Total Incompetence - Quality is Calling My Parts Wrong… I Checked Everything TWICE… UNBELIEVABLE…
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- Опубліковано 25 гру 2021
- Machinist scraps his part, but is it the quality manager's fault??
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#CNC #Machining #Machinist - Наука та технологія
In my shop, we ran a rotation. A machinist would spend two days in inspection to learn what went on and an inspector would spend two days on the floor to understand what the machinist do. This was done every two months.
I moved from about 7 years in machining to QC as a CMM operator/Programmer for the last 3. Insure wish the floor guys would spend 15 minutes figuring out how to read prints.
@@brahtrumpwonbigly7309 My QC department would run a class once a month teaching just that. How to read a print. I did pay anyone who showed up overtime to attend. IT was a slow process but it worked.
QA/QC is a Mandatory 8 weeks before training on a CNC at our shop.
its the same on remote minesites.
one day a week the newbie will get to use the "relief" hole in the barrel during his time off, and one day a week the long-termers have to be in the barrel
@@twooldfartsinanrv7137 it's honestly a little crazy that this stuff isn't common knowledge with machinists, and that needs to change. Even button pushers need some basic knowledge of printreading and GD&T. It can only help, never hurt.
As my company's primary CMM programmer and operator with a machinist background, I manually check almost every failed dimension by hand unless it's too straightforward to worry about. While my title may be CMM operator/programmer, I'm in the quality department. I have no special allegiance to my CMM, I'm just trying to measure my parts right.
Always good to verify your results with other methods!
Ditto, If a feature fails I manually check it another way (surface plate inspection, air table, comparator, hard gage) to verify the result.
@@spivzit8754 exactly. Given that the CMM said that overall length was off, a quick check with a digital caliper would have probably been enough for a thinking person so say “wait a minute - something’s not quite right here.”
I remember this happening twice on tight tolerance bore dia on large dia components and it was the customers fault. (1) The component was delivered and inspected as they came though there door . Outside temperature - 5 deg centigrade .They reported they were undersize . Resolved when they checked them at standard temperatures (2) The component was delivered and placed in a large wooden crate on their diameter and left for 4 days before they were inspected .They were reported as being out of round . The weight of the rings on the dia caused the distortion . Resolved when placed on their side faces and left to normalise .Both these rejected components were caused by incompetence of customers knowledge of storing different shapes of components
and standard temperatures when they should be inspected.
I've run into the issue with quality and them thinking that CMM's are infallible gods. CMM's are no different than any other CNC machine. Garbage in, garbage out. It took a while for them to understand this
Hey. I know you! Did we even have a CMM at Omni?
Hahaha 🤣 exactly what I was thinking... trash in trash out !
I was a manual machinist for 20 years. Extremely light cnc experience. But
When the numbers don't check out in inspection first thing I would do is get some standards or go the granite room and check the tools I used. Yes I checked them before use but things happen.
Yes kiddies we had inspection even before CNC.
@@BerzerkaDurk Who is this? Whisper of Cognac is one of April's horses. Omni got a CMM about 6-7 years ago. I haven't worked at Omni for 3 years but, I still do contracting for them
@@douglaspierce7031 I'm your former brother-in-law. 😁 Whisper of Cognac was our horse. Peanut
@@BerzerkaDurk you still at Raytheon? I'm the engineer at a small shop in Amesbury
This part looks familiar. It is a part of a fuel system of a rocket engine. The one that delivers fuel for mixing. There is nothing wrong inn multiple checking especially in rocket industry. And yes, calibrated plates are always superior than a CMM.
Yes, it’s a Titanium Rocket Part…. We explain the entire process on our Free AerospaceAcademy.com
Isn't it against ITAR regulations to post images of liquid rocket injectors made in the USA? I know Space X has to censor footage and block certain parts when showing the rocket engines. Good video though!
@@n111254789 I am often surprised by what these guys decide to put on the internet.
@@sam_s_ Mind you I'm not 100% for sure, I'm in my early 20's and haven't done much with machining so I could be totally wrong.
Just a fan of rocketry, heavily invested in Rocket Lab currently and a part of a Cubesat program, and if I recall correctly there are laws on what is allowed to be shown and listed in regards to certain rocket components especially the manufacturing techniques for fuel injectors are the main thing. Similar issue with infrared optical sensors, and certain multispectral camera sensors.
