Best Practices for qualifying <1mm diameter stylii

[[Ri...]]

Just got my 8mm reference sphere in and figured while I wait for my <1mm diameter stylii to arrive I would inquire into best practices for qualifying them.

(Contura 7/10/6 RDS-C-CAA Vast XXT TL3)

From what I have been able to gather here on the forums:

1: No scanning. This will just yield broken stylii.
2: 6 Point Qualification

bBt aside from that, not much else. Probing forces, etc?
What else would you recommend I be are of when qualifying tiny probes? 👩‍🏫
Thank you!

[[Am...]]

How small is the probe? I have never done anything different for my 0.8mm stylus.

[[Ri...]]

You are going to qualify and measuring a probe smaller than 1mm the same way as a probe larger than 1mm.

Typically the only thing we will suggest is to turn down the probing dynamics. 10% on a 0.3mm 20-30% on a 0.5mm.

I've been scanning with 0.3mm with no issues.

You'll have to perform a Passive Qualification no matter what.

[[Al...]]

You will be scanning for the qualification, there's no going around it. There is no force adjustment on the XXT when qualifying, it will scan at 3 different levels automatically to obtain bending force parameters. You can select which of those 3 force levels to use for feature measurements in the program. Use sensitive for styli <1.0mm. You can select Geometry requal after you scan it.

Our 0.3mm stylus is the workhorse in our library and we rarely break one while qualifying or measuring a part, it happens while cleaning or replacing it. That being said, if you replace it you must re-qualify with scanning.

[[Ri...]]

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This is an incongruency I can't overlook.

there's another thread here that clearly states that scanning isn't possible with <1mm stylii.

I have a passive scanning system, it has no idea of the forces being applied, it's just a trigger break.
Are you sure you aren't talking about an active scanning system?

[[Ro...]]

I would argue that a 1mm stylus is the workhorse of the industry. i don't know if ive ever seen a cmm that didn't have one in its changer somewhere.
they are very durable, especially on an RDS setup where the styli is held in place with springs & magnets.
0.5mm is where i would start worrying about durability.

[[To...]]

I have scanned using 0.3mm dia probes on XXT sensors, too. Setting the Probing Force to sensitive means I am deflecting the stylus less (.1mm) than Standard(.15mm) and using 30% Probing Dynamic means I am approaching at a slower rate. These are both factors in longer probe life.

[[Al...]]

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I am also using a XXT TL3, which is a passive sensor, and scanning small diameter styli on initial qualification is required. I'm not sure what you mean by "a trigger break". It is not a touch probe.
The Contura comes with a 30mm sphere and you can't use that for small diameter styli but you can use a 25mm sphere if you use the Zeiss styli. Scanning always uses 180 degrees of coverage so a smaller sphere is needed for small diameter styli. That might be what the other thread was referring to.

[[Ri...]]

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The way it was explained to me just a few weeks ago in advanced class is that passive scanning is "exactly" like a trigger break on a touch probe. This is the same reason why i was told by the same instructor that you can't/shouldn't use self centering on passive systems. It doesn't sense actively, it just knows when its reached/past a threshold.

Did he teach us all wrong?! Great..

Getting a lot of conflicting information. ❓

I have a brand spankin new 8mm reference sphere and

.2mm
.5mm X 7mm to qualify
.8mm

according to this thread which I found on the topic:
viewtopic.php?f=11&t=1532&p=10139&hilit=75mn#p10139

Start with 75mn of probing force or less.
Probing dynamic at 50% and 180° if coverage is available.
6 point calibration/ Single points/ No Scanning

Final recommendation for a .2mm stylus qualification was:

25mn \ 10% \ 6 points \ 30%

[[To...]]

I'm curious how the XDT sensor works. It looks like an XXT sensor on the outside but it doesn't scan so I'm wondering if it is a "trigger" sensor.

[[Ma...]]

So I have been using a 10mm RUBY for my .5mm qualification, and I actually had NO problem with it qualifying accurately, because my company was too cheap to buy an 8mm sphere. However, one of the machine operators thought the 10mm ruby was huge *insert wide eyed machinist face here* and then...dropped it, therefor damaging it. But I never had an issue before then qualifying the probe on the ruby, at 100% force with my XXT head.

As far as how you can qualify the probe, you can qualify it just like any other probe, if you start to run into issues then I would start decreasing the force, however I do not think that you will have any problems. Also, I use my .5mm ruby to scan parts that are around 4in x 8in about twice a week, multiple parts (AQL 1.5 Sampling), and I never had many problems, I do use filtering, and one thing to DEFINITELY keep in mind when scanning with a .5mm probe, Pay attention to your speeds and feeds.

[[Ri...]]

