Torus Diameter

[[To...]]

Any and all suggestion to measure this torus and report the 2.0933" ±.0006" diameter at the bottom of the torus (as shown below)

Diameter is 2.0933" ±.0006"
Torus R2 is .041 ±.0011"

Obviously, I can measure a torus and calculate the diameter but does that give me the best results?

Screenshot 2022-11-10 144246.jpg

[[Ri...]]

I've measured the taurus and then used its centerline to scan the minor.
I have had success doing that.

[[Ja...]]

Check circles at different heights around that center and report the smallest diameter.
This can further be improved resulting in lesser checks if you can use a probe with self-centering probing for a space point at the center of torus in direction of one of the CMM axes. Get that height and measure circles around that height in small calculated increments and report the smallest diameter with tighter tolerance to take error due to height increment into account, if any.


I would also put a check in place that MIN(diameters of top most and bottom most circles) is greater than MIN(all diameters) to validate your result.

[[Ke...]]

I have used a torus to align the diameter and I have also used self centering circle paths to take direct measurements.
If the form of the torus is good, then the calculated diameter was usially within a couple of microns of the measured diameters, on the parts I compared values on (the parts I measured typically had a roundness of within 5 microns)

[[To...]]

What do you think of measuring the torus with a bunch of "small circle paths" and then recalling the points into a circle and evaluating Max Inscribed??? I think I would use more circle paths, too.

Screenshot 2022-11-15 114209.jpg

[[SH...]]

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I think repeatability and reproducibility will be very poor,
What about calculating the valley point using a curve,then calculating the co-ordinate value of that point and creating section in the model... At that point...

[[Ke...]]

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I considered this (and I'm sure it would work fine), but I prefer to only use 3-4 (D2) paths to locate the torus, and then directly measure the diameter (D1). Less measurement time, and then I have data for 2 pt diameter and/or roundness.

[[To...]]

Curious. How much does a self-centering path really impact the measurement when the bottom is almost flat, unlike a v-groove?
D2=.082" and probe diameter = .059"

[[To...]]

A plot twist. Actually, there are 2 of these grooves in-line and the axis of both is Datum C. However, I zoomed in on my drawing and noticed that they created Datum A as a symmetry of 2 parallel planes at the centers of each torus.

Was thinking about creating 2 theoretical planes based on an alignment from each of the 2 toruses and creating a symmetry of each plane for Datum A. What do ya think?

Screenshot 2022-11-15 140714.jpgScreenshot 2022-11-15 141508.jpg

[[SH...]]

What kind of call out is this? what would be the datum feature simulator?? 🙄

[[Ch...]]

We measure these 'ball race' features quite often.

Ours specify a gage ball diameter to measure over.

We use this gage ball to "find" each race CL in Z, with self-centering and midpoint eval.
You can also measure 4 self-centering points to create a plane for each race/torus.

We also use this gage ball to scan for runout, but getting the D1 size with the gage ball is typically poor with scanning in our experience.

The D1 is typically a REF for us anyway, the size dimension over balls is the tight toelrance.

Our D2 is a basic Rad with a surface profile (Z is REF, so wherever the gage ball centers in the torus/race, etc)

Good luck !

[[To...]]

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HA Yes, some creative thinking required. This is an older drawing that is not using ASME standards.

[[To...]]

Has anyone ever seen this "red" condition bekore?

Screenshot 2022-11-15 152223.jpg

[[Ch...]]

Alignment is out of tolerance 🤣

Lol, no , not that I recall anyway.

[[Da...]]

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What are you talking about? It's just an aligmnent called "Upper Torus". So what?

About your problem, I would measure each torus with some single points, then measure the diameters at postion C (at actual coordinates of each torus) and use the axis of this two circles as datum.
For datum A just use symmetry point of both torus.

[[Ke...]]

Another option would be to measure the actual (D1) diameter of each torus, and recall those points into Planes, and then recall those into a Symmetry Plane... I don't think that there would be a significant difference between this method, and using theoretical planes based off of the Torus alignments.

[[To...]]

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Really? On the off chance that you might be colorblind, I've never seen alignments use any other color than black.

[[To...]]

UPDATE

The fine folks at the Zeiss Hotline determined the torus was the root of the problem. I can't tell you how many times I have said "torus does not play well with others". Apparently, red indicates there was something funky about using the torus in the secondary alignment.

So, we came up with measuring circles on the torus, then creating a plane and recalling the circles. I think this is a great alternative.

[[Ke...]]

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Interesting... I have used a torus for a secondary alignment many times, and never had an issue. I wonder what is "funky" about it.
Can you clarify on the method for your solution?

[[Cl...]]

Section the model like a pizza, 4-8 places, create 4-8 equally spaced 2d
curves. Scan them and recall each one's minimum point into a circle.

[[Ri...]]

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Alignments that use patterns in a feature will show up as red.

[[To...]]

UPDATE - Solution found

I got the same red letters when I used circles instead of the tori. The root of the problem was I was using a secondary alignment on the features that were in my Base Alignment. The light bulb went on when I caught a glimpse of the error window that pops up when you have a reciprocal dependency. Funny thing, I actually ignored that window because I thought it pop up with all of the changes I was making.

Anyway, I went with a simpler base alignment, then proceeded with my original tori and secondary alignments to build my ABD DRF. It gets the red out.

[[Da...]]

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Now I get it, I thought you marked it red by yourself 🤣