Mind you I'm not mad at anyone for showing it. I just don't want someone to click on this video who's in the business and start hitting people with itar violations. It may be worth looking into because I doubt the video editor or the person machining it deals with itar ever and may not even know what they are doing could be illegal. I got in some issues with customs and itar over sending a consumer flir camera overseas, it was resolved with no consequences on my end but it is a pita and they take it seriously.
I would want someone much smarter than me to look into it. I just hate seeing people get into issues with the government over just trying to do their job and educate others. I imagine they know but I figured it would be better for me to say something and be wrong, than not say something and be right. They should for sure have someone verify if that's okay if they haven't already.
@@n111254789 I have work in buildings where they manufacture rocket and satellite components. We were not allowed to bring our phones with us and we were even told where we are allowed to look as we walk. If you turn your head, your escort kicks you out.
I was working for a small shop (4 people counting the owner) and we got a subbed job from another shop that we often worked with. They were volume production, we were a job shop, so when they got a package that included a one piece one off, they sent it our way.
It was a mixing/ color injection head of some sort, definitely off the wall, but doable. Had to have a CMM report. We didn't have a CMM. So we sent it out for inspection. Came back with some flunks. We recheck it. Looks right. Send it to a different shop to be ckecked. Get it back, but with a totally different set of errors. Sent it out again. Same thing!!!
Ended up going to the customer with all of this. They agreed to check it themselves. Passed with flying colors, and the final customer loved it.
The Ego is always going to make problems... Lose the ego start solving problems. Thanks for sharing!
Yup 100% agree. Everyone has different experience and knowledge. People get all butt hurt and suffer from "not invented here" syndrome. Meaning that if THEY didn't come up with the answer it can't possible be the correct answer. I hate that shit.
@@brandons9138 couldn’t agree with you more on that lol. Who cares, let’s just get the job done
Did a lot of work in machine & tool & die shops and an old timer told me close tolerances cause some in the trade to go mad. As an electrician would bust their stones saying if we are within 1/8" in metal or 1/2" in a masonary hole we were dead on. Have the upmost respect for you guys. Thanks for the great vids.
Fantastic post!
I worked in a QC department while going through college. We had a Mitutoyo CMM (manual) with Renishaw probes. My job was to do first article reviews and random sampling. I thought I knew prints forward and backwards until a Journeyman machinist explained MMC to me. We sat down (coffee and smoke break, as every 30+ year machinist smoked unfiltered camels then) and he drew a circle with a center point, then drew radial right triangles (x and y axis) to show how much MMC can be if hole size is near top end of tolerance (hypotenuse). I learned more from seasoned machinists in the QC department than I ever did in school……by far some of the smartest people I ever met! We worked together and learned from each other to make the best parts possible.
My dad was a 30+ machinist and smoked unfiltered camels. I remember him saying to always make sure you smoke it from the right end. No filter so I asked why and he said you don’t want to put a camels ass in your mouth. He would have loved his channel.
"if that thru hole doesn't line up with the bolt hole, what are YOU GONNA DO?"
I dunno boss, I guess I'd drill it out bigger until the oversize hole did fit the bolt on the other mating part.
"Exactly. That's MMC, kid."
Also, another way to think of tru-p is on an old school print with an X location and it's tol window and a Y location with it's tol window, you end up framing a square of all the possible places that is ok.
Spin that around it's center and it makes a circle instead. with diameter equal to the diagonal of the square.
Quality is not your enemy!!!! Work WITH them! Source:I’m a 13year machinist with 2 years of QA.
I'd just suggest that there should be a reference part that the CMM is checked on, one that is complex and really puts it through its paces, and use it to cross check the CMM on a weekly, or even daily, basis. That part should measure the same every time, and if it doesn't, then it's not the part that has changed.
Not when it takes 3+ hours to check one part...
The CMM should have more than ONE calibration Sphere and Alternate probes.
We did it daily when i worked for a huge amwrican multi.
Really cool. Glad you and your buddy are making these machining story videos. It’s like pent house forums for us CNC guys haha
Iv been a CMM Programmer for about a year now. It is so difficult to tell people when their parts are bad, and it's even hard when the machinist blows up in anger telling me that it's impossible that their part could ever be wrong. This has led me to triple and quadruple check parts before ever telling the operator/machinist that a feature or two are out of spec. Everyone trusts the CMM as long as the report is green, but when something comes out red it magically becomes the least trusted machine in the shop.
