Qualifying a Disc Stylus

[[Za...]]

Hello all, I'm trying to qualify a disc stylus so we can inspect some features that aren't reachable with our normal styli setup. I've looked at many different references on the internet and these forums and I just haven't been able to figure this out yet. I'm using Calypso 6.6 and we have a Contura with a VAST-XXT scanning sensor. I know that Zeiss says we shouldn't use cylinder/disc styli with the XXT, but I know it's doable as we have a cylinder styli that was setup by the previous CMM programmer. I've tried both making it from scratch and copying another stylus system to do it and no luck yet. Does anybody have any guidance for me?

Thanks,

Zach

[[Ow...]]

Not sure who created this attached doc and I've never had to do it myself.
Good Luck

Stylus_Disc_Probe_for_VAST_XXT_.pdf

[[SH...]]

I have created the program one is using ring gauges according to the previous post PDF, I added loop to the program to check the repeatability.

And another one is using reference sphere, while using reference sphere first time you have to probe in the shaft Axis direction, then probe 8 point in two circular section 4 point each. First time you have to do it manually, then you can add the disc probe to your automatic prob calibration program and it will run automatically...I don't know reference sphere method is Zeiss approved but I am doing it .Up to now no problem, going well.

I run the ring gauge program weekly once. Reference sphere program daily i run.

I have attached a YouTube video about reference sphere calibration.
https://youtu.be/r9udZxsxtKU

[[To...]]

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I am the culprit...

The process of qualifying a disc probe on a VAST-XXT sensor is not "Zeiss Approved" as they do not support disc probes on XXT sensors. At most, this is a work around that allows you to collect some data that otherwise may not be possible. I support Zeiss if they don't support using a disc probe because I'm sure they have done the research and possibly found it is not up to their standards. If you do use a disc probe on an XXT using the method I described, you are doing so at you're own risk. However, I have seen results that are "acceptable to me", so I use this technique whenever I am comfortable with taking the risk.

[[Za...]]

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This is the method I've tried. I got the X, Y, and Radius values down below 20 millionths but the roundness feature won't come in under 50 millionths and this is a Class XX ring gage that I'm using. I'm also not entirely sure the Z is where it needs to be.

[[Za...]]

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I would like to use the reference sphere if possible, how do I even begin to set this up? Do I need to make a new qualification program or can I add it to the existing program with all of my other styli? I don't have a place for this stylus in my rack, but I want to be able to use it in future programs (we just started making a few different parts that all have similar features that will require this stylus).

[[SH...]]

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I am using activate sensor, so I added disc probe to on of my stylus systems tip no.5, calibrate it. Your case, I think you have to create a new stylus and calibrate it, yes you can add it your existing automatic probe calibration program. Iam not that much familer with xxt.

[[Ri...]]

No way you can just reach in with an L or T probe?

Disc Probes are terrible.

[[Za...]]

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I've never actually had to add a new stylus to the stylus system or to the qualification program. The only thing I've had to do is add different angles and I've never been able to get those to automatically qualify when I run my program either. I'm guessing this won't "scan" the sphere, but I just need to be able to do a Geometry qualification so I can get some reference points for our machine programmers to work with.

[[Za...]]

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I'm sure an L probe would work, but what are my limitations with the XXT sensor? And either way, I'm going to have to add a stylus to my stylus system and add it to my qualification program, which is the main thing I'm struggling with.

[[Ri...]]

Well... You are going to struggle with an "automatic" qualification for a Disc Probe on an XXT.

It's a cumbersome process, and majority of the time isn't worth it.

[[Za...]]

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The problem is that I'm going to need to use these for multiple parts coming up. An "L" stylus would work, but I didn't know if that was something that would work with the XXT.

[[SH...]]

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Your machine is a single probe head machine??I mean only XXT??

[[Za...]]

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Yes, XXT

[[SH...]]

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I have attached automatic probe calibration program pdf, I got it from this forum. Might be useful for you...

Probe Qualification Program 2018.pdf

[[Za...]]

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Thank you, I'll look through that and see what I can come up with.

[[Ri...]]

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Yes, there are limits on the XXT on how far you go outward. I don't have access to the PDF right now, so hopefully someone else can post it.

[[Za...]]

Okay, so I have the qualification program made, but I still think there is something wrong with how I setup the Z because it's not hitting the sphere along the equator.

[[Ma...]]

I created the video that Shabu shared. I have more information on how to calibrate the disc including editing the measurement data in the Stylus System Management window to get the correct disc value.

Mark

[[SH...]]

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Yes, that video was very useful......

[[Za...]]

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Mark, I feel like I'm close, but I'm just not entirely positive this is setup correctly. I would really feel better if I could touch off on the sphere and qualify that way, but I'm up for other options. I've been using a .625" Master XX ring to bring in my values and they don't seem very stable.

We have a family of parts that we are starting to make and they have these undercuts which require either a tiny L stylus or a disc stylus. The customer recommends a disc stylus and said that's how the previous supplier was checking them. I just don't know enough about the CMM yet to know the stylus limitations with the XXT. I'm still in the novice stages of my learning as I've only been doing this for about a year.

But any help you are able to provide is appreciated. 🙂

[[Ma...]]

Use the manual measurement and the first point is in the direction of the Stylus shaft to the masterball. Now probe 4 points slightly above the hemisphere of the masterball and 4 points slightly below the hemisphere of the masterball as shown in the video.

The nest step is to use the ring gage to make your size adjustment.

One more thought. I don’t believe you said what your probe system is. ZEISS does not recommend a disc with the XXT especially at a rotated articulation. I’ve used it in the straight down attitude with success.

Mark

[[Da...]]

You can't Cal a disc Probe on a XXT with out older software I think anything 4.8 and is not allowed but I don't totally remember.
you can also do it with a Renishaw trigger if you have the option on your RDS.

You can use something like this attached pic
I use M2 threads for small probe then adapt to M3 in to the XXT plate

Capture2.JPGCapture1.JPG

[[Za...]]

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Ahhh, Yeah I have the XXT and I'm trying to use it in the +Y and -Y direction. I need to probe the part from each direction. Maybe we'll have to figure out a different way to check this. Also, I don't have manual measurement as an option.