Not only sunlight, even a bright led flashlight can make the bubble move half the length of the vial. At least that happens on my level with 0,05mm/meter which is approximately 6.5 tenth per foot...

Awesome information, thanks for sharing. Is Cont Machines still in business? If so, do they still make grinders the same way?

TD, years ago my wife and I took a stained glass class from a guy who soldered everyday for a living. Because of the exposure to lead fumes on a daily basis he decided to have the lead content in his body monitored annually. He had been monitored for decades and he told us his body lead content had never changed! It is amazing how much fear can be placed in a populous by various media outlets, even over a NATURALLY OCCURRING ELEMENT. I believe if you exercise some common sense and wash your hands, you may eventually die from something besides lead poisoning!!

Their time has value. So does your friends. Quality machine tools aren't cheap and you shouldn't take his for granted.

@@ShortArmOfGod Sorry if I explained that incorrectly. This fella is like my brother. We share projects all the time. I've helped him move almost all of his machines and he mine. Boy are there some stories there. No, he would be upset if I didn't ask him. Thanks again for sharing your experience and channel. Stay Safe

Sounds like you have a broken zipper. Lol :-) Personally, I don't worry about my barn door being open, the old horse has to get up before he can exit the barn. Lol :-) On a serious note: Most carpenter levels don't have adjustable vials, most vials are cast into place at the factory and require new casting compound to reset. It's worth the effort on good wooden levels with aluminum or brass corner rails. Most cheap plastic or all aluminum levels aren't worth it because the expansion and contraction will knock them out of level again too easily. Sorry about the cheezy humor, I couldn't resist! :-)

@@AerialPhotogGuy You could always just plane a bit of wood off to adjust the level ;)

Quick check. Just swap it end for end 180 degrees on a level surface. If the bubble moves the same distance each swap it’s accurate enough for carpentry.

@@ellieprice363 Same for high precision levels. As long as it reads the same both ways round, it's correctly adjusted.

You can not be convinced if you choose. So you know, many a machine tools are surface ground and then scraped. Grinding does not achieve the long distance flatness scraping can.

The nice thing about scraping is that you're constantly checking for the quality of overall flatness. With grinding you have to hope for the best, Keith often grinds his workpieces flat before scraping and then you see how flat it really is. Also you can scrape objects that don't fit into a grinding machine.

Parts ground on a surface grinder, no matter how shiny and flat they may appear, can only be as flat as the ways the machine table runs on. My 1988 Kent 6 x 18 table runs on two rows of precision .625 greased ball bearings in hardened and ground V ways. Although a recent inspection showed no detectable wear extreme part flatness would still require bluing and scraping to a certified straight edge.

@@grntitan1 So it's funny that surface grinders exist for that very purpose. It may well be done more for the surface 'finish'.

@@CatNolara It would be interesting to find out how unflat aground surface is. True about some surfaces being difficult to grind due to access difficulies.

A good idea is to check the calibration before use. The results of the check may or may not require calibration. You don't really know how accurate the calibration is from the manufacturer.

@@danburch9989 I have one of these, and the calibration from Starrett is spot on. But over time, with the normal knocks it can get in the shop, it can go off. It’s not really that delicate, but one sharp bang can do it. The difficulty is that Keith makes it seem easy to recalibrate, and it is, if you have a good surface plate and another calibrated master level. If you don’t, don’t play with it because you will definitely make it worse. Buying used ones is always a crapshoot.

You can check the calibration as you use it. You can get something level without the level being calibrated. Just make sure the bubble is off the same amount on each opposite side. it always level if you check both 180 degrees.

you can calibrate a level on any flat surface. It can be tilted and far from level it just needs to be flat. Rotate the level resting on the surface until it settles in the middle of the range. The bubble needs to be in the center. Place a heavy straight edge against the side of the level and a block against one end. This will allow you to rotate the level 180 and place it exactly in the same spot. Rotate the level 180, let it settle. If it reads the same it is calibrated. If it is off,, adjust it so the bubble travels half the offset towards the center. Once settled rotate the level until the bubble is centered. reset the straight edge and the end block. rotate the level 180...rinse and repeat until the level reads the same after rotation. No need for any other levels

Why do you think that? I thought it had just been used, not abused. I don't know much about this stuff, though. Honestly curious.