Ha no one trusts cmm reports. Especially on round features. I will never trust a cmm report on a runout, position of a large diameter with tight tolerance, or diameter of a diameter with a couple tenths tolerance. Always trust the indicator on a lathe before a cmm
@@cbrunnem6102 I'm with ya man, if I can avoid those features I will. If I can't then I make sure the engineer is really specific with what they need checked. The runout will always check different between it being chucked on the lathe and in a free(ish) state on the CMM. Usually for tight runouts I try to push for them to be checked on the lathe while it is set up.
As a QE, my first question of the CMM report would've been, is there a disparity between the 3D model and the drawing that the machinist is using to check it? Was the machinist and quality provided the most up to date drawing and model? In my experience, whenever there is such a massive disparity between what the machinist is seeing vs what quality is seeing, its usually because one of those parties does not have the correct information. Beyond that, I'd look at the CMM program itself, part setup, and first piece validation for each individual operation along the process. But I would've agreed, an entire CMM report showing failing dimensions and features is a huge red flag that a mistake was made when the inspector setup the part and picked up the datums.
In my honest opinion here, the biggest mistake was Quality sending off the report straight to management instead of getting together with the machinist in an attempt to understand why there was such a disparity and how to reach a solution.
Totally agree, as a machinist and later becoming a QE, I was always taught if you check anything and it is wrong the first thing you do is verify the error with two other devices when possible. In our shop quality and manufacturing work together to make the mfg plan and the qual plan ensure the best parts possible are produced.
Yea. Either a feature was off, in the model or at least had a bad hit when built off the CAD model, or it could even be that the datum on the part was messed up. Just throwing a failed report back at them is about the only unhelpful thing you could do in that situation.
@@JS-rh3sq That's exactly how I do it. Once I have a full understanding of the issue I go talk with the operator and possibly the programmer about it since I have machining experience as well.
As a QA lead and CMM programmer with a solid CAM background: the CMM program should have been written with iterative checks built in for it's first run through to troubleshoot that can be disabled or skipped over after a first run. This also irons out trouble with the number one most common CMM program flaw, bad alignments (root cause in this case) prior to committing time to the entire program. Third, QA should have understood the report they were outputting and (in)validated some of those features with other methods before then, fourth, taking it to production since helping the team MAKE an in tol part comes first in the value stream before documenting then archiving that it's good.
I do run into print/model discrepancies all the time. It's in our BPO how those are handled in an order of precedence/hierarchical arrangement. As well as in the QA procedure manuals (that I wrote most of to conform with prior company docs) for how to handle them when there is no-one around to ask for clarification.
If it was simply an improperly measured datum in the CMM then the measurements being out would look very similar to an improperly fixtured machine OP. I cant imagine any reason to report the results to the machinist prior to managment on a 1 off part. The machinist isnt going to make the decision to rerun.
We had this part where I was 100% sure that the part was good bc of how it was programmed. The Qualitymanager told me that those tolerances that were important arent correct. I checked the part on the plate too and double checked the programm and the fixture. In the end the long probe measuring most of the tolerances was being pulled down by the magnets holding the part on the measuringmachine.
That's crazy. Must've taken a while to figure that one out 😂
@@accumulator4825 never use magnetic clamping if possible
Thank you for sharing from your heart! I could hear your sincerity, words of truths, and humility. It takes a STRONG MAN to fight; it takes a REAL MAN to admit mistakes AND learn from them; it takes a WISE MAN to know when to hold his own tongue.
... or something like that.
Loved and deeply believe your words.
It's my dream to work at such workshop with such leader.
Accurate beautiful parts are killing.
I was,(still am), quality assurance in a foundry and cnc shop. Our procedures were always to check for calibration on every measuring tool before using it that day. Any wrong dimensions that were found, the measuring equipment was double checked and then the part re-measured. If it was still found to be wrong, we took it back to the machinist. We would then check the calibration of their measuring tools, and have them re-measure. It was usually a tool out of calibration.
Also, pretty sure the part he was showing was not the part that took 2 weeks.
I was wondering if you guys could do a video on different tools types, and their features. (Ex. End mill, shoulder mill, fly cutter, etc.) I’m an advanced manufacturing student at a community college and other than the exposure I get at work, I don’t have much. I’ve definitely learned a lot of applicable knowledge from this channel. Keep up the great content.
