PC-DMIS experts, I have a part requiring surface profile dimensioning of dia 55mm mating surfaces. There are 10 mating locations (envision top-bottom/left-right). With our Absolute Arm, I laser scanned entire part (no contact). Resultant COP facilitates auto-feature extraction on nearly everything I need, but I don't know what to use for this. Center of mating surface is a square slot. I expect it's essentially controlling flatness and location/orientation (form/fit/function). How can I extract a 55mm diametrical surface data from COP and surface profile? Thanks in advance. If needed, I'll try to post relevant innocuous pictures.
You may be able to use the SELECT operator to segregate the sections of the COP you are interested in and then extract features from that segregated data. Need to see a drawing to be sure.
Thanks, Neil, for your reply. Ultimately, I might have to go that route. You're suggestions (in many other posts, along with others) have proven quite beneficial to me. When I ended up with millions of points in a single COP, I wanted to avoid creating 10 segregated locations like depicted in attached. Here's a cropped version of what I believe pertinent info.
Looking at the .pdf you shared I'd say that for each of the 6 mating surface locations you need to do the following...
Measure the square slot at the centre of the Ø55 mating surface area using 3 sample hits so as to capture the surface vector as well as the slot location. OR - if you've already scanned the part and are only extracting features, turn the ring-band on when extracting the square slot.
Create an alignment that levels ZPLUS to the slot (it's actually levelling to the vector you captured when taking the 3 sample hits). Also origin all three axes on the slot.
Add a circular SELECT Pointcloud Operator at X=0, Y=0, Z=0 I=0, J=0, K=1 with a diameter of 55. You can just add the command and type the values in afterwards but you will need to be in command mode to do this. The finished command would look like this...
Create a laser auto-plane with the COP reference set to COPSELECTION1 (or whatever your previous cop selection was called).
Reset the COP.
Recall original alignment.
Repeat for next mating surface location.
Once you have extracted planes for all 6 mating surface locations, insert a profile of a surface geometric tolerance command and pick all 6 planes from the feature list. Build the feature control frame by adding the 4mm tolerance and picking datums X,Y & Z and then click create. There is a total point limit of 200,000 for all of the datums and referenced features combined when using DEFAULT math so if you run into an error message, go to the reporting tab and select Least Squares for the feature math and datum math.
I noticed that they've applied a ±2mm tolerance to the Ø55 mating surface area - not sure how you're supposed to check that? You might want to create two geometric tolerance commands - one for planes extracted at Ø53 and one for planes extracted at Ø57.
