topic Re: Chamfer problem, weird edges fix? in Fusion Design, Validate & Document Forum

Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 11:35:07 GMT

Hi there,

I'm trying to fix these edges.

Getting strange angles on them.

I've sketched out the shape then cut it out of the object.

any ideas?

(gif file)

https://imgur.com/a/UZcC6hR

Thanks for helping (scene file included)

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 12:43:47 GMT

That's wild, warrants examination- File > Export > and attach the F3D to your post here.

Re: Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 12:47:29 GMT

Sure thing here is the file.

Re: Chamfer problem, weird edges fix?

TheCADWhisperer — Fri, 05 Oct 2018 13:18:53 GMT

I stepped through you model from beginning to end and your technique does not look logical to me.

Have you tried parametric modeling instead of the technique that you used?

What exactly are you attempting to model - I am sure there is a easier technique.

Re: Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 13:35:22 GMT

Hey thanks for the quick response.

Trying to figure out how to make something similar to this.

Re: Chamfer problem, weird edges fix?

TheCADWhisperer — Fri, 05 Oct 2018 13:54:14 GMT

That looks like an ambitious project for a beginner.

Are you attempting to model a single part or are you attempting to model an assembly of parts?

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 14:01:13 GMT

I deleted all the extraneous intervening Features in the Timeline- of course, the Chamfer irregularity persisted. Thinking it might relate to the use of Primitives, I rebuilt the Cylinder as an Extrusion from a Sketch; however, the result is the same. Isolating each Edge, I progressively applied the Chamfer to one Edge at a time-

The problem is that bottom, inside Edge- the Chamfer is 1) a bit too big to be applied given the depth of one Face and 2) Fusion is using it's best reckoning for what angle to apply the Chamfer to those shallow-angled Faces, which contest with adjacent Faces for priority.

Is this a bug? At first glance, I'd expect the Chamfer to deliver a uniform edge- but is that realistic?

Re: Chamfer problem, weird edges fix?

dmorse — Fri, 05 Oct 2018 14:01:32 GMT

I agree with @TheCADWhisperer. There are some modeling techniques that need to be addressed, because they will cause you issues down the road. That aside, the chamfer distances needed to achieve the desired outcome are not equal, due to the angles and curvature. I would recommend creating separate chamfers, starting with the larger, equal segments, then following with subsequent chamfers where you'll need to tweak them in order to achieve the smooth transition. See my image attached. There are some resulting anomaly faces, but this is probably due to the previous modeling techniques. Hope this helps.

Re: Chamfer problem, weird edges fix?

michallach81 — Fri, 05 Oct 2018 14:06:01 GMT

The part from picture have fillets done before chamfer.

Re: Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 14:44:41 GMT

Thanks for this.

What if I didn't want the fillet like how I was trying to let that work?

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 14:51:03 GMT

Michał's solution allows for a tangent Edge chain. It's worth noting the Chamfer produced is limited by and dependent on the size of the Fillet, and the Chamfer width is not uniform along the chain.

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 16:23:58 GMT

That got me thinking about how the Chamfer is produced. We can see just about the same narrowing were we to Pipe Cut the Path:

Essentially, a Circle Profile has been Swept along the Path. Self evident, the depth of Cut must vary in order for the Face width to stay the same; lacking variation in depth, Fillets help smooth those transitions, with limited blending of the Face widths. So, what to do? I considered a bunch of overly elaborate operations involving Planes Along Path, Projections, a bunch of Sketches- all of which I dispensed with by using Fusion's main strength- solid modelling. In the following illustration, I Chamfered all the lower Edges individually, then performed a Press Pull operation on individual Surfaces to bring their Edges into conformity, zooming in and using the digital control to adjust.

Now THAT is what I expected from selecting all the Edges for Chamfering at once- but, through process, it's easy to understand why the tool performed otherwise. It would be cool if Chamfer featured a Conforming Edge selection option, eliminating the need to eyeball the Press Pull operation.

Re: Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 16:21:37 GMT

intresting, thanks for exploring this.

Any way for you to record the process. Not fully with you here.

Cheers!

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 16:51:09 GMT

Here you go. This also demonstrates Press Pull is an entirely different critter than Extrude- which I all-too-often reach for when I actually want to perform a Press Pull!

Re: Chamfer problem, weird edges fix?

Anonymous — Fri, 05 Oct 2018 16:54:57 GMT

Thanks for this!

Re: Chamfer problem, weird edges fix?

mavigogun — Fri, 05 Oct 2018 22:31:08 GMT

@Anonymous wrote:
Thanks for this!

Happy to. Just pay it forward.