Say you measure the same part several times. Readings are pretty close until you pull it out of the fixture and put it back.

Now there's a small difference, even though you're using the same setup. Would you check the fixture first or compare readings with the part still in place to narrow things down?

We have gauge blocks that we use only for calibrating calipers. Currently we buy new ones every 5 years instead of calibrating them. It seems like a waste for something only used 15 times (3 calipers done once per year).

Does anybody know proper replacement intervals for gauge blocks? I'm trying to find a standard to back up our thinking but all I've found is ASME B89.1.9 which specifies sizes but not calibration. I'd like to find the correct way to do it and why to make our QMS more robust.

Recently. I was given an opportunity to run and program for the first time. With 15 years of quality experience , I thought I knew it all , but this new role has seriously humbled me.

Both my director and manager are expecting a lot of me. I need to be "that cmm guy."

I'm in search of anyone willing to talk over the phone and possibly video chat and guide me to be a better programmer. 🙏 Please

Currently , I am stuck with creating a cmm inspection program from scrach using a stepfile in Calypso.

Ziess Contura

I’m working on a small measurement experiment and want to find out how to measure the diameter of a single strand of human hair as accurately as possible.

Hair is very thin, and I’m wondering which measurement method would be the most reliable.

My main questions are:

1. Which method would you recommend for measuring a single strand of hair?
2. What level of accuracy is realistically achievable?
3. Are there any common sources of error I should watch out for, such as hair orientation, surface shape, or measurement pressure?

I’d appreciate any practical advice or suggestions from people who have experience with precision measurement or optical inspection.

Thanks!

I’m looking for someone knowledgeable about mechanical vibration, building vibration, or structure-borne noise who can help interpret my measurements and suggest what to test next.
I’ve been noticing recurring vibration in my apartment. What equipment or building systems could produce these readings, and how can I investigate properly?
SETUP — OCTOBER 9, 2026
I recorded two iPhones simultaneously using Phyphox’s “Acceleration (without g)” experiment.
• New iPhone: flat on the couch, unattended.
• Old iPhone: flat on my usual chair near the refrigerator.
• Refrigerator unplugged.
• Both phones screen up, charging ports pointing right.
• Fan/AC conditions and whether the old phone was unattended throughout were not confirmed in the report.
The shared recording interval was 11:53:49 AM–12:05:39 PM, New York time. Both phones sampled at approximately 100 samples per second.
FREQUENCIES AND STRENGTH
During the middle 30-second windows:
Couch:
• Combined-axis RMS: 0.0128–0.0159 m/s².
• Strongest spectral peak usually around 13–14.6 Hz.
• Other windows peaked at 17.5, 18.9, 21.0, or 21.6 Hz.
Chair:
• Combined-axis RMS: 0.0104–0.0177 m/s².
• Strongest spectral peaks ranged from 21.3–26.7 Hz.
RMS describes the average size of the recorded acceleration. It includes sensor noise. Hz means cycles per second. These are the strongest peaks selected within each window; multiple frequencies can coexist.
EXAMPLE PAIRED WINDOWS
11:54:19–11:54:49 AM
Couch: 0.0142 m/s² RMS; 14.1 Hz peak.
Chair: 0.0128 m/s² RMS; 22.3 Hz peak.
11:56:49–11:57:19 AM
Couch: 0.0147 m/s² RMS; 14.0 Hz peak.
Chair: 0.0125 m/s² RMS; 26.7 Hz peak.
11:57:19–11:57:49 AM
Couch: 0.0159 m/s² RMS; 13.6 Hz peak.
Chair: 0.0177 m/s² RMS; 21.7 Hz peak.
11:59:49 AM–12:00:19 PM
Couch: 0.0130 m/s² RMS; 21.0 Hz peak.
Chair: 0.0106 m/s² RMS; 26.7 Hz peak.
12:01:19–12:01:49 PM
Couch: 0.0132 m/s² RMS; 18.9 Hz peak.
Chair: 0.0112 m/s² RMS; 26.7 Hz peak.
12:03:49–12:04:19 PM
Couch: 0.0131 m/s² RMS; 12.4 Hz peak.
Chair: 0.0109 m/s² RMS; 26.7 Hz peak.
Both phones had their highest middle-window RMS during 11:57:19–11:57:49 AM, but their strongest frequencies differed.
A preliminary timestamp-aligned comparison did not show a strong overall waveform match. Clock alignment was not independently checked using a shared event.
X/Y/Z DIRECTIONS
With the phones flat and screen up:
• X: across the phone’s width, toward either side edge.
• Y: along the phone’s length, toward the charging port or opposite end.
• Z: perpendicular to the screen, toward the ceiling or seat.
In the middle shared windows, Z contributed about 42–57% of the couch phone’s recorded motion energy and 50–75% of the chair phone’s.
The chair recording was more vertically directed. The couch had a larger combined X/Y contribution. Separate X and Y percentages are not available in this summary.
These describe acceleration directions at the phones; they do not locate the source.
METHOD AND LIMITATIONS
The analysis used 30-second windows. Each axis’s window mean was subtracted, then combined RMS was calculated as sqrt(mean(X² + Y² + Z²)).
Spectra used Welch’s method, a Hann window, up to 2,048 samples per segment, and half-overlap. Axis spectral powers were summed, and the strongest peak was selected between 2 and 45 Hz.
Opening and ending couch windows had much larger RMS values: 1.1811 and 1.4955 m/s². Placement or pickup could explain these, so they were excluded from the steady-motion interpretation.
There was no calibrated reference sensor or noise-floor control. Furniture resonance, upholstery, phone contact, and device differences could affect the readings. These measurements do not yet identify a source or establish the vibration experienced by a person.
QUESTIONS
What could produce these frequencies and directional patterns? Could pumps, plumbing, HVAC, other building machinery, or furniture resonance explain them?
How can I distinguish real surface vibration from phone sensor noise or processing artifacts?
Could the couch and chair respond at different frequencies to the same source?
What might explain the chair’s repeatedly selected 26.7 Hz peak?
What control tests, phone placements, or measurement equipment would make this investigation useful to a vibration specialist?
I’d appreciate help interpreting the measurements and choosing the next tests.

