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Dirty parts

Vladimir
Hello colleagues! Hope you have a great weekend and the sun is not burning around like in our region Sunglasses
In the light of recent events at our enterprise, it became interesting to me. Do you face the fact that poorly cleaned or completely contaminated parts are brought to you for measurements from production? Often, a small piece of metal adhering to a part can significantly affect the measurement results. In addition, part that is poorly cleaned from oil contaminates the probe, and microparticles adhere to it during measurement. One way or another, with a large number of measurements, I have no desire to check and clean every detail. We agreed with the production that they will do it, but last time we had to redo a large number of measurements due to poorly cleaned parts.
How does it work in your company?
  • Bwhahahahaha That's funny. Production cleaning parts. LOL. Even when they try, they have a hard time grasping how clean parts need to be for the CMM.

    Interestingly, we recently dedicated one of the CMMs for production to check every piece off the machine for a particularly problematic part. It was funny to watch them run the part and get undersize holes. I asked them if they cleaned the holes and they say, "I blew them out with air." I've seen them have to run the part 3 times before they got it clean enough to accurately measure the part. So finally there are a couple of operators that understand it, but if you haven't tried to check a part on a CMM when it's dirty, you don't really get it.

    Like you said, everywhere the probe touches is important, even if it isn't a tight tolerance, because the probe gets dirty and it affects other measurements.
    The struggle is real, my friend.
  • Well, I understand that no one can prepare a part for measurement better than myself. But my work is arranged in such a way that I do not have time for this, because while my CMM is doing beep beep, I am doing other work. And if I wipe every detail from oil and clean it of metal shavings, then I simply will not have time to complete all daily tasks, since my responsibilities include not only work on the CMM.
  • At my last job, if the part wasn't clean enough, we sent it back to the shop to be cleaned. My record was five times. The biggest problem I had was that the other CMM operators didn't care and ran the parts anyways which always caused headaches cause they were reporting back bad information to the shop. My new job is much better about cleaning parts. The most I have to do here is run gage pins through the holes.
  • My company makes critical safety stuff for aircraft engines, we take cleanliness ("FOD") very seriously. Once a year, we have mandatory company wide FOD training (watch a video on the computer). Individual departments have their own specific requirements that you're trained in if you work there.

    People from MFG who submit parts to the CMM are trained in FOD detection/prevention and understand that dirty parts = junk measurements. Along with that, the CMM operators can refuse a part submission to their area and send it back to MFG if its too dirty and the MFG floor is NOT allowed to argue.

    All of my CMM programs have this group. My CMMs haven't been called out for dirty/false part data in over two years (when I created the system)--> 
    GROUP_FOD =GROUP/SHOWALLPARAMS=YES
CLEANQUESTION =COMMENT/YESNO,NO,FULL SCREEN=YES,AUTO-CONTINUE=NO,
Is the part FOD free?

(Operator shall visually inspect part. Operator shall
clean part with alcohol, rag, airhose, pipecleaners,
AND/OR request upper level cleaning process if necessary).
IF/CLEANQUESTION.INPUT=="NO"
DIRTYQUESTION =COMMENT/YESNO,NO,FULL SCREEN=YES,AUTO-CONTINUE=NO,
Do you want to waste my time and measure this dirty part?
IF_GOTO/DIRTYQUESTION.INPUT=="NO",GOTO = CLEANQUESTION
END_IF/
IF/CLEANQUESTION.INPUT=="YES"
ASSIGN/CLEANSTATEMENT="Operator states that part was FOD free prior to CMM measurement."
END_IF/
ELSE/
ASSIGN/CLEANSTATEMENT="ALERT! Part was contaminated with FOD. The CMM's dimensional output may be incorrect."
END_ELSE/
COMMENT/REPT,
CLEANSTATEMENT
COMMENT/REPT,

ENDGROUP/ID=GROUP_FOD


    Because they know it will show up on the inspection report for the part...

    Nobody has ever selected NO the part was dirty.
    Every report has "Operator states that part was FOD free prior to CMM measurement." on it.
  • I work in an MRO with a dedicated cleaning department, so most of the time its no more than a quick wipe down in some spots. But they're typically staffed by the lowest paid, least skilled people in the building, and its not uncommon to have to change the route for the part and send it back to cleaning.
  • Yeah it is a huge problem everywhere I have ever been. Your guess is as good as mine when it comes to how to make them clean their parts. It may be a lost cause.
  • Yeah it is a huge problem everywhere I have ever been. Your guess is as good as mine when it comes to how to make them clean their parts. It may be a lost cause.

    all depends on training & the level of people you're working with.

    ive been on both sides of the spectrum.

    my current company is amazing with FOD prevention. training is great, people really care.
    my first company was terrible. i came home looking like a coal miner every day and if you tried to tell them what FOD was they'd tell you to f*ck off in polish so they could get back to drinking the acetone


  • all depends on training & the level of people you're working with.

    ive been on both sides of the spectrum.

    my current company is amazing with FOD prevention. training is great, people really care.
    my first company was terrible. i came home looking like a coal miner every day and if you tried to tell them what FOD was they'd tell you to f*ck off in polish so they could get back to drinking the acetone

    Yeah and I guess "huge" is relative. The first machine shop I ever worked in was coal miner dirty but the place I am now is definitely not that dirty. I just have to kick parts back a lot to be rinsed off and I clean a lot of holes with Q-tips but it definitely is not as bad as what you were saying. That sounds like a nightmare!
  • Bwhahahahaha That's funny. Production cleaning parts. LOL. Even when they try, they have a hard time grasping how clean parts need to be for the CMM.

    Interestingly, we recently dedicated one of the CMMs for production to check every piece off the machine for a particularly problematic part. It was funny to watch them run the part and get undersize holes. I asked them if they cleaned the holes and they say, "I blew them out with air." I've seen them have to run the part 3 times before they got it clean enough to accurately measure the part. So finally there are a couple of operators that understand it, but if you haven't tried to check a part on a CMM when it's dirty, you don't really get it.

    Like you said, everywhere the probe touches is important, even if it isn't a tight tolerance, because the probe gets dirty and it affects other measurements.
    The struggle is real, my friend.

    I've experienced this too on an even more awesome scale. I worked at a place that purchased two CMMs to be used on the shop floor to measure a family of parts coming off of a group on CNC machines that had parts that required 100% inspection. Both CMMs were outfitted the same so when a part came off a machine an operator could bring it to either CMM.

    It was pretty funny to see the operators learn about the need for cleanliness. At first, if a part measured out of spec, they would blame the CMM and measure the part again on the other CMM. Over time they caught on that the parts have to be really clean. And, the probes also need to be really clean. And, if you measure a dirty part with clean probes, the probes become dirty. Soon enough the CNC operators were all policing each other about only measuring parts that were absolutely clean so it wouldn't screw up the machine for their parts. It couldn't have played out better.
  • I have all my operators go through the holes with gage pins just in case. Management is complaining about parts taking too long on the cmm but i can't keep having the machines crashing. It sucks but until they learn to clean their parts properly we'll have to take this long
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