We had this problem where I worked, we made special ground tungsten electrodes . The customer said the electrodes didnt have right tungsten content , even those documentation from manufacture and independent lab said they were proper . We lost the job refused to do again thought same thing would happen in future
Great way on explaining a collaborative understanding!
A half a million high gauge or any other piece of testing equipment is only as good as the person operating it I worked a testing lab years ago. The lab manager gave me a piece of cloth from a dress to test for oil and grease. It was from a lady who took her car to an auto garage to be fixed. She slipped and fell in the auto garage and was suing the garage claiming she lipped because there was oil and or grease on their floor. I told our lab manager it piece of dress was too small to get an accurate results from but I would run it anyway. After I ran it I told my lab manager that there was absolutely no evidence of oil or grease on the piece of dress. He turned around, got on the phone and called the client her lawyers and said "There is evidence of oil and grease on the dress and you have a case". That was the exact opposite of what I told him. I later mentioned it to the the assistant lab manager and he said "I know what you mean and make sure you distance yourself from him and that case as far as possible. So as far as your client the engineers. They may be fancy engineers but that doesn't mean they have a clue what they are doing or talking about.
Excellent video. Grow together and you become an unstoppable team.
Well said, been in the same boat many many times. Some days I'm the dog, some days I'm the hydrant. But like you say, I've learned to go into these situations with a much more open mind. I just want to work out what is wrong, fix it and try to future proof it.
After seeing the fixture how the part is mounted to CMM table, wow... Anyhow as a CMM operator you should always question the possibility to your result and always double check to be sure.
In measuring, there is no absolute, only uncertainty, that is the mentality of a professional.
And yes, I'm a CMM technician. :) great video!
I'm grinding machine operator and to be blunt I'm quite fed up with one particular customer. The (wearing)parts that we grind for them are going to be in quite violent environment and if the tight tolerance is showing with their hightech measuring machine +0.001mm they scrap the part. Also they are finding concentricity 0.003mm off the tolerance in nearly EVERY part and always in the same place. I'd might get that if there wasn't any other diameters ground at the same setup, but there are several and those are all ok and the grinding pressure is basically nothing with my over careful program. Just not worth the effort especially when the price has to be next to nothing.. We do have also very good and nice customers too so not every day is horrible. Machinists knows.
Is there anything worse than a customer who thinks he knows more about his parts than the machinists who actually make it and understand its application and the conditions it will be subjected to? And he refuses to get his own inspection equipment checked for accuracy and consistency?
The only part I have a machine shop make for me has tolerances of +.001 and -005 inches and the surface finish requirement is "whatever a good cutter delivers is fine" so there's never a problem. I'm easy. It's HARD for any competent shop to mess up the part so badly it fails inspection. Oh, sure, I could spec every dimension to +/-.0001 inches and demand a 4 microinch diamond turned surface finish, but that'd be stupid and so far beyond real world requirements.
A job I worked on was sent out to three different shops that had CMM machines because the shop I worked for didn't have one but the customer required the report.
One of the reports came back stating that the part was 1.000" inch out of perpendicular. For those reading this you will have to take my word for it that if the part was that far out it wouldn't have fit on the fixture or been machine able for any other features. Not to mention you wouldn't need a CMM to visually see that much deviation.
I suggested our office not pay for that report. Whether they did or not I had no say.
1.000" out of spec? A measure off by that precision is itself highly suspicious. And if the claimed error is anywhere near that magnitude you don't even need precision measures to validate, just get out a ruler or tape measure.
I have had the same issue so many times i now look at any CMM report with scorn. A Certified Hard Gage is always the gold standard.
It's so true
It happens to allmost everyone's life in this trade
Great cpmment todd p. We are imperfect and prone to make mistakes.Everything comes down to people.Quality people with integrity will make all the difference.
Been there before.
I agree communication between the two departments is critical.
Sad but true; i've worked at shops where the inspectors had a machining background and where they did not. It always usually turns into a husband/wife style argument. Us as machinists aren't looking to produce bad parts; we just need the proper feedback and also most importantly competent inspectors.
makes good sense keep up the videos they are great .
I see this problem all the time. I am a CMM programmer/operator. The only time we really have a problem we have is hole location and it needs to be tweaked by tenths. We work with carbon composite thermoplastic so that add another level so the problems. But the biggest problem I have is when engineers do not what to believe that I do not know what I am talking about show them that the dies are made wrong.
The good old hassle with quality..
