CAM 2D contour: Manual tab placement doesn't work on some contours

[silvan.linnZW8KL]

In the CAM/manufacture workspace, certain contours are not selectable for manual ("at points") tab placement. The difference between contours that work and contours that won't is not clear. I've attached a file with two parts in it and two machining operations. In one, I have used automatic tab placement ("by distance") to put tabs on the part, and it correctly places them along the entire contour. In the other I have used manual tab placement, and I can select any point along the outside of the arc, but there's something different about the inside contour and the software won't let me place tabs there.

I suspect that this might be related to the degree of the curve or the method by which it was generated. The outer contour is a segment of an arc with degree = 2, but the inner one is a trimmed offset surface with degree = 3. I don't know how to show this in Fusion so I exploded the file in Rhino and attached an image below 😛

It would be great if you could take a look at this bug, as manual tab placement is extremely useful for parts with complex freeform shapes where this issue is likely to appear.

File: https://a360.co/3lTepfy

[seth.madore]

That a very good question. I've reached out to one of the developers for a bit of perspective on this and will reply back when I've dug a little deeper.

Moving this to the CAM forum.

[seth.madore]

So I checked in with one of the devs who would know most about this. He confirmed that "Selected Points" does not work on spline curves, which this is. The work needed to implement this is actually quite large and not likely to be undertaken. HOWEVER! I did find a good little work around: create a sketch on the base of the part, project the spline curve to the sketch and then use "Point" and add points to where you want the tabs to be. You can then select those points in your tab selections:

 

[silvan.linnZW8KL]

Good to know that I was on the right track with my suspicions 😛

Well, I won't argue the amount of coding work the feature might require as I'm not the expert there (though, like, if you can add points on a converted sketch line with identical geometry...) but I will reiterate that it would be a super useful feature. We do a lot of machining of freeform plywood parts from all sorts of sources (generated directly in Fusion, imported from Rhino, SolidWorks, Illustrator...) and manually placing tabs is always useful.

Good to know there is a solution involving the projections/points though. That at least will help as a workaround.

[seth.madore]

I'll point out that I think this is the second time in 6 years someone has needed to put a tab on a spline curve. Either all users have figured out the workaround, or the demand for it is very low. 😉

[jandyman]

I ran into this same issue today, just FYI. I'll use the workaround for the time being.

[seth.madore]

We have fixed this internally, so it's a matter of time before it moves into Production version of Fusion.

[jandyman]

That is most excellent!