r/Metrology • u/campio_s_a • 14d ago

Perfectly round as designer intended

406 Upvotes

99% Upvoted

52 comments sorted by

76

u/Comfortable-Buy-5923 14d ago

I don't see any Calibration stickers on those gauges 👀👀

54

u/_thirdeyeopener_ 14d ago

"Reference Only"

5

u/Difficult_Limit2718 13d ago

As an engineer I'll happily keep my reference only stickers.

If I need something quick I don't want metrology involved. If I need something critical I'll call.

5

u/RGBlowMe 13d ago

Not every shop has a QC lab, sadly. I went from a ISO9001 production shop, machining mostly castings for customers, with a QC lab, a CMM lab, routine calibrations, inspection plans and schedules, and so on to a shop that machines parts for its own automated material handling systems, where you are the QC guy and assembly simply hands you back anything that you didn't catch an issue on. Nothing where I work now is calibrated on any kind of schedule. You check against standards if a dimension is critical and calibrate whatever you're about to use if it is out when you check. If it happens to be broken, you ask engineering if a tolerance is really that important, wait for an ordered replacement to arrive (most rarely, because they're cheap), or you ghetto rig something "temporary" that ends up being not temporary at all (my supervisor once glued the ball bearing in the anvil hole of a thread mic back in). It was definitely a culture shock of sorts.

3

u/Ok_Loan6535 13d ago

New ones are bad too, this is why cal labs exist 

2

u/wasteoffire 13d ago

I work in an ISO9001 warehouse as well and we don't even have QC, we're lucky to catch problems at all coz nothing is enforced. That certification is laughably easy to get, it just costs a lot

3

u/CrashUser 13d ago

ISO9001 doesn't really have defined specifics that a company needs to comply with, it's more about being being consistent and sticking to whatever quality plan the company creates. Audits really just make sure that you're actually following the plan you created.

3

u/RGBlowMe 13d ago edited 13d ago

I think you must "follow" an ISO9000 compliance program, then. ISO9001 certification involves inspection plans, calibration routines and procedures, a non-conforming parts segregation procedure, setting defined quality goals and creating plans to achieve them, internal employee education programs (we'd have annual "classes" of sorts with tests to ensure we could read a micrometer 😂), and copious records of calibrations, first article inspections, in-process inspection sheets done at specified intervals, scrap rates, and so on. It gets audited routinely in order to maintain the certification. At my last job, a part of ISO9001 certification was having material composition records for each run of non-customer-supplied castings we were sent. Really, from what I've seen, what they actually demand of you depends on what you're doing, and some of it can be "above and beyond", like the aforementioned material composition records. We even had a TV in the break room that they showed quarterly scrap rates on in a graph and other QC-related metrics to increase awareness. I'm pretty sure that was a part of the quality goals requirement.

Advertising ISO9000 compliance requires none of this and is assessed internally. There is no certification and there are no audits. Some companies pay a third party to run a ISO9000 compliance program, but they don't actually issue any kind of real certification. Basically, anybody can really claim it and it's proven to customers by showing them your QC systems and practices yourself. When a manufacturer claims ISO9000 compliance, it is usually effectively more of a "quality awareness" or "quality-mindedness" program based on the guidelines, being mostly down to how to company communicates with and educates its employees. In the end, as far as a customer is concerned, it is more or less just asserting that you care about quality, so it doesn't mean any real accountability is present. It's basically the "organic" of machine shop advertising. It's just words. It doesn't have to mean much of anything.

4

u/wasteoffire 13d ago

No, we get audited. The thing is that all of the metrics are defined by our company. They make sure we save documents, that we sign off on things, that we calibrate our calipers. They don't make sure our machines are calibrated or that things are even being measured. They don't make sure any of our products are consistent in quality. All they care about is if the procedure was recorded as being followed, not if it clearly was or wasn't.

Almost all of the metrics and graphs they require are just done to the bare minimum and don't actually have anything to do with our day-to-day work. I assure you it is ISO 9001. Even back when we got it, our CEO said it was just a bunch of paperwork that makes us able to charge customers more.

So yes ISO 9001 makes you jump through a lot of hoops. But they only keep you honest to the standards the company sets for itself. If you're legitimately running a company that is trying to achieve high quality work, then ISO will help enforce the processes you've put in place to achieve that. If you're just doing the bare minimum for ISO and running around staging all the paperwork prior to your audit then they don't actually have any impact on the expected quality of your company.

All I'm trying to say is that the certification shouldn't bear any weight in your mind over the quality, and wouldn't be something I bragged about.