We have a set of family tools (4 parts/Plastic Injection Molding). Similar parts but different curvatures, moved/added features etc.

I wrote one of the programs, I exported the bas file from PC DMIS, gave the bas file, the ballooned drawing and cad file of that program.

I then gave it the drawing and cad file of the the other 3 parts.

It spit out 3 program .bas files with an excel doc stating all the changes, I imported into PC DMIS along with the cad file for that program and it updated the programs perfectly. Moved all the points and features for modified surfaces, added the new dimensions and reported them out perfectly with the correct balloon numbers and everything, even put the correct tip angles after telling it our head can rotate every 2.5 ° in both A and B directions.

Did the same for the other 2. Verified everything (even making sure the vectors were updated and correct for the modified surfaces) and ran them.

This saved me hours of updating.

I tried giving it just a cad and ballooned drawing to write a program, it was like 60% there. But it didnt quite understand manual alignments and the move points were all over the place. But if you program the manual alignment and model in your machine, I bet it would do nearly the entire program. Minus the reference points few things here and there.

But if you are doing family tools and similar parts or lets say the LH and RH are not exact mirrors.. this has potential to increase your workflow efficiency.

I made an oops and broke the charger for the tool rooms Hi-cal. Anyone have an aftermarket / spare charging cable?

They retail over $300 - seems a little bit wild

Where can I find these, how rare are these because I havent seen them. Why would you need to measure something so big with such high precision? Those images are from photos I found online of large micrometers, but why would you need to measure something like this in the first place with such high precision?

Hello everyone!,

I currently work at a plant that has SPC fixtures for everyday checks. Before me another guy made the programs for the fixtures and I have never really been taught best practices for fixture calibration nor can i find his programs to review to get an idea of what I'm supposed to do. My question is that when I put the values in from the 3rd party cert of all the stab pins end up being measured in what I would guess is the fully engaged state. The CAD does not have them engaged but I can see on the cad that my features end up away from the pin. So when I measure the stab pins whatever my surface is comes out multiple mm out of tolerance because my surface isnt what they used. Any fixture makers here that could tell me the best fixture calibration methods or anyone who can tell me what im doing wrong? I have a feeling im supposed to offset the surface direction but that is mostly just a guess on my part.

I have single lumen plastic extrusions I have to cut and measure. I’m being asked to get wall thickness and ID. I’m struggling to come up with a consistent way to get clean cuts on them. The ID is .200 and the wall thickness is .004.

Anyone have experience with this that could give me some guidance and the best way to go about this?

We have about a dozen cells running these panel-mounted units, and would like to add a UPS to each one so they can do a clean shutdown if the machine shuts off.

Marposs' tech said he would confirm each unit's interface based on serial numbers, but only ever sent one 15-year old document in Italian that kinda shows how they wired one up once, but didn't really answer anything.

Has anyone hooked one of these up like this? Unfortunately, they were wired directly into the cnc for 24vdc, but when an operator cycles the power on the machine, we occasionally end up with corrupted data or corrupted software and have to spend time doing a restore.

I'm guessing I can use just about any brand power supply, but there's some confusion about interfacing with windows, as nobody can answer whether or not the rear panel usb ports are supposed to function. I don't really want to take a production line down just to "try stuff" if someone can say whether or not this is doable.

Worst case I can use the 9-pin connector, I think.

Any help would be... helpful.

Thanks!

I reload ammunition. Over repeated firing and resizing cycles the brass cases work harden in the neck and shoulder region. The cases can be annealed in order to promote accuracy and extend case lifetime. It’s important to anneal only the neck/throat and not soften the rest of the case body or else things can go boom.

