile. It also has the scribe marks on the shaft so it will work without the odometer>

I already found out that lube on the anvil has a measurement.

There were instructions . But they were very rudimentary, mostly concerned with warranty information.

It does have a ratchet thimble that doesn't allow you to close it too hard, if you use it.

It reads zero if there is no lube on the anvil.

I am glad to find out about the plastic insulator. I did not realize that that was what it was or that it had a function.

It was made in China and is a cheapo. I will see how it does

[geargnasher]

A Mitutoyo will read fingerprints on the anvils. About .0002". But they cost five times as much.

Gear

[snuffy]

It must be like this then. This is both digital and has the markings for normal use.

http://media.midwayusa.com/ProductImages/Large/897310.jpg


It should work just fine for you. Some of the fancier digitals are electronic.

The one I use has .0001 increment possibility. Nice to have when measuring case head expansion.

[frkelly74]

Bingo

[JonB_in_Glencoe]

Frank,
just an FYI.
I have one of those China mechanical Digital 0-1" mic.
after about a weeks worth of use, it started grinding.
I took the cover off the digital counter, there are two small screws inside
holding one gear against the other,
they were loose and the gears were skipping. No major damage,
I closed the measuring anvil, then I adjusted the counter to 0.000,
applied a tiny bit of light oil, alligned the gears and tightened the screws,
then replaced the cover...No big deal.
I just thought I'd mention this in case yours does the same thing, the one's
in the store were probably not damaged, just loosened from the long boat ride here :)
Jon

[JonB_in_Glencoe]

Be careful when holding the tool, only touch it on the insulator pad at the backof the "C" part since body heat will quickly distort a room temperature mic a thousandth or two. Gear

Really ? that much ?
or did you mean a ten thousandth or two ?
Jon

[softpoint]

I have a Mitutoyo 1" mike that reads to a hundred thousandth, and it is amazing what even a fiber from a cleaning cloth that you can't even see without a magnifier will measure. Way more accurate than what I need, but was given to me as a gift.:drinks:

[geargnasher]

Really ? that much ?
or did you mean a ten thousandth or two ?
Jon

Nope, I mean a thousanth or two, .001-2". Try it. take a measurement at 70* and then hold the mic so your fingers touch the corners of the arbor, hold for at least a minute. Recheck your measurement. My Fowler 2" will change .002" if you hold it wrong on a cold morning.

Gear

[frkelly74]

Good to know Gear. Those first two sure felt broke..

Hey Jon, Are we havin' fun?

[JonB_in_Glencoe]

Frank,
yep...having fun.
I am only guessing about what was with those at your HF store.
I thought mine was shot before I opened it up.

Gear,
thanks for clarifying, I'm going to dig out my standard and try it.

Jon
Jon

[Shiloh]

Good investment.

Mine is Chinese, less than $25, and measures exaxtly the same as a $125 Japanese Mitotoyo micrometer.

Calipers are fine for general measuring, case length, basic boolit diameter, crimp size ect.
But when you really need to know...a mike will shine.

Shiloh

[white eagle]

buying good quality measuring instruments will pay off far better than having to hold one leg in the air to get a good reading
congrats on the mic

[dicko]

Good investment.

Mine is Chinese, less than $25, and measures exaxtly the same as a $125 Japanese Mitotoyo micrometer.

Shiloh

Yeah, that's about right. I have a bunch of mikes, use 'em for reloading, gunsmithing and machining. I have Mitutoyo, Brown & Sharpe, Moore and Wright, all top makes, and a couple of Chinese. The Chinese mikes are just as accurate. The only difference is that the quality makes have a certain free running smoothness that the Chinese mikes lack. They are slightly "stiffer" running. But it is a small thing and they are every bit as accurate at a fraction of the price. Same goes for vernier calipers.

[Centaur 1]

Yeah, that's about right. I have a bunch of mikes, use 'em for reloading, gunsmithing and machining. I have Mitutoyo, Brown & Sharpe, Moore and Wright, all top makes, and a couple of Chinese. The Chinese mikes are just as accurate. The only difference is that the quality makes have a certain free running smoothness that the Chinese mikes lack. They are slightly "stiffer" running. But it is a small thing and they are every bit as accurate at a fraction of the price. Same goes for vernier calipers.

That is so true, even Browne and Sharpe has changed over the years. The one that I purchased in 1978 when I started my apprenticeship is ten times smoother that the one I acquired in the mid 80's. I hate to say it Gear, but if your Fowler changes .002" by holding wrong, then it's time to get a different brand. Fowler is a perfect example of a company with a quality reputation, going downhill to try and stay in business.

[geargnasher]

The issue with the Fowler mic set I have is that the arbor is aluminum, not steel. Aluminum as you know has a much higher coefficient of thermal expansion than forged steel, plus this mic has a very wide arbor shank, so if you heat the outside corners with your fingers the measurement at the anvils shrinks as the metal warps. This is true with any c-clamp mic, but not usually so drastic.

