SPC and Process Capability Using a Romer Arm

N

Neverclue

#1
My question pertains to some research I have been doing into the new Romer Absolute Arm 7525 Model. It lists a point repeatability of .0008 and a volumetric accuracy of .0011. Is there a generally acceptable accuracy range for calculating SPC and Process Capability? My tolerances range all over the place from .005 to .030 depending on the industry we are molding for. The arm comes with some very nice software for SPC, PC, PPAP, etc...but I am concerned about the viability of the data when it comes to actually using it to prove process control and repeatability to customers. Does anyone have experience with this type of situation, because mine is limited.

Thanks!
 
Elsmar Forum Sponsor

Steve Prevette

Deming Disciple
Staff member
Super Moderator
#3
My question pertains to some research I have been doing into the new Romer Absolute Arm 7525 Model. It lists a point repeatability of .0008 and a volumetric accuracy of .0011. Is there a generally acceptable accuracy range for calculating SPC and Process Capability? My tolerances range all over the place from .005 to .030 depending on the industry we are molding for. Thanks!
Keep in mind that if you desire to use SPC - you are analyzing the actual results from the machine.

If you do go into process capability, then you would be looking at the SPC versus the tolerances.

The SPC anlaysis may let you know if the manufacturer's promises are being kept or not.
 

Bev D

Heretical Statistician
Staff member
Super Moderator
#4
The general rule of thumb concerns the resolution of the gage. the resolution should be at least 1/10 of the tolerance spread for acceptance testing and 1/10 of the actual variation spread for SPC.

The manufacturers stated "accuracy" is not that. Nor is it a statement about the measurement error. It is a theroetically perfect value if NOTHING else varies; in real life everything varies.
 
N

Neverclue

#6
Thank you for the response!

So, to clarify for my case, is the resolution the point repeatability spec that reads as .0008" on the spec sheet? How to I determine if that is enough resolution to create an SPC chart/Gage R&R/Cpk etc. that isn't worthless? That's what I'm having trouble figuring out.
 

Bev D

Heretical Statistician
Staff member
Super Moderator
#7
Neverclue - you MUST do a real MSA to determine if your Romer is suitable for your needs. The vendor's specs tell you almost nothing.

There are some features that our Romer Arm is fine for - others not so much.
 
