OD on this conical feature?

[[Br...]]

Hello all, I am having some issue getting an OD set up for the feature seen below. An auto circle on nom will not generate an actual, as you can see the difference between the two. My first inclination was to utilize a cylinder to capture max of both nom and actual, but I am having trouble figuring out how to go about that as well. I tried building a section, and associating a cylinder with the section, but the section will only accept a circle, not a cylinder, which makes sense, but doesn't make a solution 🙂 . I have attempted parameter change on fitting circle, "compute max distance" will not present as a editable option when I uncheck the box. I have also attempted utilizing a surface curve, but the stark difference in geometry is still an obstacle here. Any assist here would be appreciated.

[[Na...]]

Hi Bryan,

you could construct a curve by touch points (edge) and use this curve to create a fitting circle.

The approach with a cylinder would probably also work. You have to select the mesh with the feature, construct a fitting cylinder with this selection -> min. circumscribed for example. Due to the small height, you probably need to define a direction as a constraint for the cylinder.

Nanno

[[Br...]]

Hi Nanno, which measuring principal would you recommend? I have tried all available and cannot get the circle to lie on the correct position of the actual. Below is "project curve onto actual" which does not work. I can get the cylinder-built utilizing "copy as actual element", but no matter the distance added or constraint to proper axis, it will not adhere to the mesh as a proper cylinder.

 

Given that these geometries are so far off from CAD to Mesh, I went ahead and utilized a disc caliper at 0° and 90° to get diameter/ ovality, but would still like to solve this issue, as I was going for a GD&T check of roundness as well. 

Appreciate you time in response as always

[[Ti...]]

I can't see what is going on bc of the bad images you are posting.  How about some simple CAD model images of what you need?

 

The intersection of a cone and plane is an ellipse.  From what I see you need to construct an ellipse and use the cone and plane.  Then output the OD of said ellipse.

[[St...]]

Guten Morgen,

 

versuchen Sie es mal mit Silhouette. Das erzeugt eine Schnittlinie und in die können Sie dann einen Kreis fitten.

[[Na...]]

Hi Brian,

the edge curve can be assigned "no measuring principle", it's just a helping element. It is then used as the Curve in the construction dialog for the curve from touch points (edge). In my screenshot "Curve 1" would be your red edge curve from your screenshot. (There is also a measuring principle "Edges, Gap and Flush" but it might be a bit overkill for this application.

The silhouette proposed by

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 might also work with a correct selection.

Nanno

[[Br...]]

This is what I needed, thanks Nanno, thanks all!

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