You gotta make sure to make them feel special and in control while telling them they're wrong is what i learned. Saves you a lot of nerves and saves them a lot of tissues ✌🏼
In school for machining right now... going to share this with my class. There's a couple of people there that could use this advice early on.
Excellent. I am willing to bet it made you a better machinist. I don't know how many times I had to throw it out and find a better tooling setup to get it right.
Great video. A confrontational attitude between inspectors and machinists is poisonous, and it’s management’s responsibility to make sure they are getting along. Same is true with regards to engineers and machinists.
Yes Yes and Yes… CAD CNC and quality must agree. In my company everyone is trained in all aspects,but specializes in one.
I've had this before. I had a cmm report saying something that should have been around 50mm was actually over 100 - clearly wrong, easy to demonstrate to the inspector that the cmm was setup wrong. No arguments
I agree completely. Have been programming CNC many years, worked in maintenance and now I'm quality engineer. My supervisor often tells me that this is a very valuable background 😸
The man who doesn't make mistakes is the man who doesn't get out of bed in the morning!
I worked at a place where an issue like this developed over months of time. Consumable machine tooling for a million dollar part were being made in house with only about a 50% success rate. Quality kept kicking out half the parts for poor welds. This went on for months, due to the urgency of the parts, machining was contracted out to a reputable machine shop, and the reliability of the parts didn't improve. So this caused MORE problems. The situation continued to devolve. Long story short, our department (maintenance) was brought in and we figured out the onboard digital angle indicator had a worn pivot point making the machine setup process inconsistent. Had the various departments worked together with less friction and distrust, this situation could have been avoided and a lot of money could have been saved.
A wise man once told me “check the checker”. It was regarding using a multimeter, the checker he referred to was both the multimeter and me.
Example; If you’re checking resistance touch the two probes together, do you get an expected result, if not maybe the multimeter is broken or maybe you set it to measure volts.
Yep, especially when the checker says that almost every measurement is wrong/off.
In the multimeters I've used, measuring resistance touching the probes together usually gets a few tenths of an ohm, very consistent for a given set of leads. An expected offset from a known source. Not usually relevant, values measured are much larger, but good to know.
Spot on. I'm a business owner for twenty years, engineering, cnc machine shop, quality. I've found these same things exactly.
CMM Programmer most likely created datums poorly or failed to qualify probe on calibration sphere or both. I programmed CMM for many years, was a skilled test engineer, CMM programmer (Hexagon, Mitutoyo & Zeiss), CMM trainer, calibration consultant/trainer and lab manager, and I only raised flags when something was wrong which could be proven wrong using height gage, pin gauges, gage blocks calipers or micrometer, etcetera. Not all CMM programmers fully understand how to properly program CMM in certain special cases, as I have encountered several CMM programmers (Automotive Industry) over the years not fully understanding GD&T and fully understanding how to properly program features to get correct/accurate results, and that is a problem. Fortunately I was able to provide detailed instruction with explanations why, so mistakes could be realized and understood by programmer. Glad you were able to get the issue resolved. I am retired now, and I still get calls with questions on calibration methods and programming.
I have just recently redesigned the layout of the quality lab that I work in. I am pretty happy with it, but I would like to know what types of measuring equipment you guys keep in your lab. My team and I inspect machined parts with complex features such as shafts and gears. I am interested in learning about new methods of measuring the common GD&T features such a as flatness, position, ect. That would help me put together and good training program/curriculum for new QC techs. Can you guys possibly make a video on which tools are best to use when measuring certain features and maybe a nice tour of your QC lab?
I love when quality starts arguing with hard measurements. Like you physically can not have an error there
Good video, been there myself tons of times
At my previous job I was a cmm technician/programer/operator for close to 12 years and to me its mindboggling with a cmm operator that measures a high end part where almoust every feature is out of spec without question his/her own work..
A good inspector with solid trig knowledge is rare.
One without it is a nightmare.
Gotta love it when your told that your threaded holes are too tight and it just turns out to be a burr or a nick on the thread gage.
Always sucks having to go to QC. They always jump into defensive mode. I remember getting into a big blowup with 2 inspectors over the difference between Maximum Material Condition on bosses versus holes. They were convinced that it was calculated the same way (they thought tolerance bonus increases as feature size increases for both holes and bosses). After looking it up, and making a few phone calls, the QC manager finally had to concede that the bonuses were opposite for holes and bosses.
When every dimension was wrong why didn't they think to use another method to double check the measurements (like you did) instead of relying on the one machine? That is pretty sloppy work and would have cost enough money to find out it was right after all.