Thread starter Similar threads Forum Replies Date
J Is it the same process capability or performance in 8.2.3.1 and SPC? IATF 16949 - Automotive Quality Systems Standard 1
V Defining Subgroups and Importance of Subgroups in SPC and Process Capability Statistical Analysis Tools, Techniques and SPC 6
M Capability level applicable to SPC process or overall process? Statistical Analysis Tools, Techniques and SPC 16
I Reason for pre-production machine/process capability studies / SPC during production Capability, Accuracy and Stability - Processes, Machines, etc. 3
sathis AIAG's SPC manual 2nd edition - Page 189 - Process Capability Formula error? Statistical Analysis Tools, Techniques and SPC 1
Marc Steve Prevette's Statistical Process Control (SPC) "Library" Statistical Analysis Tools, Techniques and SPC 0
S SPC (Statistical Process Control) for Unilateral Tolerance - Questions Statistical Analysis Tools, Techniques and SPC 6
A Electric terminal crimping machines - Is SPC appropriate for this process? Manufacturing and Related Processes 4
P SPC Short Run Advice of a Stamping Process Statistical Analysis Tools, Techniques and SPC 3
A SPC for Single Batch Nickel Plating Process Capability, Accuracy and Stability - Processes, Machines, etc. 5
E SPC Corrective Actions - Best Practice with Process Statistical Analysis Tools, Techniques and SPC 2
O Is SPC (Statistical Process Control) always required? Statistical Analysis Tools, Techniques and SPC 4
M SPC (Statistical Process Control) Book Recommendations wanted Book, Video, Blog and Web Site Reviews and Recommendations 1
I How to use Statistical Process Control (SPC)? Statistical Analysis Tools, Techniques and SPC 8
B SPC on Weight of Plastic Injection Molded Parts - What variables affect my process Statistical Analysis Tools, Techniques and SPC 2
C SPC for a Changing Process such as Tool Adjustments Design and Development of Products and Processes 23
J Definition Control - Definition of Control in SPC (Statistical Process Control) Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 8
K How to start Implement SPC for Injection Molding Process? Statistical Analysis Tools, Techniques and SPC 24
T Recommend books on SPC (Statistical Process Control) Statistical Analysis Tools, Techniques and SPC 3
P Hard Milling Process - Dealing with Within Part Variation for SPC Statistical Analysis Tools, Techniques and SPC 18
B SPC for Automotive Paint Manufacturing Packing Process Statistical Analysis Tools, Techniques and SPC 2
S SPC (Statistical Process Control) books - Suggestions and reviews please Book, Video, Blog and Web Site Reviews and Recommendations 3
O SPC Statistical Process Control with All data Using Minitab Software 4
J What SPC (Statistical Process Control) software is your company using? Statistical Analysis Tools, Techniques and SPC 15
T Touch Screen Capable Software suggestions for SPC (Statistical Process Control) Quality Assurance and Compliance Software Tools and Solutions 4
H Getting A Supplier to use SPC (Statistical Process Control) Supplier Quality Assurance and other Supplier Issues 5
P ISO 9001 requirement for SPC (Statistical Process Control) ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
Batguy SPC (Statistical Process Control) on Go/No-Go Checks Statistical Analysis Tools, Techniques and SPC 18
M SPC (Statistical Process Control) analysis and status on two manufacturing plants Statistical Analysis Tools, Techniques and SPC 4
V Statistical Process Control (SPC) for Clean Room Environments ISO 13485:2016 - Medical Device Quality Management Systems 6
V SPC (Statistical Process Control) for Medical Device Company Statistical Analysis Tools, Techniques and SPC 4
C Is Parts/Process Average Testing SPC by Another Name? Statistical Analysis Tools, Techniques and SPC 3
C Centerless Grinding (SPC) - My process is extremely out of control Statistical Analysis Tools, Techniques and SPC 16
J Learning Statistical Process Control - I need a crash course in SPC Statistical Analysis Tools, Techniques and SPC 8
C Starting a Small Lot SPC (Statistical Process Control) program Statistical Analysis Tools, Techniques and SPC 8
I SPC (Statistical Process Control) and SQC (Statistical Quality Control) - Difference? Statistical Analysis Tools, Techniques and SPC 1
R SPC (Statistical Process Control) for Unilateral Tolerance Statistical Analysis Tools, Techniques and SPC 10
S SPC (Statistical Process Control) - I have data, now what? Statistical Analysis Tools, Techniques and SPC 14
S Reaction Plan for SPC (Statistical Process Control) Chart Statistical Analysis Tools, Techniques and SPC 4
J New at aluminium die casting process (injection, trimming, spc, finish, defects) Manufacturing and Related Processes 3
M Is SPC (Statistical Process Control) useful? Statistical Analysis Tools, Techniques and SPC 72
C SPC (Statistical Process Control) software recommendations Quality Assurance and Compliance Software Tools and Solutions 23
J User Friendly SPC (statistical process control) Software Quality Assurance and Compliance Software Tools and Solutions 14
Tim Folkerts Is it Time for New Rules for SPC (Statistical Process Control)? Statistical Analysis Tools, Techniques and SPC 22
C SPC (Statistical Process Control) for Management Reports Statistical Analysis Tools, Techniques and SPC 2
sathis Difference between SPC (process control) and SQC (quality control) Statistical Analysis Tools, Techniques and SPC 12
Marc Definition Statistical Process Control (aka SPC) - Definition Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 0
Q AIAG Releases the 2nd Edition of their SPC (Statistical Process Control) Manual Statistical Analysis Tools, Techniques and SPC 19
J ISO 9001:2000 - SPC (Statistical Process Control) requirements Statistical Analysis Tools, Techniques and SPC 4
Steve Prevette SPC (Statistical Process Control) Overview Statistical Analysis Tools, Techniques and SPC 101
Similar threads


















































Top Bottom