Measuring Wall Thickness on Cone Angle

[[Ad...]]

Hey Guys,

How would I measure the thickness of a Cone Angle? I have tried a couple of methods but I am not confident if I am getting right results. The feature is 'D'

D Feature 2.pngD Feature 1.png

[[Ma...]]

I don't think there is any easy solution.

You can create cuts -> 2d lines -> simple distance or using rotated alignment with caliper distance.
You can use curves. You can recall some points into 2d lines.

[[Da...]]

its not look easy
its a short ring with larger diameter ?
if i'm not wrong i would put it on something flat and use profile in few places around it, and see if it gives stable results.

[[Ma...]]

I think you would be far better off using a snap gage or similar instrument with spherical contact points than than you would be trying to measure this on a CMM.

[[Ri...]]

Please sign in to view this quote.

I would agree with this - especially given the tolerance.

If you just have to have the measurement on a CMM - I would attempt the suggestion above of using the Caliper Distance with a rotated coordinate system. It is possible to maybe use the Curve Distance function.

Measuring this on a CMM will require testing and correlation.

[[To...]]

The following would be similar to snap gage discussed earlier.

If you're working from a model, you can choose Distance Check in the CAD selection tool. Click on the model and it will put a Space point where you clicked and then another Space Point on the opposite side. It then creates a 3d Distance between both points. You will likely need to change stylus and clearance planes for each point.

Without a model, take a point on the surface. Change the evaluation to a Plane point. Click "Measure Normal Vector Now" to figure out the vectors. I usually do this a couple of times just to refine the values. Then, set "Measure Normal Vector Always". Then, I copy and paste the point and reverse the vectors so they're opposite but inline with original point. (again, you will likely need to change stylus and clearance planes). I also increase the "Search Distance Before Nominal Position" under Probing section in Features Setting editor to allow for part thickness. Assign both points to a 3d Distance. You will need to enter the nominal distance because both points have same nominal location. I haven't done this in a while so I'm not sure if I haven't missed a step.

Of course, repeat for as many places as needed. Arrange points by stylus to minimize back and forth motion.

[[Ma...]]

This looks like an oil seal spring for sealing a round face. The real difficulty measuring this on the CMM is the flexibility of a part that's only .006-.010 inch thick. Without an opposing force to counter the deflection under normal probing pressure your thickness measurements may appear much smaller than they actually are -perhaps even negative thickness.

[[To...]]

Please sign in to view this quote.

Got it. Might be a good time to activate "Elastic parts" option? Assuming an active sensor...

[[Ro...]]

I had a similar problem earlier this year.
My final solution was to create a line on 1 surface and a point on the other side.
Adjust nominals so they were exactly on the opposite from each other and construct a perpendicular feature and the "depth" will be your wall thickness.

[[Ma...]]

Please sign in to view this quote.

With 2d line and point should be enough to use simple distance or cartesian - since point to line will always be perpendicular

[[Je...]]

Instead of creating a 2d line and a point. The advanced method would be to scan both cones using multiple line scan paths in your strategy. This allows the measurement of the cone for your standard dimensional reporting and creating of a feature to use for wall thickness without adding any additional measurement cycle time. If you do not need to measure the cone for any other purpose, creating and using a section through CAD > Creating Features would be the most appropriate.

Rather than creating a 2d line on the cone and trying to adjust nominals, For the 2d line, use Recall Feature Points, left click on one of the cones, right click > open. Select an indvidual path. (many users are unaware that you can select the individual paths of features from recall feature points options. Such as individual circles from a cylinder feature)

Do this for both cones. If you set your start angle and rotation angle to the same values from your features then your paths are directly opposite walls from each other. You can now create a point from the 2d line and evaluate perpendicular distance from your newly created recall features.

You can do this for individual circle scans on cones as well to check X/Y locations of ID/OD rather than using cone vertex for locations that can often have projection error due to geometry constraints.

[[Ri...]]

FYI - you get a pretty graph if you use the Curve Distance tool. 😃

[[Ad...]]

Thanks everyone this is good measuring information. I did forget to mention that I do not have PCM, Curve, or a model.

[[Ri...]]

I use alignments.
Create an alignment to the surface. then probe the other side of the surface.
You get real time results this way.