Exactly. If so many things are out like described in the video, I always re-align the part and re-run the program. If it’s still out, THEN I manually check dimensions. I don’t understand how someone can think the cmm is such an infallible tool. We all make mistakes though and maybe the guy was having an off day.
@@RyGuy1135 Definitely having a bad hair day, every dimension being wrong would be a red flag.
I was a machinist first before working in quality. This was a big advantage when checking intricate machined parts. I did get operators trying it on, but once finding out that I could also machine the parts we got on fine. Also having prior machining knowledge could help solve problems that machines didn’t know about which was very much appreciated. Me I am retired now.
How much should a good machinist make in 2024? How long does it take to reach that level?
Bro, you're so brave!
Anything can go wrong if it can. If it can’t go wrong, you are wrong and it will go wrong. Amazing how such high tolerance parts can be produced.
This is a great lesson. QC doesn't like being the bad guy, you're a team, all what they're seeing and talk through stuff. Just as importantly sometimes QC needs to be told when something isn't going to get better so exceptions are made in a timely manner. I've worked as a tech, QA/ISO manager, and engineer. 90% of the time I grant exceptions because of my experience on the floor. If it's just the one issue I can probably live with it. Similarly, knowing something is hard saves me money.
Blows my mind that you guys have all this tech and still work in inches...
I have had to save parts from QC before, as I'm sure many of you have, with some of the parts I make there are dimensions on the print that serve no purpose , such as size of a chamfer which aids in installation, as long as there is a chamfer it's a working part, just not "in spec" . Our prints (for some parts) are guard rails to keep people on the highway, QC has the hidden numbers that are the true tolerances. You can't give your operators the absolute numbers, because if you give 'em .005" they will use all of it up to .0059" then be mad when it gets rejected.
Very true, most people forget that even the most expensive system may fail when operated by egomaniac... Having a second opinion or testing with different method will not hurt anybody...
Whenever I have a tolerance/measurement that just seems "off" I always have some one else take a look at it. It's a sanity check for me.
@@brandons9138 yes it is a humane thing, esp after gruelling hours of machining on several machines and that high pitch vibrating our spines, better take a breather than wasting time arguing...
Nice work I do recommend that you use gloves when measuring specially when touching the part or pins you would be surprised of how the heat from your fingers and oil left behind affects your test results
Machinist is a field I was interested in since I was a teen. I never got an opportunity to learn the trade. instead, I became a Field Radio Marine; and from there got involved in the repair and maintenance of computers. Now I am almost 62 and still have a desire to learn CNC. Is there a place for me in the CNC trade or is it too late in life for me?
Good advice all around.
As A retired Navy mechanic ya gotta get those specs right. Good job
You are 100% brilliant
Oh, I have been on both sides of the coin myself. Nice video
We would call that department wars. Much like shift wars
Even when I program a new part I will run it, if anything is out I take a quick measurement of what’s out and then run qualification on probes again and re-run. If it still comes out but the surface plate tells me otherwise then it’s my program that must have an error. Thankfully most of the time it isn’t my program that’s wrong, the part truly is out. However, my point is you need 3 methods that all say the same and then you can say it is OOT.
We have problems with cmm occionally. I machine ceramic prior to furnace hardening and infiltration. Titanium is a pain to cut. I really want to learn edm.
I was a cmm programmer for 10 years and never rejected a part without verifying it manually !
I'm not a machinist but worked in aerospace in final assembly.
Our quality control manager had a fit about the degrees of arc in a product.
Apparently it was incorrect.
He demonstrated its flaw to myself and a coworker.
While pointing to points of reference he said, "Ten, twenty, thirty, fifty, sixty, seventy, eighty, ninety. You see, the placement is incorrect."
I said, "Can you do that again?"
"Yes. Ten, twenty, thirty, fifty, sixty, seventy, eighty, ninety".
My coworker and I both looked at each other with stunned expressions.
"Could you do that one more time?
He did. Exactly the same.
He was a Quality control MANAGER.
This is how these people get to top level machinists.
Did they ever track down why the CMM went haywire?
It would behoove them to do so, because if the original cause is not uncovered it will happen again down the road.
I hope that's a demo part (I'm assuming it is) because ITAR might have some words if not.
Perfect post. QC and Production need to work together for sure. Just because you operate and program a million-dollar piece of equipment (CMM, CT or CNC) doesn't mean input is all good. Nothing worse than know-it-all QC guys that are incapable of making mistakes.