Gear

[JonB_in_Glencoe]

Gear,
thanks for making me check my mic's
I have an new apreciation for the China mech. Digital Mic.
the end of the arbor that has the housing for the digital readout is massive,
I think that helps with heat change...Plus they have an enamal/porcelian/paint coating.

I have 4 mics
I measured a 1" standard
the room temp in my reloading room is 61º F.
Then, I held both ends of the arbor with both hands on the uninsulated area, for one minute
I measured the 1" standard again.

China Mic #1 (insulated arbor)
first measurement: 1.0007
second Measurement: 1.0007

China Mic #2 (insulated arbor)
first measurement: 1.0002
second Measurement: 1.0003

Craftsman Mic (USA made, Stainless steel, 40+ years old, non-insulated arbor)
first measurement: 0.9997
second Measurement: 09995

Starrett Mic (USA made, 70+ years old, non-insulated arbor)
first measurement: 1.000
second Measurement: 1.000

the Starrett isn't capable to read ten thousandths, if I were to guess at the space
between the graduations, I would have said...
first measurement: 1.0003
second Measurement: 1.0003

If I buy another Mic, I'll look for the aluminum construction and avoid it !!!
thanks again,
Jon

[Centaur 1]

The issue with the Fowler mic set I have is that the arbor is aluminum, not steel. Aluminum as you know has a much higher coefficient of thermal expansion than forged steel, plus this mic has a very wide arbor shank, so if you heat the outside corners with your fingers the measurement at the anvils shrinks as the metal warps. This is true with any c-clamp mic, but not usually so drastic.

Gear

WOW, an aluminum micrometer, I didn't even know that such a thing existed. I'm a retired tool and die maker, so I believe in buying quality tools. An aluminum mic has no place in a machine shop. I know that when it comes to measuring boolits that you don't need the type of tools that I own, but there are limits to what is acceptable. I see guys bashing calipers on here all the time, so maybe they're getting a bad rap if they're made as cheap as that mic. My calipers are good to .0005 and I'd stake my reputation on my measurements taken with them, but they also retail for over $200. Anytime I've ever measured the I.D. of a barrel with my calipers, I've always gotten the same measurement when I slugged the barrel. A lot of that is technique and knowing how to keep the slide of the caliper tightened properly. For everyday measuring I also have a harbor freight 4" caliper handy, but I don't have to worry about knocking it to the floor or spilling beeswax on it either.

[rbuck351]

I have a set of four Chineese mics 1"- 4" graduated to .0001 and after first adjusting them about twenty tears ago they have always read right where they are supposed to. They came with three stds and everything has been top notch with them. They are very smooth and the ratchets work with very light drag. I have used Starretts, Brown and Sharps, Schere-Tumicos and other quality mics and would put these China mics up with any others I have used. I Paid about $100 for these and have seen other China mics that are not as good. Most any mic is going to be better than you really need for reloading or casting.

[Bret4207]

WOW, an aluminum micrometer, I didn't even know that such a thing existed. I'm a retired tool and die maker, so I believe in buying quality tools. An aluminum mic has no place in a machine shop. I know that when it comes to measuring boolits that you don't need the type of tools that I own, but there are limits to what is acceptable. I see guys bashing calipers on here all the time, so maybe they're getting a bad rap if they're made as cheap as that mic. My calipers are good to .0005 and I'd stake my reputation on my measurements taken with them, but they also retail for over $200. Anytime I've ever measured the I.D. of a barrel with my calipers, I've always gotten the same measurement when I slugged the barrel. A lot of that is technique and knowing how to keep the slide of the caliper tightened properly. For everyday measuring I also have a harbor freight 4" caliper handy, but I don't have to worry about knocking it to the floor or spilling beeswax on it either.

I think that's the key right there. I can recall in my ham handed stage when I thought I was supposed to crank down on my measuring tools. Not good! At that I wonder how much difference there is between users of the same instrument. Both use the friction thimble but one "spins it into the work", the other brings it slowly into contact. You'll get 2 different measurements that way.

Lot's of variation depending on technique. Consistency is very important.

[Bill*]

Don't store the mic with the anvils closed (touching). Cant remember why but I was told that by a T&D journeyman 40 years ago. I also used to ever so gently close it on a piece of clean white paper and draw (slip) the paper out to clean the anvils before opening it back up a bit and returning it to the box

[HORNET]

If you store the mic with it closed, temperature changes can cause uneven expansion/contraction that could spring the frame. Not good.
If you don't like the aluminum mics, you ought to see the 1/2" capacity one that I have with a die-cast zinc frame. I don't trust it much for obvious reasons. I have no idea where or when my dad got it.