[Li...] Posted Sunday at 03:21 PM Share Posted Sunday at 03:21 PM Good morning, all! I have some questions and some venting to do here. LOL! We are having a company machine 3 impellers for us currently. They use PC-DMIS at this machine shop. Their programmer was able to export all the points throughout the CMM program. He has created a program that has 934 points. The one impeller has 3 blades that curve from top all the way to the bottom base of the impeller and 3 "splitter" blades. He is probing the top and bottom of each blade along with points along the edge. This is per the note section of the drawing. The exported file from his program is an XYZ file that I have put into excel. My boss and our lead SQE are adamant that he and I are "apples to apples" when it comes to the points he uses and I use, which is fine. I am just creating a point and copy/pasting XYZ, IJK. Just a lot of ctrl c, ctrl v action....lol! 5604 times! If I understood him correctly, he won't report each point individually, rather collect them all as a group and it would "in the background" get high/low deviation and he said that it will add those two results together. So it wont do max deviation x2 "profile". I will ask him about this just to re-verify. -Question #1 What can I do in Calypso to match something like this? I have 19 points pulled into a plane (recall feature points) then selected it in a Profile characteristic and did two results min/max. This result won't be "apples to apples" on a report like my team wants and expects to see. I may need to have the other programmer change what and how his program reports. -Question #2 (for those who have PC-DMIS knowledge) With myself and the PC-DMIS programmer are using the same inspection fixture, the same alignment points per CAD model points, will this result in these two different CMM software's give the same data? Is it possible for Calypso and PC-DMIS to report the same data, at least within a few tenths? When the most important items needed are present, i.e. fixture, datum scheme, and the same exact points. Link to comment Share on other sites More sharing options...
[Cl...] Posted yesterday at 11:54 AM Share Posted yesterday at 11:54 AM You could pull all Those points into a Maximum and or Minimum feature construction and that would give you the max or min point. Link to comment Share on other sites More sharing options...
[Li...] Posted yesterday at 04:55 PM Author Share Posted yesterday at 04:55 PM When I got to a certain point in the program after copy/pasting the nominal XYZ, IJK the PC-DMIS programmer was able to supply me I decided to create a few characteristics and run the program. This is being ran on my offline seat so what should have happened was to basically populate nominal data. Well, when I did this, I got big deviations on the 3 profile char. I made in the program. I have no idea what is causing this. Then I added a point using Calypso and I got what I would expect, zero deviation. There must be some sort of disconnect from PC-DMIS nominals/vectors and Calypso. Link to comment Share on other sites More sharing options...
[DW...] Posted yesterday at 06:22 PM Share Posted yesterday at 06:22 PM Please sign in to view this quote. See attached. Influences on Measuring Results.pdf Link to comment Share on other sites More sharing options...
[Aa...] Posted yesterday at 07:36 PM Share Posted yesterday at 07:36 PM Please sign in to view this quote. That's a nice graphic. In my humble opinion, by far the biggest influence is the lack of proper design tolerancing. Almost everything I see is more or less incomplete, ambiguous, illogical, or impossible. Yet all vested parties insist on moving forward with dimensional inspections so that they can see "where we're at". And from then on, it's garbage in garbage out. Improper design tolerancing forces the inspection programmer to fill in the missing information, or patch over impossible tasks. Each programmer will interpret and perform this effort differently, leading to a variety of unstable possible outcomes. Link to comment Share on other sites More sharing options...
[na...] Posted 13 hours ago Share Posted 13 hours ago Please sign in to view this quote. Very well put. Agrees, thanks. Link to comment Share on other sites More sharing options...
[Li...] Posted 6 hours ago Author Share Posted 6 hours ago Please sign in to view this quote. Yes, but our report/data won't match because PC-DMIS will take min/max deviation and add those together. This is how PC-DMIS calculates profile according to the programmer at our supplier making these impellers. Link to comment Share on other sites More sharing options...
[Ke...] Posted 6 hours ago Share Posted 6 hours ago Please sign in to view this quote. I wonder if they are using bilateral with two results, instead of with one result (which is max deviationx2)... or if they are using an old version Link to comment Share on other sites More sharing options...
[Li...] Posted 6 hours ago Author Share Posted 6 hours ago Please sign in to view this quote. I will ask him about this. According to your screenshot he should be able to do max dev x2 for profile. However, he stated that it uses all the points taken on a surface to get these results. I would be more prone to using space point distances, essentially on the impeller, there are no planes on this part, at least on the 6 blades that are on this impeller. Link to comment Share on other sites More sharing options...
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