.0005 is not a very tight tolerance though I suppose when working on a CNC machine it might be, I frequently run parts manually to .0002 or better when I get a job that is .001 I sigh in relief because that's cake walk.
Unfortunately we dont have QC at our factory, we just go to the nearest tradesman after checking it and then he checks all the sizes
The problem is when there is something wrong they just say its wrong idk how to fix it because your on the oldest machine blah blah blah, it honestly hurts to go to someone, aswell as no qualified person is actually working with me on the machine, so im basically by myself, oh and then i gotta run 8 more manually loaded forging machines by myself...
Such a valuable video.
Iv had a part with a tolerance of + - .0005, with a cmm that was only accurate up to .0002. My part was .00002 out of tolerance( program went to deviation of 5 decimals even though the machine can’t measure that) Argue with the guy it’s a good part, put the part under my arm to warm it, and it’s a good part. Not ideal but all they care about is a good cmm report as you’ve said
Measurement uncertainty is always something to consider when inspecting a feature with a small budgeted tolerance. You can reject a good part...but also pass a bad one.
Just wondering if you guys ever use Wire EDM for close tolerances?
I have known more poor CMM operators than I have known good ones and a good one that truly understands gd&t is worth way more than they get paid while a poor operator that just pushes the button costs the company way more than there pay check!!!
We get this all the time with inspection with crap cmm programs and getting the alignment wrong.
God bless you man
Even the most expensive measuring device is just a paper weight without quality people. The struggle is real😂
Definitely pays to have a good working relationship with QC.
Sometimes, QC guys will cop an attitude saying "I've never made a bad part" , and try to screw with young people in the Machining trade.
You hit the nail on the head when you said we're all on the same team.
The guys from production, and QC need to work together to solve the problems. Real, or imaginary.
Another good video
QA inspector here - aerospace investment castings and aerospace machined castings/materials. A simple verification with hand tools or rock and height gage that contradicts cmm report is of great concern and indicates a cmm report not to be trusted.
All the top inspectors I have worked with will verify an out of tolerance dim. by measuring a different way and/or run their results by another inspector or leadman. A variation of the "measure twice, cut once" rule.
I weld pitching machine components and the hardest part of my job isn't welding, its making sure the stuff I'm making will actually work.
Taking responsibility is a tough one for all of us. No one enjoys being wrong and some bone heads will go to their grave while denying any wrongdoing.
I've SEEN people screwing up right in front of me and they adamantly deny doing it even though I just saw them doing it!
The sooner people get over their rabid denials of screwing up, the sooner some personal growth and team building can happen.
The moment we're in denial, all possibility of growth dies on the spot.
I pray that EVERYONE learns to take responsibility for their actions.
This is a common problem in shops all over the continent. Companies treat cmms like a god. 99.5% of the time they are correct. But every now and then there is some probe wear, calibration issues, or work holding issues. Just to name a few that have come up over the years.
Like you said both operators and inspectors need to work together and focus on solving the issues. More so than finding out who’s right and who’s wrong.
Perfectly said
Nice - I learnt something here.... Just wish I coulda got a job in machining :-/
this applies to software development. Great video
I find it bizzare that during training neither side is thought what the other is actually doing and how it's done, seems they should really get each others training as well.
I work in quality. Whenever I make a program for measuring a part, I ask the machinist how it went afterwards.
Quality is key, there is no other way
Before even watching this, I will make a guess:
QC has *completely* different specifications to look at than the Machinists. Both specifications came from an "Engineer's" original document, but were filtered through no fewer than 3 departments before arriving at your respective desks. You got a schematic for a hammer, and QC was expecting a wrench.
our problem is quality being closed minded and beyond question. instead of working the problem and forming a solution to eliminate the problem.
Welcome to the aviation industry. 👍
Welcome to the bridge between designer and the machinist, quality incompetence has given me sleepless nights as well, to an extent I had to measure and show them that the parts are ok.🤣🤣
There is a master's level course in teamwork hidden in this video.
If you think you're right. And I think I'm right. Then we aren't going to change each other's minds by shouting. Instead I'd always visit the other party and ask them to walk me through their viewpoint first.
Often that would allow me to spot the error they made. Sometimes it would allow me to spot the error I made. 100% of the time it would ingratiate me to them and make it much easier to come to a solution and a path forward.