Selecting geometry with radius

[scott]

I have been sent a few files without design history and they contain radiused surfaces - when I try and select the profile to allow milling of contour or 2D adaptive clearance Fusion doesn't like the 3D geometry that results as the profile dips downwards. I could extrude sharp corners and rebuild the surface to a 2D shape but it's time consuming. Am I missing a trick ?

This is a typical section - I would be milling this from above (Z axis) and doing the radius as a 2nd operation as well as drilling by turning the part (approaching from the Y axis) so a 3D ball nose strategy won't help and will not finish the underside surface. 

[seth.madore]

Without seeing your part along with the Setups and toolpaths, it's not entirely clear where the issue lies. Can you share it, either here or privately? Right click on the file in the Data Panel and select the "Share Public Link". Paste that link here, or you can email it to me at seth dot madore at autodesk dot com

[scott]

https://a360.co/3kCG6ZL

Here is the part - if it didn’t have the D shaped radius ends I would machine it as a 2D part - the geometry that is selected for contour is not the plan view silhouette as it wraps around vertically.

[engineguy]

@scott 

One crude but quick and easy "workaround" if all you want is the outline could be to split the body horizontally and then use the hold down "Alt" and select the shape, ain`t pretty  but it works, quick `n easy 🙂

Otherwise just use something like the 3D Adaptive, that will do it as well 🙂

Plenty of ways to do it, depends on how much work you want to put into it, above are just a couple of them 🙂

Stay Safe

Regards

Rob

[scott]

Thanks - tried this and needed to extend the tangents to allow the cutter to go past the cross-drilled holes - however it does a continuous tool path once I get to an extension of around 4mm but seems to then lift across the long edge and not cut the (previously) problem corners…

The 3D strategy seems to add steps to the arc.

Cheers

[engineguy]

@scott 

The Contour works fine here, maybe the settings and selections you are using ??

The 3D Adaptive will leave small steps but they will be machined off anyway later in your setup where you drill the holes and with a simple Contour for the Radi.

Files for both the Contour and Adaptive versions attached, go through the settings/selections and see if you can replicate on your model, image below is what I think you are trying to achieve 🙂 🙂 🙂

If you can`t get these to work then I am sure that Seth or someone else will be able to give you some better alternatives 🙂 🙂 🙂

Stay Safe

Regards

Rob

[seth.madore]

One method that's slightly cleaner would be to just create a Sketch on the top or bottom of the part and use Project. In times past, it used to fail to project the apex of the radius, but that's been vastly improved over time.

[engineguy]

@seth.madore 

Yep, that works, I didn`t even look at doing a sketch for the reasons you outlined, it never used to work properly so I have got used to not going down that road, I have found the slice horizontally is fast and easy so went down that road first is all 🙂 🙂 🙂

Stay Safe

Regards

Rob