Are these cheap 0.02mm/m Chinese level vials really accurate?

[DMF_TomB]

I was amazed to see “high precision” level vials sold in Aliexpress, rated with 0.02mm/m resolution (twice more sensitive than a Starrett master precision level). They are sold for about 13 bucks. Any experience with thoose?

I’m not a big fan of cheap tools, more out of curiosity.

Aviv.

easy to test if 0.02mm/m and level is 200mm long, 5 increment is 0.1mm/m or 0.02mm/200mm
5 increment is 0.0008" per 8" roughly
.0025" feeler gage under one end and .0024" (2ea .03mm) under other end.
basically it reads off scale most times, it for scraping surfaces for waves or high spots. mine
passed calibration testing but
.
picture of $20. square frame level I added a Starrett .005/12" or .004"/10" (0.4mm/m) vial to it,
brass knob squeezes (40tpi ? screw I forget what screw I made) Oring spring to calibrate so same
reading when level 180 degree. I added cause the 0.02mm/m vial usually reads off scale.
the less sensitive vial needs to be used to 1/5 of a increment to read 4 lines off on the sensitive vial
.
usually a 0.05mm/m vial is more expensive than a 0.02mm/m vial I believe
the Shiyong Wujin Shouce (Standard Hardware Handbook) list levels from
0.01mm/m to 0.10mm/m
standard GB/T 16455-1996
my handbook is 25 years old, out of date of current standard most likely

 

[DMF_TomB]

I was amazed to see “high precision” level vials sold in Aliexpress, rated with 0.02mm/m resolution (twice more sensitive than a Starrett master precision level). They are sold for about 13 bucks. Any experience with thoose?

I’m not a big fan of cheap tools, more out of curiosity.

Aviv.

one level i had a problem with as shown it was rtv glued to grooved metal piece and glue failed one
end thus the rubber band, obviously can clean and glue it with rtv again.
.... i added a fine adjust to it as shown, the basic unmodified design is fairly standardized, putting
florescent paper under vial, or painting bottom of vial with 1/2 florescent paint 1/2 glow in the
dark paint when flashlight used a few seconds it glows awhile to easily see level vial for
quite a awhile. still most times those levels are too sensitive they only used when less sensitve
levels show it's perfectly level.
aluminum low profile level I made (I bought the vials from some surplus place), aluminum
casting has some porosity I overheated the aluminum in my foundry furnace. obviously
make your own level if you think you can do better than the $20. Chinese levels
PS the 127tpi screw has a split brass nut to adjust tightness on screw, the threads so
fine they look like a rough turned lathe part not a screw. I had to make the tap too.
made about 23 years ago I forget exactly when I made the aluminum low profile level

 

[DMF_TomB]

I was amazed to see “high precision” level vials sold in Aliexpress, rated with 0.02mm/m resolution (twice more sensitive than a Starrett master precision level). They are sold for about 13 bucks. Any experience with thoose?

I’m not a big fan of cheap tools, more out of curiosity.

Aviv.

Web Conveyance roll level I made can hold on bottom, top or side of a cylindrical roller.
0.004"/10" increment level vial, held plastic tipped set screws has room for led light
aluminum so light weight less likely to scratch roller with mirror finish
.
make your own precision levels if you want a "special" design

 

[gbent]

Emgo, how do you square up a boring mill without a couple of precision levels? How do you take the twist out of a long lathe so you don't chase your tail adjusting the tailstock for every different position? Its way faster to set up a long part in a steady rest if the lathe is leveled rather than playing with your dick stroking the part with indicators.

 

[EmGo]

Emgo, how do you square up a boring mill without a couple of precision levels?

I can go look, but pretty sure I never said that levels were silly. What's silly is this stuff about "accuracy". The damn things are a bent tube with an air bubble. What are we talking about, the distance between the marks ? That part is ridiculous. Asking "is this level precision ?" is like asking how chocolate is a chocolate cake ?

There's too many people obsessing over silly shit, was the point.

 

[Donkey Hotey]

What are we talking about, the distance between the marks ? That part is ridiculous. Asking "is this level precision ?" is like asking how chocolate is a chocolate cake ?

Maybe this is why you don't believe I can hit a tenth or two with a Haas on diameters? I do sweat this stuff and it does make a difference.