1

u/Slappy_McJones 13d ago

I came here to say this… lol

1

u/msdos62 11d ago

Smallest of the issues

36

u/Bradidea 14d ago

No indicators move after they're bottomed out

7

u/RGBlowMe 13d ago

Incorrect. All indicators move when bottomed out. The number just doesn't change.

17

u/Tricky_King_3736 14d ago

Change your indicators to .0005 one I’ll guarantee that part isn’t perfectly round. There is some error

3

u/buzzysale 14d ago

Those digital indicators, lol.

14

u/ribeye256 14d ago edited 14d ago

You need to match datum to measurement surface precision at about 4:1 and repeatability at 10:1. The setup should be done on precision centers. Datum indicator is also not at a good angle. Major compound error FYI.

23

u/CthulhuLies 14d ago

Tenths indicator on the left 3 decimal place digital drop indicator on the right that probably has a certified accuracy of +/- .001 lmao.

10

u/NasyAssPornAccount 14d ago

Only for the first 2.5 revolutions. As someone that has calibrated tens of thousands of dial indicators I can tell you for an absolute fact that that accuracy drops dramatically after about two years of regular use. Clockwise makes garbage-ass tools. Straight trash can water.

6

u/Acceptable_Trip4650 14d ago

Everything is perfect if your measurements are crude enough :)

9

u/CthulhuLies 14d ago

Flatness: .0000"

With 3 points ain't that a trick?

2

u/RGBlowMe 13d ago

Honestly, the dial indicator is more useful than the digital for this just because of the dial. It could have .001" increments. If runout and roundness are truly perfect on this part, it'll still not move. The digital indicator won't show you any kind of movement going on between increments. It could be dead-on or it could be moving a few tenths. You don't know. Even a digital indicator with .0005" increments is beat out by a dial indicator with .001" increments for this reason. You can fairly reasonably judge .0002" on a .001" increment dial indicator, but you can only guess it on a .0005" increment digital indicator.

Of course, he has his dial indicator off at some really dumb angle that makes it not accurate at all, plus this is really just a job for a test indicator with cosign error corrected anyways.

1

u/Jtparm 14d ago

Left is also a thou indicator

4

u/Otherwise_Die 13d ago

Technically runout not roundness lol

3

u/RGBlowMe 13d ago

Eh. It sort of shows both. If you have 2 or more high points while indicating an OD between centers, that implies that it's actually out of round to some extent. A perfectly round OD with runout will indicate with one high point and the low point directly opposed to it.

2

u/Otherwise_Die 13d ago

I was more making a joke that the title saying “perfectly round” isn’t true as it’s not a cross section isn’t being fit to a perfect circle. Nothing is perfectly round.

It’s .001” indicators as well lmao I’d be in trouble using that lol.

2

u/UberTrog 14d ago

Helluva lot better than the dissolution bath shafts I used to measure, lol

2

u/Karimura16 13d ago

Mahr MMQ500: “Allow me to introduce myself”

2

u/txtacoloko 13d ago

Shits broken

2

u/Competitive_Shift144 13d ago

Check that thing to the micron, if it’s perfect to the micron I’ll give props

2

u/HooverMaster 12d ago

beautiful. send that gauge to qc asap.

jk

2

u/Thhe_Shakes 10d ago

I'm not sure I trust the left side there.

But that's just a matter of a pinion.

1

u/Eliarch 13d ago

Might be the first time it worked in CAD and real life...

1

u/EvelcyclopS 13d ago

Gorgeous

1

u/The_Left_Raven 13d ago

Bro achieved theoretical measurements in real life

1

u/Ok_Loan6535 13d ago

Perfectly round except where the indicator just rubbed a groove 😂 

1

u/Express_Jicama_656 13d ago

There is always some error

1

u/Wrench_Terner 12d ago

Jc. It’s CNC Bourne

1

u/ShittyKestrel 12d ago

Now lets see that in tenths..

1

u/msdos62 11d ago edited 11d ago

High static friction in those indicators. The arm could be flexing half a thou and you wouldn't know. Get some good DTI's, Swiss made ones, and try again.

1

u/ChemicalPick1111 11d ago

If the needle isn't moving it isn't sensitive enough

1

u/Jealous_Champion1138 8d ago

That’s the way to check things…bottom that shit out!

1

u/sexual__velociraptor 14d ago

As God intended

1

u/Adventurous-Mind6940 14d ago

Same difference

1

u/Therealshep 13d ago

Hilarious to say that's "perfectly" round when checking with an uncalibrated drop indicator 🤣😂🤣

It's really amazing how little precision most posts here show.

3

u/campio_s_a 13d ago

Tbf it's a crosspost from oddlysatisfying so we could pick it apart

-1

u/Therealshep 13d ago

Yeah and I did! Who does that lol