@@ianbutler1983 I may be wrong, but my understanding is Master precision levels are intended to be used under strict conditions both to ensure accurate results and to protect a fragile and expensive tool: Keith mentioned even the heat from your finger touching the glass can skew results. Generally you only use the "Master" tool when extreme accuracy is needed. (you would have lesser tools for rough work) With the base all scratched up you can't expect the accuracy that is required of the tool.

@@crichtonbruce4329 We kept our levels in their original wooden case. The levels are suspended in the box, only touching on the ends with dense soft padded foam. The level can be extracted from the box with a finger in the cavity on each end. The level then can be handled by the insulating top piece or gently gripped from the top reaching down the sides. My habit was to use clean hands and pass my palm over the level base before placing it on the machine surface. The machine surface was also cleaned. Using two levels set at 90 reference to each other allows machine leveling adjustment without introducing error by picking up and replacing the instrument to validate level in the other direction when you only have one tool. .0005"/ft error can be introduced by the smallest piece of dirt, so moving the instrument easily introduces error. I didn't like Keith's method of spinning the level on his surface plate when trying to calibrate the primary bubble. It sounded gritty on the video when he spun it. That indicated to me that debris was on his surface plate. I prefer to pick up the instrument, spin it in the air and gently place it to register marks on the surface. Keith "cheated" by trying to calibrate to his other tool. You can pretty easily adjust the level to itself, adjusting until it reads identically when turned 180 degrees. The surface doesn't need to be true level, but it has to be very close since there is only a very few divisions on the scale. I am retired and I don't own any of these instruments in my hobby shop. If I saw that level in that condition at a flea market, I would have cried for the abuse, but I wouldn't have bought it. We reserved our levels for machine leveling/calibration and only approved maintenance staff was allowed to use them. We had a Scherr Tumico of the same size and accuracy, but like all STI tools it just didn't have the same feel and finish as Starrett. It got very little use. Comparing STI to Starrett is similar to comparing Craftsman to Snap-On. If you can't afford the best, you settle for something less. This level was horribly abused. Our levels saw frequent use and showed no sign of abuse after 30 years of service. These instruments are so sensitive that the bubble takes many seconds to settle. The divisions on the bubble vial are .0005"/ft, but the division markings are clear enough to read to .00025"/ft. It is really tough to level a machine tool over its entire range within .0005"/ft. It isn't that it can't be done, but it is tough. Generally some portion of machine travel exceeds that limit. When that was the case in my experience, I would tune so my variance was outside the common machining range. A smug maintenance technician proudly walks away from his setup when that bubble doesn't move perceptibly over the entire range of a large machine tool. I have done it, but most often you can't expect to strut too proudly.

Send me an email. I show my email address at the start of each video when my name comes up.

Yes, I saw that too and cringed.

Doesn’t matter since the final degree of flatness is achieved by bluing and scraping.

The best way is to put a few drops of water or light oil between the paper and the surface plate, it makes the paper stick to the plate without affecting the flatness.

@@johncoops6897 ...Is "cringe" a word?

@@paulcopeland9035 - You can find out if 'cringe' is a word by looking in any dictionary. Linking is disabled here, so you'll need to do something for yourself.

imho, no. Box level, like hardware store extruded aluminum or the wood ones? Not even in the same league.

Prescision flat stones can be used to dress off the high spots. If there are only two bumps, restoration is pretty simple and you can have high confidence it is okay even if you can't measure it against a good standard.

Only if the temperature changes rapidly while measuring. If the temperature of the whole level changes equally, it doesn't matter. But if the level is sitting on a cold machine, while the room temperature is warmer, the level will warp slightly and your reading is off... That also happens when you hold it in your hand for longer than a few seconds...

@@Henning_S. on large mass items such as printing machines that take several days to install temperature changes makes a large difference.

