Questions About CMM (Coordinate Measuring Machine) Gauge (Gage) R & R

Elsmar Forum Sponsor
J

jrubio

#12
Need to be done on each part (Significant Charasterist).

gard2372 said:
And if it's what they require, it should be included in their purchase order. Besides If I were a customer I would want a Gauge R&R on my parts done at least once. That way if there were assembly issues or other unforseen issues later in the process a re-inspection run on the CMM would be justified and compared to a master run/part.

I totally understand the set-up times and labor times a Gauge R&R puts on CMM programmers. But once the programs are written, it should be easy enough for production to schedule in the studies into their deadlines.

Remember, if it does take longer and the customer requires it, comply! Make them happy, but don't forget to add the additional costs into your quotes.

It is not neccesaty to be mentioned in the P.O due to probably your Customer call for a SPS, therefore you meassure a Cpk.

But the Cpk you meassure is not real is less than spected, imagine 1.7 and you calculate the ppm I think 2-3 ppm,

Well caution this calculation depends on GRR of the specific tooling meassuring the specific part.

Cp Act = Cp obs / Root Squate (1-(Cpobs*GRR)^2)

Refer to

FMEA, CP, SPC & MSA relationships and links (APQP Elements)

Therefore in my opinion this is mandatory minimum to make a GRR on the significant charasterist..

But if significant charasterist are shared by different products you sell to Customers, you can use whatever. but if the significant charactristic is different. Sorry.:bonk: :bonk:

Therefore if you not measured the significant characteristic for your Customer part you are not ensuring the ppms they want.
 
T

True Position

#13
Jim Wynne said:
How is it possible to "remove part specs"?
Sorry if I wasn't clear earlier, IIRC, and I may be mistaken. Previously, when calculating GR&R, once you had your variation, determined what percentage it was of your print tolerance and that was your GRR. Where the GRR was the percentage of your tolerance taken by measurement variation. Now it no longer directly is related to print tolerances, your GRR could be 50%, but only a small fraction of your print tolerance.

Here's the thought exercise I did:
Let's say I have +/- 25mm on a diameter.
For some reason I decide to send them for OD grind, and they hold them to .01mm.
I perform a GR&R with a plastic chinese vernier caliper, it fluxuates wildly over .10mm.
My GR&R is going to be something crazy even though the tool would almost never accept a bad part, nor reject an acceptable one.
 
J

jrubio

#14
GRR procedure

1) For each significant charasterist (Included in SPC).

Take the one with minimum Tolerance. :caution:

Apply GRR :whip:

All significant charasterist done?

yes Finish Goto 2
no. Go to 1


2) Do not put the PN in the R&R, refer beter to the name of the part, therefore you will not have reject of similar parts from your customer. :agree1:

3) If the Type of part is different Goto 1.

5) End.


:biglaugh: :biglaugh: :biglaugh:
 
D

Dave Dunn

#15
Randy Nemetz said:
The problem I have is that every customer will want a Gauge R & R on their specific part. I feel this is unnecessary if I have an acceptable R & R study performed on another part.
GR&R and other MSA studies are a means of demonstrating not just to your customer, but to yourself that the measurement systems you've chosen are appropriate and accurate enough for the measurements required. Measurement system analysis takes into account any possible sources of variation, including not just the equipment, but the operator, staging, and the measured part and dimension as well. Simply because you have a GR&R study on one part that reports as being good does not mean that another measurement with the same equipment will have the same repeatability.

Taking a simple micrometer check for example, there can be differences in variation depending on the rigidity of the part, surface finish, available contact area for the measurement, draft in the area measured, etc. These differences from part to part can have a big effect on measurement variation.

Now consider measurements on a CMM. Sure the probing location will be more repeatable, but you still have other factors such as part flexibility, stable staging of the part, type of measurement, number of points probed per feature, etc. If you're using a manual CMM and not a computer controlled one, you can also throw out the repeatability of probing locations.

This is not to say that you can't take a GR&R from one measurement and use it for others, you had best be certain that the measurement method is similar enough that it will make little difference.
 