 

[EmGo]

I agree with you in principle but, the sensitivity of the vial is what's in question. Common construction levels will show that air bubble as dead center where the precision level will still show the variance. I know you know this and not sure why you want to argue.

Because of this whole stupid hobby-shop "accuracy" crap. The people who want a "new, quality 120" lathe that's "accurate !" to .0001 or .0003 .... the people who can't figure out how to make a three-phase motor turn the other way "why didn't you buy something with factory support ?" ... it's like a group of highly-educated theologians arguing about how many angels can dance on the head of a pin. It's stupid.

In reality that carpenter's level is just as "accurate". It's a bubble in a bent tube. If your eyes are good enough, and your binocular eyes can both get exactly normal to the arc of the vial, and you can distinguish the exact point where the arc of the meniscus is tangent to some arbitrary location on the tube, it is in fact all the same. Pretty soon we'll be hearing about the top-grade levels that use pure nitrogen instead of air, "it's more accurate !"

None of this silliness matters because no machine tool that's bigger than a foot long is ever totally level, and even if you did get it that way it wouldn't stay longer than an hour, and even if that happened it wouldn't matter because the whole reason for levelling is to try to replicate the conditions the piece was initially machined at, but the damn materials have changed shape since then with a 99% probability and this talk of .0002" twist is equally silly, so ... beyond a certain point, all this is, is pulling on your dick.

This is supposed to be practical machinist. It says so at the top. Beyond "hey, this is a nice level, convenient size, clear markings, nicely made and feels good" we're just being silly.

 

[EmGo]

Maybe this is why you don't believe I can hit a tenth or two with a Haas on diameters? I do sweat this stuff and it does make a difference.

Bullshit. A fucking sl3 mori will not do that. You're deceiving yourself. A goddamned landis grinder has to be in real good shape properly operated to do that. Sorry, that's reality.

You are talking bores on a Haas TL-whatever, if I remember right. I have ground bores on a Heald ID grinder. A lot of them, days at a time. The bores ended up as outer races for roller bearings. They had to be one to three tenths on roundness and size. Had to be, they were bearings. We were reasonably assiduous on temperatures, coolant temps, measuring equipment, quality bore gauges set with ring gauges and so on. Not fanatics, these weren't aircraft turbines but still, pretty careful.

A Heald i.d. grinder is about 10,000 lbs. The table is probably 1,500 lbs. The spindles turn 12,500 or 15,000 depending on the bore size. They have abec 9 bearings, a rebuild was a couple grand back in 1970. The handwheel for incrementing the cross slide had five divisions per tenth ? Or maybe just two ? Anyway, the wheel was at least 12" in diameter, the divisions were 3/16" apart or more ? Sharply engraved and very readable. And the ratchet that fed the wheel took several clicks per division. The bearing area for that table was five feet long ? Hydraulically actuated, very smooth in operation. You'd turn the thing on in the morning, temp-controlled room and let it all cycle for a half hour before you even indicated in the first part, with a 1 1/2" dial alina tenths indicator. The wheel always touched in three places on first contact, where the chuck jaws had held the blank when turning it. Just that chuck pressure caused maybe a thousandth of out-of-round. You'd grind to two thou away then dress. Then grind to one thou away and check the bore. Grind to two tenths away, retract, measure and adjust your infeed setting. Grind to a tenth away and check. Finish grind. There are stops on the table speed handle, so you can kick the speed to the exact same place after a rapid retract and return. Stroke speed changed size. Flood coolant like niagara falls with a twenty gallon reservoir. Seriously, we'd dream of being on the beach in tahiti while the table went back and forth.

Doing all this shit, it was hard work holding one to three tenths on diameter.

This is why I do not believe your haas lathe is "holding tenths".

btw, since you mentioned fork tubes - came across this last year, what is this weird thing ? Ha ! Special machine for boring bicycle / motorcycle forks ! Kind of cool. It's not really about "low cost labor" ...



(And since nothing on it is horizontal, they probably don't set it up with a level, ha ha )

 

[Donkey Hotey]

In reality that carpenter's level is just as "accurate". It's a bubble in a bent tube. If your eyes are good enough, and your binocular eyes can both get exactly normal to the arc of the vial, and you can distinguish the exact point where the arc of the meniscus is tangent to some arbitrary location on the tube, it is in fact all the same.

