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One of the things that I need to add to my reloading arsenal is a mircometer. Only problem is that I don't have much $ left to get one (that time of year).
I see that there's an enormous price range from very cheap to very expensive. Any suggestions on a conservately priced .0001 micrometer that would actually work?
Thanks,
Randy
I use this one from a local Harbor Freight store, and am quite happy with it. Its zero and measurements are consistent.
1 micron/0.05 thousands resolution and 4 microns/0.15 thousands accuracy are declared in the manual.
I have a Mitutoyo caliper and micrometer. Both are digital, not necessary,but nice to have. This brand has a reputation about as good as Brown&Sharpe or Starrett, but a little less money. They are still a little expensive, though. If you want to look at some that may be a little less money, go to Enco's website and see what they have. I have some older mikes made by Central Tool, I don't know if they are still around, but they were/are still good mikes.:D
I have a digital one that claims to read down to 0.00005" that I never use any more. It's Chinese and I got it from Midway.
Send me a check plus $5 for shipping and it's yours. Any reasonable offer accepted.
Got a Lyman from Midway. Chinese mfg. Same accuracy and identical measurement as a $125 Mitutoyo. Harbor Freight is good also.
You get what you pay for, and I am no way suggesting a Chinese Micrometer is as well mad or god as a Mitutoyo or Starrett. For my needs, a $24.95 Mic is fine.
Shiloh
I picked up a lyman at a gunshow for about $25. Seems to work good.
I picked up a digital at harbor freight for $9.00.
You can get a cheap China mic at some place like Harbor Freight for short money, but they are a bit hit or miss on the quality. Some are OK right out of the box. Some need a little fixing up, kind of like Lee-menting a mold. If you have the skills to tune up a mic, then you can probably do OK with one of those cheap ones. I keep one in my traveling tool kit & it's been doing OK for me now for a few years (after I tuned it up). I have my better mic's back at the shop. Even when they cheap ones are tuned up, they still don't have quite as good of a "feel" to them as the good ones do, but you can get good numbers off of them if you know how.
If you buy something like a Starrett, B&S, Mitutoyo, Fowler, or other name brand, then you are pretty much guaranteed to get a good one right out of the box, buy you will be paying RCBS prices for it.
That's about the best way that I can describe it to a boolit caster.
B&S is my favorite. Starrett is a very close second, but not their econo line. Fowler is right after that & tied with a few of the Swiss brands. Mitutoyo is not far behind. The stuff from China is not even in the same ballpark. The stuff from Poland is sort of in the middle.
I never heard of fixing up a micrometer. I thought that, unlike a mold, micrometer is a piece of precise mechanics, and any filing/polishing on the micrometer may not make it working better.
I use my calipers in my reloading room a lot more than the mic. I could probably get by nicely with just the calipers, but I kinda like using the mic slugging barrels, measuring boolit diameter. :lovebooli
I got a decent 1" Mic from sears ,I`ve had it for a while so price has probably gone up!!
My Rockford Arsenal $30 buck one has been takin a beating, and keeps on tickin
I've read in some reviews of different micrometers that they were'nt calibrated from the factory and the purchaser had to find a gage to zero them with... involved some disassembly in one case.
Is this the norm?
If the anvil is sprung theres ways of recalibrating it your self , but i think I would either send it for repairs or replace it .
The better gages will come with a check bar.
A 0-1" mic is self calibrating(for this purpose). If it doesn't read 0-0 when it's closed, just adjust the barrel slightly to align the 0-0 lines. With larger mics, you need micrometer standards or, preferably, gage blocks to set them. I have never seen an outside micrometer that required disassembly to properly zero. Depth micrometers may or may not require disassembly depending on the manufacturer. Starret depth mics as an example require each individual rod to be zeroed, which is a pain. If I remember correctly, Brown and Sharpe depth mic rods cannot be adjusted, and the micrometer itself is set just like an outside micrometer.
If you know what you're looking for and how to inspect a mic, pawn shops are good places to find mics in my experience. If you want to buy new, Mitutoyo is the least expensive and works just fine. Depending on what you intend to measure, you may also want a blade anvil mic and a ball anvil mic.
As far as I know, unless you buy a full 0-6" set of micrometers, the standards are not included.Quote:
Originally Posted by GP100man
Mic's are nice to have, but for reloading, all you really need is a set of calipers. I've got a couple nice Starret and Mitutoyo calipers, but the ones in my reloading drawer are a set of stainless-steel Harbor Freight made in China calipers that seem to hold the same as my Starrets, and they were less than $10.
Would I use them for checking surface finish on aircraft parts? Probably not. But for measuring if my .357 bullets drop at .358 or .359, they are perfect.
I bought a set of four mics from enco about 20 years ago. They are the chineese ones. They came in a wood case with three standards. They are very well made. I was an auto engine rebuilder at the time and assembled about 100 engines a year. I had to adjust one of them to zero when I first got the set. I used them daily for about 6 years without a hitch. They even have the plastic inserts to keep your hand from heating them and causing reading changes. I have used Tumico,Brown & Sharpe, and Starrett and these are as smooth and accurate as those. The set of four (0-4") were just under $100. You can usually find the 0-1" from enco or HF for less than $30. They read to .0001 and you can extrapolate another .00005 if you have good eyes. Although why you would need to dealing with boolits and loading, I don't know. These are the ones with solid stainless parts and carbide anvils not the ones with holes in the crane. For the loading bench, the dail calipers are probably more practicle. Even the cheap ones from HF work pretty good. Just be carefull with them as they are somewhat delicate.