Thread starter Similar threads Forum Replies Date
R ISO 17025 for our CMM LAB HAVE A FEW QUESTIONS! ISO 17025 related Discussions 2
D CMM Software ease of use and inspection of gears - Questions Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
C UDI Questions on Control Units Other US Medical Device Regulations 6
M NFPA 70 electrical harness questions Various Other Specifications, Standards, and related Requirements 2
L Project Managers - Questions For You Career and Occupation Discussions 0
B Toyota PPAP Process - Three Questions APQP and PPAP 3
A Internal Audit Questions ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 11
K Two FDA questions regarding UDI (and potentially 803.52 MDR) Other US Medical Device Regulations 0
D Signature Matrix questions ISO 13485:2016 - Medical Device Quality Management Systems 4
D ECO (Engineering Change Order) process questions ISO 13485:2016 - Medical Device Quality Management Systems 7
C 8.5.1.1 Control of Equipment, Tools, and Software Programs - Questions about the extent of control of NC programs AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 5
D Rules for Paper Forms outside of an eQMS - 3 Questions (ISO 13485) Document Control Systems, Procedures, Forms and Templates 9
D Shipping and recall questions ISO 13485:2016 - Medical Device Quality Management Systems 2
D Questions regarding process validation ISO 13485:2016 - Medical Device Quality Management Systems 6
M Quality Metrics Questions Lean in Manufacturing and Service Industries 2
K FDA Premarket Cybersecurity Guidance - 4 questions Other US Medical Device Regulations 5
A Some questions about voluntary consensus standards in traditional 510(k) submission US Food and Drug Administration (FDA) 6
T AMS2570E certification equipment questions AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 2
Mr Roo ISO 9001 - 7.1.3 Infrastructure - questions concerning evidence ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 26
K AS9100 - 7.3 - Are these black and white questions with specific correct answers AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 1
M Medical Device Identification & Codes - Article 27 Requirements questions EU Medical Device Regulations 1
Q Asset / Tooling Management - Two Questions Manufacturing and Related Processes 3
Q VDA 6.3 questions vs IATF 16949 clauses VDA Standards - Germany's Automotive Standards 0
I Questions to ask when auditing for Organizational Leadership and Planning for the QMS? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
A ISO13485:2016 name and ownership changes questions ISO 13485:2016 - Medical Device Quality Management Systems 3
C CQA Test Questions Bank General Auditing Discussions 1
E Three basic questions about ISO 9001:2015 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
M Informational EU – EMA revised guidance – Questions & Answers on Implementation of the Medical Devices and In Vitro Diagnostic Medical Devices Regulations ((EU) 201 Medical Device and FDA Regulations and Standards News 2
M Informational EU – MDCG 2019-6 v2 Questions and answers: Requirements relating to notified bodies Medical Device and FDA Regulations and Standards News 0
Ed Panek Relevant questions on Substantial Change Form CE Marking (Conformité Européene) / CB Scheme 3
K Beginner in ISO 45001 here! Three questions Occupational Health & Safety Management Standards 6
D Framing FDA Questions - Validation US Food and Drug Administration (FDA) 1
M Informational US FDA – Frequently Asked Questions (FAQs) About the Accreditation Scheme for Conformity Assessment (ASCA) Pilot Medical Device and FDA Regulations and Standards News 0
F Barcoding questions - Is there a plain English primer for newbies? ISO 13485:2016 - Medical Device Quality Management Systems 10
D Questions about the contents of a Design History File 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 3
S ISO 14971 Risk Management - Questions for Hazard identification ISO 14971 - Medical Device Risk Management 2
M Informational EU – MDCG 2019-6 Questions and answers: Requirements relating to notified bodies Medical Device and FDA Regulations and Standards News 0
C MDR Importer/Distributor Definition Questions EU Medical Device Regulations 14
A Purchasing - Internal Audit Questions Internal Auditing 8
M Informational USFDA – Efforts to evaluate materials in medical devices to address potential safety questions Medical Device and FDA Regulations and Standards News 0
M Informational USFDA draft guidance – A Risk-Based Approach to Monitoring of Clinical Investigations Questions and Answers Guidance for Industry Medical Device and FDA Regulations and Standards News 0
E Basic Risk based thinking questions Risk Management Principles and Generic Guidelines 5
F Job Travelers questions - unsigned operations AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 41
J Training documentation - ISO 13485 audit and the auditor had questions General Auditing Discussions 7
G Auditor watching tech do procedure - Can tech ask questions? ISO 17025 related Discussions 6
A Any recommendation for ASQ's CPGP (Pharmaceutical GMP Professional) Certification exam questions? ASQ - American Society for Quality 2
M Informational EU – Questions And Answers Related To The United Kingdom’s Withdrawal From The European Union With Regard To Industrial Products Medical Device and FDA Regulations and Standards News 0
F API Spec Q1 9th Edition Surveillance Audit - Questions about internal audits. Oil and Gas Industry Standards and Regulations 22
S SPC (Statistical Process Control) for Unilateral Tolerance - Questions Statistical Analysis Tools, Techniques and SPC 6
Ed Panek CE REP questions about our devices ROHS compliance REACH and RoHS Conversations 1

Similar threads

Top Bottom