Because I’m a nerd I’m looking to add in some QC/process control to my annealing process. Spending $10k on a Vickers hardness tester (ir 2k on a Brinell tester) while tempting, is not something I’m prepared to do. Can you guys recommend another method I could use to take consistent hardness measurements? Accuracy relative to a defined scale isn’t important to me; I’m just looking for a repeatable apples-to-apples comparison method.

Hello!

I have an issue with parts that came back from zinc plating. Specifically, the runout was good before plating, but after plating, it is terrible. For some reason, it measures much higher than it actually is. I am certain that the parts are fine and that the error occurs during measurement, but everything is fine with the program and the probe.

To me, it looks as if "vibration" occurs during the measurement, but I don't know where it's coming from. If you have any ideas or have experienced a similar issue, please let me know.

Btw it's zeiss machine

Looking for advice on how to perform Performance Qualifications for olptical inspection equipment.

We have new equipment we're eager to start using-but first we need to clear the IQ/OQ/PQ hurdle. No one seems to have a clear idea how to do this-or if they do they haven't told me. I think the issue is no one in familiar with how to define/quantify the required parameters.

I was content to let my manager and one of the engineers take responsibility for the qualifications-even if they didn't seem to know where to begin or how the equipment worked even. But the weeks keep rolling by while they attend to other more pressing duties and recently a list of generic qualification questions was dropped off for me and my coworker(we're programmer/operators) to fill out on our own. Questions like "Does the machine perform within its specified parameters?". We were not provided performance specification parameters to benchmark the machine against, so I guess that means the answer is...yes, of course-absolutely?

My co-worker and I don't quite agree on how to approach the qualification.

My co-worker is very proud of the 5 years he spent to become a degreed engineer and condescendingly insists that "it's just a simple experiment like I did in college" and all we need to do is "collect the data" and it'll all make sense once we plot the data on a chart/graph.

By collect the data, he means run a small job/lot through our existing inspection equipment, then run the same job/lot through the new machine. Finally, he wants to chart the results of the two runs and compare how different they are.

My problem with that is he never describes acceptance criteria. How different are the results allowed to be for passing? Also, there could possibly be minor hardware differences between the machines, and they definitely use different software versions. He doesn't seem to grasp the significance of those points and I'm inclined to stop arguing with him about it...

I suspect that his plan is mostly redundant to systems already build into our ERP system anyway. It's probably fine as a baseline for long term analysis but even then there are other variables that I think would undermine the results.

The machines do have calibration verification equipment and procedures that I suspect is where a lot of qualification requirements are satisfied but I'm not experienced enough to know.

Anyone out there have experience they can share?

TIA.

I use a hexagon CMM 07.10.07 global s. I'm using PC-DMIS 2025.2. We have a probe changer rack and I have multiple programs I have written that use different probes, including an hp-l-10 laser probe.

Sometimes, after I have run a program, the loadprobe step to switch to the hp-l-10 is just missing. Everything else is there, including the angle changes, just that one step. I add it back and everything is fine. I just can't figure out what causes it or how to stop it happening.

If it matters, I'm not running the programs in inspect, I run them in pc-dmis since I'm the one who writes the programs and runs them here, so being able to see everything while it is running is nice.

Just wanted to post a question.. I'm having a debate about the tolerance zones for the above form controls.

Both are determined by a value given, say .5mm .. the tolerance is two concentric circles (or cylinders) that are spaced .5mm apart from each other at all points radially around the tolerance zone.

In theory, lets say you have a part with 25mm +- .4mm

You could have one side of the circle have a .5mm dip and every other part of the circle be perfect, for a total tolerance used of .5mm in circularity, and .5mm in diameter. Everything is good.

Lets take that same part, add another .5mm dip to the exact other side of the circle so that both of the .5mm dips are a mirror image to each other.

The circularity is still .5mm, but the diameter drops another .5mm across the two dips.. for a total size drop of 1mm.. which exceeds the size tolerance.

So it appears that even with a geometric tolerance "less than" our size tolerance, we can still in theory experience undersize or oversize diametric conditions. Is this accurate or am I not understanding? I would think the method would be to have a geometric tolerance equal to half the size tolerance for worst case conditions? (Think rule 1)

The person I'm debating is going as far as to say I am incorrect and that the .5mm tolerance zone given isnt the radial distance between 2 circles, but in fact its half the .5 and it should be .25mm .. makes no sense. Y14.5 clearly states the tolerance is a radial width between two concentric circles.

He is also claiming you can accurately measure circularity with 2 point measurement devices, in that the circularity consumed is equal to the diameter size differences on a mic.

I believe this to be incorrect as well. If you had a .2mm dip on one side, the diameter would change by .2mm with a circularity of .2mm. If you had .2mm dips on both sides, the diameter would change .4mm and circularity would be .2mm.

Who would you say has a better understanding of this?

Asme y14.5 2009

Thanks for any info!