UPDATED:

Solved, Got a call from an applications engineer who quickly helped me work through the variables.
Root Cause:
Turning down the speed knob with reduced probing dynamics generates drag sufficient to throw a collision alarm. Run at 100% speed, despite how it looks. (appears too fast)


I took a stab at qualifying my second smallest and most useful 0.5mmx14mm stylii
(626103-5444-014)
DK: 0.5mm
MLE: 2.3mm
ML: 5.0mm
L: 14.0mm
DSE: .3mm
DC: 1mm

I am getting a Collision alarm at the same location (rear left quadrant of the sphere) during the scanning portion of the qualification. Consistently.
As you can see from the images below of where the machine stops, it's not shanking out. (I have been watching visually as well)

A close up inspection under a microscope of both the probe and the ref sphere shows no apparent surface damage. Short of using some sort of penetrant to visualize any invisible cracks in either sphere, which doesn't sound advisable, I'm not sure where else to look.

Calypso is stating there's a crash during the scan portion of the qualification, which I am not seeing.
Though the scan speed seems "way too fast" for a probe of this size, I am running the speed knob at 25% to tame this.(Is there a better or correct way to compensate for this, if at all?)
I have tried 30%, 20%, and 10% probing dynamics, all set to "Sensitive" (speed knob 25%) with the same result:
33 Collision: Lost of Commands Possible 😡



moved to the hemisphere with white background to demonstrate shank clearance

I have an open ticket, but I start at 5:30am EST and IMT doesnt open till 8am Central.
Curious if anyone has any advice that might help to get me moving again instead of loosing the better part of my day.
as always thank you all for the hand holding sessions. 😜

[[Si...]]

Um.. I am about to setup a 0.5 Mm Probe... With the Base Cal Sphere... Should I not do this? See, Now I am confused... I already have Calibrated and used 0.8MM Probes.

[[Ri...]]

I've never had to change the default settings to qualify a 0.5mm. Anything smaller than that needs lower probing force, and low probing dynamics (10-20%)

[[Si...]]

Just received in our new 8MM Ref Sphere. How would I go about utilizing that for the calibration of .5MM or smaller Styli? My Default Ref Sphere it crashes due to the Small Shoulder on the .5 styli (which is why we bought an 8MM Sphere)

[[Ri...]]

Unless you are using large probes 5mm+, I would just use that reference sphere as your primary.

In the Stylus System Qualification window is a Reference Sphere Management option. That is where you will add your new one. You will need to qualify the MasterProbe on that Reference Sphere (in the right hand corner of the Stylus System Qualification window you have a drop down to select a different stylus system).

Just make sure that you always pay attention to which reference sphere is selected when qualifying probes.

[[Si...]]

Thanks!

[[Go...]]

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In particular, it is calibrated with the "sensitive" method and I modify the angle of coverage since the probe rod can have contact with the calibration sphere

[[Gr...]]

We have two Zeiss CMMs a Contura G2 with Vast XXT TL1 and a Accura2 with a Vast XXT TL3 head.
Both of these machines use a .25mm Stylus and we have had no problem qualifying this small of a stylus.
We use a 8mm reference sphere and 5mm master stylus to determine position of reference sphere on the table then qualify the small stylus with the Probing Behavior set at Sensitive and probing dynamics set to 50%.
We have not had a problem in 15 years doing it this way.
The only problem we have with these small stylus is seeing the little boogers, need a 10x magnifying hood.

[[Si...]]

Hi, I am having an issue. When I try to do a Geo Qual for my Master to the 8MM , an error pops up about possibly putting the SHAFT Radius to big. ays there may be a collision. Funny thing is, it does the Tensor no problem. I have a 8mm Master Probe, its all I have. I'm assuming that is the problem? Should I get a smaller Master Probe for this Reference sphere.

My Orientation is the default 135 degree.

[[Cl...]]

We have a program that uses a 0.5mm probe, (543 O-inspect) qualified at 20 percent probing dynamic.
That's the only way to keep from flexing the part. Just passed a Gage R&R in at less than 10 percent.

[[CA...]]

Hi,
I am trying to qualify 0.5mm or less.
My Doubt in VAST-XXT TL3 with RDS-CAA: is it recommended to use Sensitive + 50% Probing Dynamic?

[[To...]]

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I like to use 30% but I know others that use 50%. The issue will be some smaller probes don't have enough length of shank to be qualified on a 30mm reference sphere. Some do. I currently have a star probe with two 0.5 probes that I qualified on a 30mm ref sphere. I have not tried setting up a 0.5 probe in the CAA mode, but as long as it doesn't shank out, I can't see a problem. Your S or Sigma will likely be higher as a result of being a CAA stylus system. I often see anywhere between .0015 to .0020mm

If the stylus length is too short, you will need a smaller reference sphere. Try qualifying it as a single stylus first to see what your sigma value is. If it's low, then you're probably not shanking out.

[[CA...]]

Thanks Tom,
I have qualified the 0.5 Stylus under RDS-CAA, with a reference sphere 8mm, the S=0.0010. We used Sensitive and 50%.
Best regards