Inspection and Quality control of components produced on computer-controlled machines

HI everyone

I am an engineering student and have received an "Inspection and Quality Control in CAM Systems" assignment. So am writing in the hope someone may be able to help me in answering some of the questions that I am having a little difficulty with.

I have researched and answered some of the required questions, but hope someone may be able to help me with the scenario and the remaining questions:

As a production technician, you are asked to examine methods of inspection and the quality control of components produced on computer-controlled machines. You are to report your findings to your manager and should cover the following aspects:-

1) Levels of inspection. e.g. tooling verification, datum and location checks, in-process measurement, post process inspection, qualitative data and attributes, statistical analysis, technical and management information.

2) Data capture e.g. tactile sensing, non-tactile sensing and data transmission features.

3) An explanation of the significance of adaptive control methods employed within CAM systems.


Any help or advice that you can offer with any of the questions, will be very much appreciated and will help me no end with my studies.

Thanks in advance :bat:

I'd answer but I don't wanna get my blood sucked out by no vampire thingy! :D

Tell us what you've got so far, Carla. Maybe someone will offer to throw in a comment.

He, he, you liked my vampire/bat then. Do not worry, I have the vampire/bat well under control.

For questions 1) Level of inspection, I have a little bit of information on "The close integration of Software with probe systems provides a robust solution for the wide range of applications for On-Machine Verification”

Should I be using this probing and software system as the basis for the whole of question one? I.e. tooling verification, datum and location checks, in-process measurement, post process inspection, qualitative data and attributes, statistical analysis, technical and management information, as a whole or are these functions performed by different systems, methods, or software? Is this probing and software system something that is available through an existing CAD/CAM system, or is it something that needs to be purchased separately? Also, should I be making any type of mention on CMM?

For questions 2) Data capture, I have a little bit of information on. “Tactile sensors can be used to sense a diverse range of stimulus ranging from detecting the presence or absence of a grasped object to a complete tactile image and consists of an array of touch sensitive sites, the sites may be capable of measuring more than one property”. “The development of robotic systems capable of operating in unstructured environments or aimed at replacing human operators in hazardous or inaccessible locations relies on the use sophisticated sensors capable of fine from discrimination and the detection of inicipient object slippage for precise and secure object grasping”

I have no information on “non-tactile sensing”, “data transmission features” or “adaptive control methods employed within CAM systems”

He, he, I have made my own head spin now.

Carla

I get Q#1, on machine probing, I think. but is Q#2 about using electronic sensors to measure and capture/record data or is it for determining the presence/absence of a work piece? As for Q#3...?

I have no idea, that is why i placed the question on the forum. That is, in the hope that someone might be able to help me.

Try google searching of "tactile sensing", "non-tactile sensing”, “data transmission features” or ”.“adaptive control methods employed within CAM systems" I think at least good defenitions can be found there. I tried "tactile sensing", “adaptive control methods employed within CAM systems" and got some hits.


A.J.L.

I have been studying for five years now and always search the Internet.

I have already carried out searches on the required questions, and received thousands of hits. Unfortunately, most of the sites only make reference to inspection and the keywords used and do not actually explain or touch on the information that is relevant to the questions, either that or i do not recognise the significance of the information.


Perhaps you can share the information you found on "tactile sensing" and “adaptive control" methods employed within CAM systems" and we can see if this is relevant specifically to the questions.

Carla

on way to verify part on machine is with a point program using a indicater from a fixed location to verifty tool path before removing. We did this at Rolls Royce for propellers to compare countor of part to programed points

Thank you for your help guys

So far i have managed to answer: Tooling verification, datum and location checks, in-process measurement, post-process inspection, tactile sensing and non-tactile sensing.


But could still do with some help on the following:


Q1) Levels of inspection: Qualitative data and attributes, statistical analysis, technical and management information.

Q2) Data capture: Transmission features.

Q3) An explanation of the significance of adaptive control methods employed within CAM systems.

Thanks in advance

Carla

Having worked for a major OEM automaker with GREAT quality ratings, I found their method of QC to be extraordinarily simple - many GO-NOGO gages.

Having worked for a rolling element bearing maker, they too had many in process checks (IE: 100% clearance measurements, 100% noise tests, etc all done with sophisticated electronics using proprietary algorithms). Size control checks were done with air gages, all calibrated against the same standard regularly - process control was deadly accurate, again with simple gages religiously checked/maintained.

We make prototype camshafts. Our lobes are all 100% computer inspected for profile and finish prior to being shipped. The shape of the acceleration profile (2nd derivative of lift curve) tells us if and where an error may exist. WHen you make parts on a onesy twoesy basis, PPM's are irrelevant. 1 part in a million is probably 100% of our production.

The inspection process you'r being asked to quantify/describe is going to be hard to get your arms around. I'd first create a hypothetical widget. Once you know what the critical features are, you can then set up an inspection method and the equipment thereof. A that point, the project can be defined as can the level of inspection, and all the other stuff you're being asked to provide.

For example, in camshafts, you can have a overall lift variation allowance of 0.003". Yet, on a degree by deg lift variation, you have to hold deviation under 0.0001"/deg. Yet length issues can vary by 0.005 in some areas and 0.030 in others - all tolearance of the SAME feature, a lobe.

BIG difference in the inspection method and equipment and time needed to do the certification.

Whether or not you can do adaptive controls of the process is a function of the type of equipment being used to make something and how much freedom the operator has to "tune it". Contrary to what your prof says, there are still industries operating with analog control systems that involve hard tooling and trained operators - not everything is CNC'd nor "tuneable".

EDIT: one more important issue: you can NOT inspect quality into a part. You have to develop an attitude that you will BUILD quality into it from the get go.

Demand perfection and provide your staff with the tools to provide it and you find that your staff will strive to deliver it and take pride in doing so. You will make money by NOT making scrap....

When you lower your expectations (and your level of quality), your staff will not fail to disappoint you....