Affect

@@paulhunt598 edited thank you,auto correct on mobile phone does not know😁

The surface being perfectly level doesn't matter and you don't need to use another level to calibrate a level. What matters is making sure the level goes in the same spot on the surface plate when turning it 180 ° and that the bubble goes to the same line on the level when turning it 180°. I hope this helps. God bless you! Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. John 3:3 KJV Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures: 1 Corinthians 15:1‭-‬4 KJV For all have sinned, and come short of the glory of God; Being justified freely by his grace through the redemption that is in Christ Jesus: Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God; To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus. Romans 3:23‭-‬26 KJV But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. Much more then, being now justified by his blood, we shall be saved from wrath through him. For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life. And not only so, but we also joy in God through our Lord Jesus Christ, by whom we have now received the atonement. Romans 5:8‭-‬11 KJV For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. Ephesians 2:8‭-‬9 KJV Therefore being justified by faith, we have peace with God through our Lord Jesus Christ: By whom also we have access by faith into this grace wherein we stand, and rejoice in hope of the glory of God. Romans 5:1‭-‬2 KJV That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. Romans 10:9‭-‬10 KJV

@@michaelboyle1983 Amen! Brother!

With some patients, you can figure it out without a reference level. When you flip the level and it reads on the same mark on both sides, it’s level and you can calibrate the bubble.

There;s some exaggeration here about fingers touching the level. I’ve experimented with mine over the years, generally after I see, or read about someone saying that. Yes, if you strongly grip the metal portion of the level with your hand, you can cause a slight heat transfer that will make a very slight error. But two fingers touching it to move it, won’t. The level just has too much mass for that to occur. It also depends on the temperature in your shop. I’ve found that summer temperatures give a slightly different reading that winter temperatures. Because the level isn’t the same in each direction in design, the bottom increases in size more than the top in warm weather, and contracts more in cold weather. So it’s ever so slightly convex in the hot summer, and ever so slightly concave in the cold winter. The readings can be different by about a line of reading, or 0.0005” per foot. Does it matter? Not generally. Squaring up a lathe bed will not be affected.

@@melgross I see I am throwing them too high again.

Buy a new keyboard. Your CapsLock key is broken.

@@johncoops6897, he’s yelling so you can hear him, I think it worked!

@@Hoaxer51 - but will Keith hear him?

I don't recall him ever talking about it, but I presume that he has his plates serviced regularly, and that he has more than one plate... I'm pretty sure that a well maintained plate is going to be *MUCH* flatter than his scraped level...

FFS pay attention. He's not introducing errors. He is on a almost DEAD flat surface plate, AND in a position that is almost perfectly level, AND has two reference plates to ensure that the position is maintained AND he is flipping the level end-to-end.

That level is about $1000 at Grainger. I have two Starrett levels. One is a 199. The other Starrett is longer and slightly different styling. I paid $400 for each of my Starrett levels. I bought my Starrett levels at an estate sale of a deceased machinis6. Do I need them? Absolutely not. Do I enjoy having them? Yes, very much.

The ask on the taper mic on ebay is insane. I suspect that they're hoping for someone with deep pockets and a high need.

@@isbcornbinder I bought a bunch of measuring tools from a retiring machinist and a Starrett 12" level was included. I was just tickled pink.

Ya, think? Yet the most accurate metrology equipment used by laboratories all over the world, and places like NIST are all running on had scraped ways. The two Moore CMMs in the NIST basement that every gage block is traced to have lovely moon pattern scraping all over them. There is nothing more accurate, even the 3 plate lapping method generates concave or convex surfaces depending on the sequence of laps. A 3 plate scraped method developed by Withworth is an order of magnitude flatter if done right

Do what - scrape or calibrate? And do you mean Bee or Vee groove?

@@johncoops6897 yes that right

@@johncoxhead8706 - yes what? You didn't answer either question LOL

Maybe because it may warp slightly if you mount it on the surface grinder. If you blue it up on the surface plate, it is just sitting there the same way as it does while using it. You don't introduce any stresses this way, as long as you don't hold it in your hand for too long, which causes warping due to the temperature difference...

Gauge blocks have lapped surfaces and wring or stick together. The scraped surfaces are equally flat but won't wring to another surface.

number two

What's a persission level ??? Do you mean scrapping or scraping?

No, these levels are not that delicate. Careful shipping should not affect the accuracy.

I see what you did there!

I'm an automotive mechanic and I feel the same way even with my best level

Maybe so, but they _are_ adequate for the task at hand. They are "fit for purpose".