precision machining

  1. Marc

    Free Bob Doering's Blog Post Series 1.0

    Bob Doering's Blog Post Series mainly related to SPC in Precision Machining. Included Blog Entry Categories: SPC GENERAL GENERAL STATISTICS METROLOGY GENERAL QUALITY CONCEPTS A Trusted Resource! Please click the orangeish "Download" button.
  2. bobdoering

    SPC Charting frequency calculator for X hi/lo chart

    One of the things that is unclear with Shewart charts is the frequency of charting. However, with the X hi/lo chart for precision machining, the frequency can actually be calculated. Attached is the Excel calculator for determining frequency. The tool wear rate is based on the linear...
  3. M

    Process Capability in a High Precision Environment

    Hi Everyone, I just started introducing the automotive process control approach in a non-automotive, high precision manufacturing business. Immediately it's clear that many of the grinding tolerances (0.003mm) are very difficult to achieve and even harder to measure due to resolution issues...
  4. Proud Liberal

    Turnover Rates in Precision Machining

    I'm looking to benchmark turnover rates in a precision machining environment (automotive transmission components). Where would I go to get that type of info?
  5. Miner

    Intro to Measurement System Analysis (MSA) of Continuous Data – Part 1: What and Why?

    This is the first in a series of articles about MSA. The intent is to share a career’s worth of experience with measurement systems and their application in inspection, process control and continual improvement. Calibration, measurement uncertainty and attribute MSA are outside of the scope of...
  6. M

    Precision Machining Supplier Audit Format/Template wanted

    Hello All, I am a regular visitor of Elsmar and I can say I learned a lot on this website.. This is my 1st post to this forum (sorry for that :o)...I have some questions regarding auditing my suppliers on precision machining...Appreciate your advise.. I am currently working in a analytical...
  7. B

    Precision Machining and Compressed Control Limits

    Hi all, my company mills high purity graphite. Our customer has a tolerance window of +/- 0.0002". I read an article on this site "Statistical Process Control for Precision Machining Part 1", dated 12/2/08, by Bob Doering. In the article he describes how precision machining does not follow a...
  8. V

    Validation of Washing and Degreasing (Solvent Washer) for Precision Machine Parts

    Hi All, I work for a precision machining company and we are currently validating various pieces of equipment. We have a Washing unit that we use for washing and Degreasing (Solvent washer) of our parts. Our Customer has requested that we qualify/validate this piece of equipment. We are...
  9. P

    Received a minor for not having good measureables/goals. Need help with KPIs.

    "Top Management shall ensure that quality objectives to meet customer requirements are defined, established and maintained for relevant functions, processes and levels throughout the Organization. " So I recieved a minor on this clause. I need to get some measureables & goals together for...
  10. C

    Process Control Chart - Capable, but not stable question

    I have a control chart for a customer attached with Data and supporting CpK. I have a control chart that is out of control, so technically the Cpk value is not valid because you have to be stable before you can be capable. Any thoughts on this. I think it is beating a dead horse to try and...
  11. S

    Information required on camshaft machining

    Can anybody tell about the processing machines used for manufacturing forged camshafts
  12. L

    Calibration - Buying New Tools - How do you determine the next calibration date?

    Hi everyone, I am having a hard time finding anyone agree on how to handle calibration in general, so I thought I'd turn to you. I'm in precision machining, so we have all the standard stuff: calipers, thread/pin/height gages, micrometers, etc. Question: When we buy a new tool and it...
  13. K

    UDI Labeling for Medical Device Samples

    Are we required to UDI label medical device samples packs sent to customers for device evaluation? For example, P/N 970 Surgical Skin Markers 100/Box is UDI Labeled and listed on the GUDID Customers want to evaluate the markers before buying a large quantity, so we send a 5 Marker Sample Pack...
  14. bobdoering

    Precision Machining - Definition

    Precision Machining - a process where material is removed by a cutting surface, such as grinding, honing, turning, milling, etc. The process must be controlled in a manner that all variation (vibration, bearings, measurement error, etc.) is statistically insignificant except for tool wear.
  15. bobdoering

    Statistical process control for precision machining - Part 3 - Sampling Error

    SAMPLING ERROR WITH THE UNIFORM DISTRIBUTION It is good to understand what your process looks like over time (as in run chart). One problem with histograms is they can be easily fooled into thinking you have bi-modal distributions, normal distributions and tight distributions, when really you...
  16. H

    Equivalence within Medical Device Family

    Dear experts, Can we claim equivalency within the family of devices of the same manufacturer? Is it acceptable as per Meddev rev4 and MDR? The equivalent device will also be our device under evaluation covered under scope. To how far is it right? Do we have any other approach? Looking...
  17. T

    Book Recommendation for ISO 45001:2018

    Sorry if this has been asked before. I'm wondering if there's a book that you can recommend for 45001 standard that's equivalent to the Craig Cochrane ISO 9001: 2015 book that a few cove members recommended on here. I found that book helpful as a supplement to the actual standard and want the...
  18. H

    Bob's Statistical process control for precision machining

    Statistical process control for precision machining Part 1 Statistical process control for precision machining Part 2 Bob, thanks for sharing and for locating them 'together' in your blog to facilitate searches and users.
  19. bobdoering

    Statistical Process Control for Precision Machining - Part 2

    Is This Charting Accepted By The Big 3 Automotive OEMs? I have found that all customers (Big 3 and Japanese transplants) that I have trained on this concept (as a supplier) have accepted the concept, including its use for PPAP submissions. When it is all said and done, its simplicity makes it...
  20. bobdoering

    Statistical Process Control for Precision Machining - Part 1

    The unique requirements for control charting precision machining processes have been shared throughout many threads in the forum. I have decided to find a spot to put the concept all in one place. (This is just a brief overview. For more information, see the book CorrectSPC: When 'Normal' Is...
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