I work in a facility where we make transmission insulators for power lines. We have to measure what they call leakage per customer drawing. We recently purchased a CMM machine and now EVERYONE wants EVERYTHING checked on it. Of course it's a new toy I get it. But I am trying to perform a scan without the model to measure leakage, but I am drawing a blank on how to measure them length of the actual scan that has traveled over the surface of the part. I tried it with free form scan, as well as linear open. Attached is a photo of the part thanks in advance for the help!
Maybe something like :
ASSIGN/V1=SCN1.HIT[1..(SCN1.NUMHITS-1)].XYZ
ASSIGN/V2=SCN1.HIT[2..SCN1.NUMHITS].XYZ
ASSIGN/V3=SQRT(DOT(V2-V1,V2-V1))
ASSIGN/V4=SUM(V3)
Should work witout looping.
Or directly :
ASSIGN/LENGTH=SUM(SQRT(DOT(SCN1.HIT[2..SCN1.NUMHITS].XYZ-SCN1.HIT[1..(SCN1.NUMHITS-1)].XYZ,SCN1.HIT[2..SCN1.NUMHITS].XYZ-SCN1.HIT[1..(SCN1.NUMHITS-1)].XYZ)))
To make it works, you need to use a large decimal places, otherwise you will add a sum of zero !
Thanks! I'll give it a try right now, give me something to do while I wait on production on this long boring Sunday haha. I have the machine set to 5 decimal places. We do most everything in inches. Should that be enough or do I need to move it out further than that?
Depends on the distance between hits (scan density).
You can increase the value just before the assignment, then decrease after the result, it doesn't change anything on the prog !
Good luck for this boring sunday !
Path definition tab density is .10 suggestions on what to change it to? Settings tab point density 10 points/mm offset force .06 N Acceleration 10 mm/sec squared scan speed 10 mm/sec anything I need to change? Also I have the machine set to 7 decimal places sum is still zero
Or insert a comment / operator with each assignment after V1,V2,V3 and v4 ?
And change ASSIGN/V3=SQRT(DOT(V2-V1,V2-V1)) by
ASSIGN/V3=DOT(V2-V1,V2-V1)
ASSIGN/V4=SQRT(V3)
ASSIGN/V5=SUM(V4)
I executed the scan and tried to insert the code. Unfortunately my day is coming to a close. I will begin working on it again first thing in the morning. I will post the code in the morning and attach screen shots of my screen showing the settings in my tabs. Thank you for your help! By the way how did you learn those codes? I am just now cutting my teeth on PC-DMIS are there courses I can take to learn them?
Some explanations about the code, because I don't understand why it gives zero...
ASSIGN/V1=SCN1.HIT[1..(SCN1.NUMHITS-1)].XYZ .....................................is an array of (scn1.numhits - 1) points, from the first to before the last.
ASSIGN/V2=SCN1.HIT[2..SCN1.NUMHITS].XYZ ...........................................is an array of (scn1.numhits - 1) points, from the second to the last.
ASSIGN/V3=V2-V1 .........................................................................................is an array of (scn1.numhits - 1) vectors
ASSIGN/V4=DOT(V3,V3).................................................................................is an array of squared values of lengthes ((scn1.numhits - 1) values)
ASSIGN/V5=SQRT(V4)....................................................................................is an array of (scn1.numhits - 1) values of lengthes
ASSIGN/V6=SUM(V5)......................................................................................should be the length of the scan.
With 10 points by mm, you should obtain in V4 an array of values around 0.0000155", so not "0" if you use 7 decimal places.
I think you should check the syntax...
And try with a scan density larger, without changing the decimal place (just to check the code (1point/mm) for example)
Does your scan is called "SCN1" ???????
