centers of same feature from 2 different probes - don't match

I found why the results were not showing up in the program for the 2mm probe! There was a 2x30mm.PRB file in the folder that the program was in... i removed it, and now it is showing me the results!

i just ran a test and it seems that i have fixed my problem!! i don't know how that file got in there... but i finally found the issue. I am sooo happy to see that it was restricted to one folder because if it had messed up the last 4 months of this DV build... i would be in some deep $h!t....

ClayT: i was taught to use the largest dia ball on the shortest probe (the most robust probe) and use it as the "Master" for locating the cal. sphere. Say "yes" and let it do it's thing at A0B0. then run all the probes saying "no".

Thanks guys and gals for the help! This one had a happy ending.. just took all day to get there... and guess what... WE BEAT TECH SUPPORT!! no suprise there huh?

Sam

so you fixed it by placing a probe file in the right location?

I know this topic has been beat to death...

Here's how I do it. Am I doing it wrong or just wasting steps to achieve the same result?

Qualify the master stylus (1mm=A) at A0B0, answering YES.
Load stylus B (2mm) and qualify A0B0 answering YES.

Now both stylus A and stylus B are calibrated to the same location.

Then load A again and qualify A0B0, answering NO.
Then qualify the remaining angles for stylus A, answering NO.

Then load B again and qualify A0B0, answering NO.
Then qualify the remaining angles for stylus B, answering NO.

(If the answer is I'm an idiot, I'll take this to another thread so we don't hijack the OP.)

You'll get correlating probes but with unnecessary steps, only ever say Yes with one probe at A0B0 (If I was in charge of the setup I'd have MASTER in the file name but I'm not)

Here's why...

When you build a probe file demon knows the nominal size of every component in the build, and therefore the theoretical XYZ offset from the end of the CMM quill/ram to the centre of the Tip.

However, we all know nothing's ever manufactured perfectly, so what happens when you say 'Yes the sphere has moved', is that the demon takes that probe to be perfect. I don't know if you've noticed but when you say 'Yes the sphere has moved', if you view the qualification results it also has a line showing the XYZ position of the Qual Sphere relative to your CMM's home position.
A lot of people only look at the tip diameter and SD of their results, but it also shows the Theo XYZ offset and the Meas XYZ offset for each tip.

If you answer YES, your Meas offsets will equal your Theo offsets (i.e. that probe is 'perfect')

In effect any deviation from nominal in the probe build is actually transferred to the Qual sphere position.

When you qualify your next probe and say 'No, the sphere has not moved' the CMM will know well enough where the sphere is to qualify it, when you view the results you'll notice the Meas deviate from the Theo's, and now the two probes will relate correctly to each other.

Not exactly... the DMIS placed that file in the wrong folder somehow... that folder happened to be the one my part program was saved in... so it was blocking the program from seeing the calibration data that is kept in the "pc-dmis probes and programs" folder.. so i deleted the rogue file, and then it was able to pull the data from the appropriate folder. don't know how it works, or why... but it did.

now i just need to know why that file ended up there in the first place.

I am recalibrating the whole rack now, just to make sure everything is back to normal... fingers crossed.

sam

That should take care of the problem, I also do a Sphere check right after the Full calibration. Its a program that picks up my ALL my tips at 3 different angles and measures the Sphere, then I Dimension the results like DIA, X, Y Z, this way I can always tell if everything went ok during the calibration.

I also run the same Sphere check program frequently to make sure that the correlation between the tips stayed the same. Specially if I had a crash or something.

Glad to help!

there is another thing that I noticed, but I think it all depends on your machine and probing system. I was tough that if I want to add new probes or if I simply want to calibrate one or two tips, all I have to do is take my master probe calibrate it at A0B0, tell it "yes" the sphere has been moved, then calibrate all other tips at A0B0 then ADD new Angles and voila, all of my tips are correlated to each other.

But I am finding that this does not work with my set-up. I think it's a probing issue. Any one has noticed that?

That sphere check is a great idea wolfman... i was planning on coming up with a test that i could run to make sure that the tips all correllate not only on size dims, but also on the location of x,y,z... and your method is probly the simplest and most effective. Thanks, Sam

there is another thing that I noticed, but I think it all depends on your machine and probing system. I was tough that if I want to add new probes or if I simply want to calibrate one or two tips, all I have to do is take my master probe calibrate it at A0B0, tell it "yes" the sphere has been moved, then calibrate all other tips at A0B0 then ADD new Angles and voila, all of my tips are correlated to each other.

But I am finding that this does not work with my set-up. I think it's a probing issue. Any one has noticed that?

That bull excrement - for now each tip must be qualified individualy, I believe (but don't quote me on this) that it's in the pipe line to be able to qual several tips at specific angles and it will calculate the rest.

That bull excrement - for now each tip must be qualified individualy, I believe (but don't quote me on this) that it's in the pipe line to be able to qual several tips at specific angles and it will calculate the rest.

so you saying what? I am not sure I understood you