Long Term Measurement Logging for Machine Shop - Starting with a clean slate

Z

z28tt

I'm trying to figure out best practices for logging measurements long-term for our machine shop. I'd like to have measurement history available forever, by part number, dimension, or gage used.

Customer requirements allow reduced sampling based on capable processes, which of course reset when there is a non-conformance. Right now we use paper and excel logs. Problem is the measurements are saved by lot, rather than in a database that's on-going. All of our gaging is old school dials & verniers, other than the CMM, Optical Comparator, and Profilometer. There is no data entry other than our operators manually keying in measurements.

We're potentially getting Visual FAIR, which can make detailed inspection plans easier, and Op# specific worksheets for data entry, but it's still saved on a lot basis, rather than a running database. I could push for some SPC-capable gaging to try out in QC before rolling it out to the shop, but budget is tight. We've got about 300 gages in our calibration system (probably 50-100 variable gages, if you ignore ring/thread/blocks).

What do you guys use for data entry? I spoke with the Pro-Link guys at Eastec, and have read through the MeasurLink brochures. Since there's nothing in place yet, there's no legacy data to worry about, and I've got a clean slate to build something solid. I've been thinking about making a database in Access or PHP/MySQL, but don't really have time to become a programmer and develop something from scratch.
 

bobdoering

Stop X-bar/R Madness!!
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Re: Measurement logging for machine shop - clean slate

As far as collecting data, data logging software of any sort is OK. The only caveat is that all you are doing is collecting data. Outside of a record, it provides little value in an machining environment.

On the other hand SPC is great if you are doing production machining. It lets you know when to make adjustments or change tools - if done properly. SeeStatistical process control for precision machining Part 1 and Statistical process control for precision machining Part 2 for more information. If you are doing precision machining, do not waste your money on X-bar-R charting SPC software. It is incorrect statistically for SPC for precision machining. Unfortunately, most SPC software does not accommodate the correct statistical techniques.
 
Z

z28tt

Re: Measurement logging for machine shop - clean slate

Graphing is the least of my worries. I figured the tough part is getting the data into some universal format so I can manipulate it any way I choose. hi/low, CPK, SPC, MSA, etc... :) The more data I have available, the better I'll be able to get useful information from it. I'd love to say: "On 316 Stainless, we have a CPK of 2.2 for 6" diameter OD's and 1.2 for .200-.300" wide ID grooves. Then I can adjust sampling & inspection accordingly... Until the measurements are in a format I can use, it's all locked away... BTW (Bob) - I've read through your SPC for precision machining posts a few times in the last month. Very helpful - thanks!
 

bobdoering

Stop X-bar/R Madness!!
Trusted Information Resource
Re: Measurement logging for machine shop - clean slate

Graphing is the least of my worries. I figured the tough part is getting the data into some universal format so I can manipulate it any way I choose. hi/low, CPK, SPC, MSA, etc... :)

Here is a suggestion: MQ1 by Cebos. What you want is a place to put data, where it will come back out painlessly. That is essentially an elegant database. Thiers does not need Crystal Rpeorts, their report writer is very nice (last time I saw the system). Even if you can't afford it, check it out as a benchmark for other systems.

No, I do not own Cebos, but I have been a customer of the MQ1 software - and wish I was now!
 
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