CMM Stylus Material Guide

[[Iv...]]

Hey guys,

I put this quick guide together on stylus materials — figured it might be useful to have around the shop. Nothing too fancy, but it gives a simple breakdown of which styli work best for different situations, and a couple of reminders on wear and care.

Figured this might be old news for most of you, but maybe it could help some of the entry-level users and peers around the shop. It's a single page, so it would be easy to have it near your CMM. 

Give it a look when you get a chance — and hopefully it saves us some time (and a few styli) down the road. Let me know if you feel like anything needs to be edited. 

CMM Styli Guide ZF.pdf

[[Ch...]]

Ivan,  

 

 Thank you - well done , sir. Stylus material is very important.

 

 Tip : there is also sapphire stylus however these are more rare, they are nearly identical to ruby, however might have a blue/purple color if you prefer over red  😁  

 

Cheers, and happy measuring !!

[[Ow...]]

Nice work!

I'll add in that the extensions used on the styli are critical as well, especially on long extensions.

You usually get what you pay for and while expensive, the silver high-end Carbon fiber Zeiss Reach CFX extensions are worth their weight in gold.

I've used the cheaper, long carbon fiber extensions sold by other styli providers and their rigidness is not the same.

 

[[Iv...]]

@Chris Rotolo

Thank you, kind sir. 

Interesting, I was unaware of a sapphire stylus being an option. I considered including the tungsten carbide material, but I felt that it's really its own niche field, as it's most commonly used for gear measurement. I figured if you're already in that club, you probably don't need this info 😅

[[Iv...]]

@Owen Long

Thank you, I appreciate it. I would eventually like to add extensions to the guide; they go hand in hand. But I was one trying to keep this condensed to a single page, you can't rely on people flipping over the page these days 😂

Also, more importantly, this guide was driven by an RCCA. We measure a surprisingly high amount of silicon carbide, a very unforgiving material for those unfamiliar. Luckily or unluckily, it doesn't take too long to become familiar with the stylus (hopefully). However, with new programmers/operators, I'm not as diligent in expressing this knowledge and concern. Further story below for those interested. 

Also, I agree with you completely about your thoughts on extensions. ZEISS is completely in its own league. Cost will always be a factor, so like you, I've tried the other brands. But in this area, I would agree that it's really one of the areas where you need to spend up. More often than not, I find myself breaking down other stylus systems so I can use the ZEISS extensions rather than using off-brand ones that are just sitting there. 

Recently, in our lab, we had a job involving silicon carbide — a highly abrasive material. A programmer, unfamiliar with its properties, began scanning the surface with a silicon nitride stylus. By the time I caught on, multiple scans had already been completed. To the naked eye, the stylus looked fine. But when we pulled it under a microscope, a flat spot was immediately visible. The lesson? Styli wear is real, and it can happen faster than you think — even when you can’t see it.

I didn't intend to toot my own horn with this post. But I made a LinkedIn article with the full story. Ultimately, the goal is to use this article and RCCA to push for the purchase of more diamond styli 😁

[[Wo...]]

Please sign in to view this quote.

Had the same situation. Had to re-measure ~50 pcs again. The top of the sphere was worn 0.002". Curiously, the Tensor calibration was not picking it up as it doesn't hit the sphere with the top of the probe (geometry re-qualification does). At the time it was decided that we're going to stick to ruby probes as silicon carbide was giving us too many issues.

 

Please sign in to view this quote.

Thanks to the above situation I've convinced the boss to get a diamond 3mm probe with carbide shank - it's an indestructible beast 😄

[[Za...]]

Ivan's PDF looks really valuable, and for anyone visiting this post in the future, below is a link to a Knowledge Base Article which has a more in depth Styli Guide
https://portal.zeiss.com/knowledge-base?id=1113662

[[Iv...]]

@Zak Stehlin

Thanks! I agree that it is a deeper dive and more insightful for anyone looking for a comprehensive view of everything stylus-related. My only issue with the guide is that it is a little drawn out, which causes some people to tune out. 

I believe the target audience for the guide I created is operators and entry-to mid-level programmers. I felt that they benefit best from smaller, bite-sized guides.

[[Lu...]]

Is there a way to clean the build-up from styli?

[[To...]]

Please sign in to view this username.

  I read a post (not on this forum) that they used lye (sodium hydroxide or potassium hydroxide).  CAUTION  Read up on these chemicals before using.

Edited September 23

[[Ch...]]

Please sign in to view this quote.

Please sign in to view this username.

What I'm about to say is considered blasphemy.  But you can clean aluminum build up off ruby probes by using extra fine scotch brite and alcohol.  Then cleaning with lint a lint free cloth. 

I admit, it is possible to remove material by being too aggressive with the scotch bright.  But I have good data to support that it's not nearly as bad as people claim.  I'll check our high use probes that have been cleaned many times using this method using our Zeiss microscope, Keyence Microscope, and using the Styli Roundness Scan that is attached.  I have not found any significant wear that I can attribute to the scotch bright cleaning.  

 

Derek Stedman originally contributed the roundness scan and I make no claims to have created it.  But it's a really cool program that checks the probe against the reference sphere and outputs roundness plots for your probes.   

Styli Roundness Scan.zip

[[Wo...]]

I think I've seen a post somewhere about using muriatic acid to clean aluminum off ruby, but it was so long ago it might have been on the old forums. Never tried it though. In general, when I see a significant buildup that's affecting measurement I will just replace the probe. But I don't have the machines scanning aluminum 24/7 so it doesn't happen often. 

Please sign in to view this username.

 Could you give some more info about that program? Do I just locate the reference sphere with a master probe and then just run it using position points only like a probe qualification plan?

[[Ch...]]

Please sign in to view this username.

Kinda, you'll locate the reference sphere like normal.  Then the program has PCM in the program that will drive your probe into the reference sphere and output roundness plots to see any wear on the probe. 

 

[[Iv...]]

I'm happy, people are still getting use out of this thread! 

Please sign in to view this username.

 ZEISS's ultimate recommendation is to replace the stylus if the buildup can not be fully cleaned up using a light cleaning solution. Maybe I'm just connecting dots, but it's a little convenient for them to say this since most will probably get the replacement from ZEISS 😆

A little while ago, I heard about a new automated cleaning brush that ZEISS was releasing. I couldn't find it available in the United States, but it appears to be available in other countries. But this looks more focused on cleaning a stylus, and it would not remove aluminum buildup. 

Admittedly, I have not been too aggressive in this area. My general cleaning solution is isopropyl alcohol. Working in California makes it difficult to hold any harsher chemicals, especially on your worksite. My general protocol is to use the proper stylus material for the part. Obviously, this doesn't always work out. I'll still keep styli with buildup and use those more comfortable jobs where I can justify the uncertainty in the buildup. 

Side note, I have used muriatic acid (Hydrochloric acid) to remove aluminum buildup from thread gages. You could see the reaction immediately happen, and I think those thread gauges eventually failed when the calibration was due. So I wouldn't recommend it for cleaning styli. 

[[Iv...]]

Please sign in to view this username.

 Interesting! I definitely give that a download and check out the Styli Roundness Scan recipe. Have you found that it can properly detect aluminum buildup?

Also, what is the smallest diameter that you are comfortable using Scotch-Brite with? 

[[Ch...]]

Please sign in to view this username.

Under 1.5mm it gets difficult to use the Scotch Brite.  We use it on some of our .8mm probes, but you have to be careful, and it is less effective.  For anything 3mm and above it works great.  

You have to make sure to get 'extra fine' or 'ultra fine' scotch brite.  usually its called 'extra fine hand pads' or something.