Yes, except I do that with the 0.0005" graduations and split them as much as I can. That yields even better readings.

None of this silliness matters because no machine tool that's bigger than a foot long is ever totally level, and even if you did get it that way it wouldn't stay longer than an hour, and even if that happened it wouldn't matter

The guy who installed my VF-2 did a damned thorough job. Almost 20 years ago now. I checked it six months ago and it's still well within 0.001" corner to corner.

because the whole reason for levelling is to try to replicate the conditions the piece was initially machined at, but the damn materials have changed shape since then with a 99% probability and this talk of .0002" twist is equally silly, so ...

If you're quoting my earlier post there, you're off by a decimal. My lathe is twisted 0.0025". Two-and-a-half thou. Not happy but, their tolerance is 1 per foot. The machine sat on three legs and the fourth only lightly contacted for 15 years. It didn't move. I hoped the casting would unwind but, it's still what it left the factory with. I now have an anchor kit and one of these days, I'm clamping the two corners down to get that out of it.

This is supposed to be practical machinist. It says so at the top. Beyond "hey, this is a nice level, convenient size, clear markings, nicely made and feels good" we're just being silly.

Back on the subject of the levels, yeah, if these vials are set up to be used in the precision realm, I think it's a worthy subject. It was maybe a month ago, somebody was trying to find a replacement vial for a Mitutoyo precision level and it's no longer available. Maybe one of these could save it?

Heck, this got me looking at the whole levels they sell with (presumably) this vial. I wouldn't mind having a second precision level to have one in each direction and not constantly rotating one and waiting for the bubble to stabilize. Do the final check with a single unit. How's that for gratuitous overkill?

 

[Donkey Hotey]

Bullshit. A fucking sl3 mori will not do that. You're deceiving yourself. A goddamned landis grinder has to be in real good shape properly operated to do that. Sorry, that's reality.

I mentioned this before: I reline transmission bearings where the total clearance is 0.0012-0.0015" range. 0.002"-0.003" or more is what I'm trying to correct by relining them. Not sure why this is so hard to believe. You can feel the change in fit between the snug or loose side of the target range. It's motorcycle transmissions. Nothing you haven't seen a hundred times yourself.

 

[EmGo]

It's motorcycle transmissions. Nothing you haven't seen a hundred times yourself.

I know that when I first started messing with my own bike, I tried to make things wonderful, perfect and tight tolerances. Then I went to the racing grounds (tell laura i love her) and found out that in use, all this shit changes shape and tightens up. After a year or two of making things looser and looser and looser, they finally started to live and not seize up in use.

That was before they used billiard tables for race tracks tho. Too tight never did work on a flat track, they have bumps.

Same was true of midgets.

After all these years, now I know why the bore on third gear would come back blue (too tight) If he'd seen that he'da had more than a few doubts about mistreating that lovely gearbox

Richard Schlacter,Ontario,Ducati, Salvisberg

 

[Donkey Hotey]

I know that when I first started messing with my own bike, I tried to make things wonderful, perfect and tight tolerances.

This was a factory recall on Yamaha XV1600s and should have been on Excelsior-Henderson Super-Xs. The Japanese transmission manufacturer messed up on some of the transmissions, delivering them with really sloppy bearing clearances.

The result on those bikes was the gears would wobble, which walked the circlips out of the grooves. Once that happened, the gears were free to slide around. This eventually locks the rear wheel.

How much clearance is acceptable before it fails? That was never communicated. Yamahas got new transmission gears under the recall. Excelsior-Hendersons get what I do: take them down to the bottom of the range and substitute spiral clips for the regular circlips while you're in there.

 

[EPAIII]

I must admit that EmGo has a point. But I am not ready to go all the way with him.

The first thing I have found is if you are trying to level beyond what your floor can support without changing when you walk around or when a truck drives past the shop, then you are into useless accuracy. Wood floors, of course, are the worst. But concrete can also move under stress.

The next thing is if your machine is allowed to move about on the floor, EVEN A FRACTION OF AN INCH OR A FEW MM, then you may as well just use a carpenter's level. Concrete is NOT FLAT.

