Tip of the Day 42: Part Sampling After the Fact

Returning to Part Sampling and Correlation…

One of our customers could not get the Part Sampling tool to start on a validated eDART (October 23, 2003 software release). We’re not yet sure why. It is supposed to be there. I wrote some help to him to get him going since he had a big DOE starting with a bunch of people looking over his shoulder.

This brings up the subject of what to do about part sampling if you forget to use the Part Sampling tool to mark the parts. We recommend that you always use it because it tells you exactly which part to take from the machine and lists the time stamps as each is sampled. Sometimes people forget and run through several runs and then have to go back and sort of retro-sample the parts. This can be done either on the eDART’s Summary Graph or on the Analyzer.

Or course you MUST record (on paper or a bag of parts) the shot time stamp at which each part group started. So here are the steps in brief:

  • The shot time stamp on the upper right corner of the Cycle Graph updates at the end of Injection Forward. Record this time at the start of the group and at each sample that you bag up afterwards.

    Remember to wait until Injection Forward goes OFF. You have until the next injection forward goes off to get it written down.

  • Enter a note on the summary graph at the shot time stamp at which the group of samples began. This is exactly what the Part Sampling tool does for you (as well as file breaks and rejecting parts – see Tip #34).

Part Sampling Entry without Part Sampling Tool

If you forget to run the the Part Sampling tool or it is not in the system or will not run then enter the sample groups manually on the Summary Graph as notes. Here’s how.

  1. Take note of the exact shot time for the parts that you actually removed from the machine. This is the shot time in the upper right corner of the cycle graph. It updates with the new shot time AT THE END OF INJECTION FORWARD.

  2. At some convenient time enter a note on the Summary Graph at that shot time. First position the cursor there and read the time stamp at the top. Then click “Notes” / “Add Note”. Verify that the time at the top of the note matches the time at which you first began taking parts from that run (which we call a “group”).

  3. To make a part entry the first line must be typed like this (use proper case and the colon):

         Start Group: N Shots

         Where you replace the N with the number of shots you have in the group.

  4. The second line in the note is the name of the group; e.g. Hi H – Low S – Low T

  5. You can add more comments to the rest of the note just like any other. For example you might put the actual hold pressure or speed level on the third and fourth lines. Of course the eDART records a lot of those settings in the data automatically (e.g. Average Value / Hold Pressure and Average Value / Fill Flow Rate).

  6. Save the note. Ensure that it gets saved (and does not have the “Not Saving Data” message). Here’s a sample:

You can also enter these notes later in the Analyzer on a windows computer if you do not have time to do it at the press. Just be sure you carefully mark the parts (bag them) and record the exact time stamp for each sample.