It's a matter of getting it to move freely without introducing too much error into the screw.Quote:
Originally Posted by helg
First you do a bunch of gently & careful Lee-menting type work, sometimes to the screw, sometimes to the cylinder body, & then you check the mic against standards of known size at several different places in the screw's travel. You also measure cylinders at several different angles to see if the faces are flat & parallel. If you don't have actual standards, then Jo-blocks are a close second. If you don't have a set of (even "B" grade) Jo-blocks laying around, then dowel pins will get you within a few tenths. If you have nothing else, then buy a set of good quality drill bits & measure them when they are brand new. If all the readings come out good, then you should be all set. If you see variations of 3 or 4 tenths from what you expected, then you can probably only trust the mic to .0005" or so. A professsional Mic calibration will cost you more than a cheap mic. If you want something that will meet cal. spec., then buy a good one.
They also use what is called an "optical flat" to ensure that the measuring faces are flat and parallel. I have been tuning up micrometers since I was a kid in the 1970's and I do agree there is some tuning you can and should do on mikes.Quote:
Originally Posted by JIMinPHX
Bill
All that is true - but is also far overboard for anything you need to measure in reloading. Bullets fly, but they aren't the Space Shuttle.
I have a Midway caliper that I took out of its box the other day and the part that you adjust to get the reading literally fell apart in my hands. Like the metal disentegrated. I also use a harbor freight digital caliper and a Starret 0-1 mike. A shame about the Midway but what can you expect for $19.95?
The barrel is adjustable for a zero, much in the same way as a caliper. That's as much as there is to be adjusted. If the engraved calibrations are off, you'reQuote:
Originally Posted by helg
hosed.
Shiloh
Lufkin micrometer and starett dial indicator....I find both very necessary
You'd use a profilometer to check surface finish. ;)Quote:
Originally Posted by evan price
Jim has it right, just because it zeros dont mean its good. It could have worn threads in case of a used one or what is callled a drunken thread in case of a new one. Only you will know what is acceptable for you and most of them probalby be okay. For the cheaper ones I would look at the Fowlers.
Previous threads have discussed plug gages for measuring revolver throats. Why couldn't they be used to check accuracy of micrometers? I agree, if the threads are worn, zeroing against the anvil would not guarantee accuracy but checking several plug gage diameters should give an idea of repeatable accuracy. Just a thought and I may not know what I'm talking about.
John
W.TN
Even with a properly calibrated mic, I have never been able to get the correct measurement on a gage pin...the mic will normally read a couple tenths under the actual size.Quote:
Originally Posted by alamogunr
There is an adjustment that tightens the threads to allow for wear.
I was not aware of that. I got my micrometer when everyone wanted digital mics. Not having to use them regularly in my work, I was willing to take the old fashioned kind. Since they had an excess of them, I got to take it with me when I retired. It is a Brown & Sharpe. I guess I will have to read up on the adjustment.Quote:
Originally Posted by machinisttx
John
W.TN
I guess I would have to ask why you would need .0001 accuracy on a reloading bench? A case could easily squeeze a bullet that much just seating it. If you are really concerned about cost go with the HF mic. I have checked mine on pin guages and they are the same as my mitutoyo's. Maybe not quite as smooth but very repeatable.
I have a cheap Enco micrometer and a pretty good Mitutoyo. Both read the same when I measure things. The Enco cost about $6 on sale, the Mitutoyo was about $130. A cheap dial caliper costs about $20 anywhere tools are sold. Same for the cheap Chinese digitals. Look at 'em, they're all the same except for color of plastic on a few of 'em. All of 'em are good enough.
Too many people make perfect the enemy of good enough.
Gerry N.
You can.Quote:
Originally Posted by alamogunr
Are you using the friction thimble? Is the thimble working correctly?Quote:
Originally Posted by machinisttx
Even if the threads are worn, they are likely worn in a short area. So if you take the windage up there it will be to tight in the other areas. Just get a half way decent one with a vernier scale for .0001 places and it will most likely be accurate to .0005 depending on the user. I still stay away from the electronic just because I don't like to buy batteries.
I was all about getting a Starret 0-1 when found the RCBS with digital side display for $59.00.
After examining it, I saw that it had the 1/10 vernier and standard markings on the barrel and thimble. The digital reader is just an easy quick reference, so if it failed I could still use it like any regular old mic. All-in-all its pretty good quality. Even comes with the wrench to adjust for calibration if necesary.
No one needs to read tenths for boolit casting but, if you are going to spend the money.
Why not go for something that will do it all the way. You might have other applications come up in the future where you wished that you had the tenths scale.
I've used both ratchet and friction thimbles, mics properly calibrated and in perfect working order.Quote:
Originally Posted by JIMinPHX
How was the calibration done? Were the contact faces clean? Did you check to see if they were flat & parallel?Quote:
Originally Posted by machinisttx
I'm not trying to break your chops here. I'm just asking the ABC questions out of the gate because I don't know what your background is. If asking these questions to you is like asking a cabinet maker if he knows what a biscuit cutter is for, then I apologize.
My first job was in a toolroom making parts for both stamping dies and die cast molds. Typical tolerances were +/- .0002". I know how to use a mic. ;) Any gage block measured was right, but when measuring round objects..especially small diameter ones...the contact area is so small that it's easy for the thimble and anvil to move a couple extra tenths.Quote:
Originally Posted by JIMinPHX