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What Do I Inspect? - RANT

Hello Everyone,

For the most part, I've had unbelievable freedom when it came to creating a CMM inspection program. Number of points, which dimensions to inspect, which to leave out, what to name the features, number of probes needed, types to styli, etc... Managers and operators only asked my to to specific things that would help them with their jobs.

Example 1 is that I might get asked to check certain features first so they get quicker feedback for CNC offsets. That may be a slightly longer program or I might have to load a probe more than once but that's how they wanted it. Ok, I can do that.

Example 2 I'm checking a feature with a loose tolerance that is always out of tolerance but it doesn't affect the fit, form, or function of the part. Operators have to enter in non conformance reports which hold up the part from getting further processed and engineering has to get involved in the decision to accept or scrap to that part sits and waits which is a waste.

Example 3 is let say there is a reference dimension that the operators do by hand that is not on the drawing. No problem.

Example 4 is when non conformance reports on consistently entered to engineering and they finally tell me not to check that feature anymore because either its not important or production just can't hold it and therefore not important enough to check.

Example 5 is when the CMM inspection is longer than the CNC run time so now managers get involved, we have a meeting and review what is being checked and they ask me to remove what ever measurement that aren't needed to save time.

So about a year ago, our engineering department started using numbered bubbles on our drawings. We had a meeting and they said to only check what was bubbled and also to name the feature after the number inside the bubble for clarity and standardization. Great. That was so helpful to me. CMM programs and program creation got much faster.

Then we had a meeting a few months ago about only checking the numbered bubbles was NOT their intent. We need to check all the features at some point not just the numbered bubbles. Since there was some confusion, engineering decided to no longer use the numbered bubbles anymore ( I think they are just trying to save time on their part) so I'm back to square 1. Whiskey Tango Foxtrot.

So now that I've been programing for a few years, I understand that I don't want the CMM to be the bottleneck and give the operator as much dimensional information as they need to get their job done. Now I'm approving drawings and the new versions have no numbered bubbles and tolerances are changing and I'm at the point to where I'm asking myself, what do I inspect?

How do you all get your instructions for creating inspection programs? Does every inspection program need to be a meeting?
Parents
  • We are a production facility and most of my CMMs are in cells that run just one part over and over. Once I set them up, I usually don't need to touch those CMMs unless there are issues related mostly to hardware like probe got loose or fixture is wearing out. Some of my CMMs do run a small mix of parts. As a manufacturing plant, we are trying to stay flexible when it comes to our CNCs. We are constantly offloading parts from 1 CNC to another to accommodate new products coming through which means I need to move CMM programs around which can be a pain sometimes.

    Another issue my CMMs don't have the same heads so moving programs around can take some time.

    I'm on the fence about a meeting for every part. I do think that would be beneficial so every department will be on the same page but I think it can be a waste of peoples time as well. Have my own bubble drawings would be great but it would go against our policy to keep duplicate drawings and I wouldn't keep up with revision control.

    There are only like 2 guys here that are the brains of the entire operation. I think I'll have a chat with them about what to inspect. I'll initiate the meeting by getting the current drawing and inspected everything that particular CMM can inspect. Tell them this is what I plan on checking on this part, speak now to remove inspections or this will proceed as is.
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  • We are a production facility and most of my CMMs are in cells that run just one part over and over. Once I set them up, I usually don't need to touch those CMMs unless there are issues related mostly to hardware like probe got loose or fixture is wearing out. Some of my CMMs do run a small mix of parts. As a manufacturing plant, we are trying to stay flexible when it comes to our CNCs. We are constantly offloading parts from 1 CNC to another to accommodate new products coming through which means I need to move CMM programs around which can be a pain sometimes.

    Another issue my CMMs don't have the same heads so moving programs around can take some time.

    I'm on the fence about a meeting for every part. I do think that would be beneficial so every department will be on the same page but I think it can be a waste of peoples time as well. Have my own bubble drawings would be great but it would go against our policy to keep duplicate drawings and I wouldn't keep up with revision control.

    There are only like 2 guys here that are the brains of the entire operation. I think I'll have a chat with them about what to inspect. I'll initiate the meeting by getting the current drawing and inspected everything that particular CMM can inspect. Tell them this is what I plan on checking on this part, speak now to remove inspections or this will proceed as is.
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