Then there is putting the level on the ways. Vee ways have a flat on top. And most people just put the level on that flat. But is that flat scraped in to be parallel to the other surfaces? And are there any dings on it? We are talking tenths here so even a very slight ding can throw things way off.

The last thing that I have learned is the "leveling" instructions for a lathe end with taking test cuts and further tweaking until they are as accurate as you want/need. So I ask myself, just how accurate does the leveling need to be before you proceed to this LAST STEP?

I have an import, master level. It is supposed to be in the same league as the Starretts and other high quality master machinist's levels. I have never had my lathe on a floor that allowed me to check on that claim. And I haven't used it in years: it is sitting on a shelf in it's nice case.

My point is, you can't just slap a level on the ways of a lathe and expect superb accuracy. You must look into the whole process. And stop when you reach a point where the lathe is good enough for the work you are doing. So yes, IMHO, EmGo has a point.

 

[EmGo]

But I am not ready to go all the way with him.

Thank God for small favors

 

[Bill D]

Emgo my understanding is it is a straight tube. It is ground inside to a barrel shape. the radius of the barrel determines the vials sensitivity. There is no top or bottom, unlike a horseshoe shaped vial.
BilL D

 

[John Garner]

For those who are interested in learning more about the types of level vials, a visit to www.wamoyer.com is worth a few minutes of your time

 

[avivz]

Does anyone actually use the graduations to accurately measure slope?
At least in the scope of machine rebuilding / machines setup, I always thought that these are used in a comparative manner to compare different areas on the machine. Does anyone use precision level as an alternative to a sine bar for instance?

 

[avivz]

I must admit that EmGo has a point. But I am not ready to go all the way with him.

The first thing I have found is if you are trying to level beyond what your floor can support without changing when you walk around or when a truck drives past the shop, then you are into useless accuracy. Wood floors, of course, are the worst. But concrete can also move under stress.

The next thing is if your machine is allowed to move about on the floor, EVEN A FRACTION OF AN INCH OR A FEW MM, then you may as well just use a carpenter's level. Concrete is NOT FLAT.

Then there is putting the level on the ways. Vee ways have a flat on top. And most people just put the level on that flat. But is that flat scraped in to be parallel to the other surfaces? And are there any dings on it? We are talking tenths here so even a very slight ding can throw things way off.

The last thing that I have learned is the "leveling" instructions for a lathe end with taking test cuts and further tweaking until they are as accurate as you want/need. So I ask myself, just how accurate does the leveling need to be before you proceed to this LAST STEP?

I have an import, master level. It is supposed to be in the same league as the Starretts and other high quality master machinist's levels. I have never had my lathe on a floor that allowed me to check on that claim. And I haven't used it in years: it is sitting on a shelf in it's nice case.

My point is, you can't just slap a level on the ways of a lathe and expect superb accuracy. You must look into the whole process. And stop when you reach a point where the lathe is good enough for the work you are doing. So yes, IMHO, EmGo has a point.

I guess it depends on your daily business. As a hobby machinist, I think I used my Startett 98 less than 5 times over 10 years. Every time was enough to drive me crazy with its sensitivity. However for machine rebuilders, it might be a different story. Anyhow the purpose of this thread was not the usefulness of master precision level, but more to wonder if it’s such a low tech that can be easily produced and sold for such a cheap by the Chinese, giving similar results to x40 and up more priced reputable brands

 

[memphisjed]

I guess it depends on your daily business. As a hobby machinist, I think I used my Startett 98 less than 5 times over 10 years. Every time was enough to drive me crazy with its sensitivity. However for machine rebuilders, it might be a different story. Anyhow the purpose of this thread was not the usefulness of master precision level, but more to wonder if it’s such a low tech that can be easily produced and sold for such a cheap by the Chinese, giving similar results to x40 and up more priced reputable brands

Yes, no. Can a just as sensitive level be made cheap- yes. Are the tick marks going to be any meaningful number, repeatable over three vials- doubt it. As said most times levels are used by visual center, within, and half bubble- numbers are not used.
Why are there no vertical presicion levels??! Finding flat to world is only half way on most machines.

 

[avivz]

Why are there no vertical presicion levels??! Finding flat to world is only half way on most machines.

Box / frame precision level?