Chamfer on already existing chamfer

AntonGrant
Explorer
Explorer

Chamfer on already existing chamfer

AntonGrant
Explorer
Explorer

Chamfer on already existing chamfer makes strange result. If I create on top and bottom faces of cube one chamfer, and on top of that chamfer feature I make another chamfer feature with exactly same distance, then new one makes result with more distance than needed.
Example, like I said cube with first chamfer Fusion360_sDtlJ5UR1n.png
Then creating second chamfer feature
Fusion360_Y3FBk4HX9E.png
Makes this
Fusion360_beRP7Ubhuw.png
Fusion360_XOMuN9VLRW.png
I can't understand why it's different from 0.1cm , when i specifically told make 0.1cm chamfer 

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TheCADWhisperer
Consultant
Consultant

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

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AntonGrant
Explorer
Explorer

Here you go

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TheCADWhisperer
Consultant
Consultant

I am having trouble visualizing what you are attempting to model.

Do you have a picture of something similar that already exists in the real world?

TheCADWhisperer_0-1667131533439.png

 

Tip: Rather than use Chamfer - sketch in the beginning/end points of where  you expect the geometry to cut.

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AntonGrant
Explorer
Explorer

It's just a quick example with the cube. I just need chamfer like this one

blender_w39os8EDqH.png

I mean, this strange behavior in fusion happens everywhere in similar situations. Even with real world examples.

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TheCADWhisperer
Consultant
Consultant

Uhmm, this distance is the hypotenuse

TheCADWhisperer_0-1667132202429.png

 

TheCADWhisperer_0-1667132413032.png

Perhaps if you Sweep with an equilateral triangle

or 

Pipe instead.

 

TheCADWhisperer_1-1667132472614.png

 

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AntonGrant
Explorer
Explorer
Yeah, i know that. But don't you see difference between my last picture on original post and your sketch or even my example made in blender?
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AntonGrant
Explorer
Explorer
Wait. This just overextend amount of work. Isn't Chamfer feature is actually what should work in this situation?
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TheCADWhisperer
Consultant
Consultant

@AntonGrant wrote:

Even with real world examples.


Can you Attach image to real world example?

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AntonGrant
Explorer
Explorer

@TheCADWhisperer wrote:

@AntonGrant wrote:

Even with real world examples.


Can you Attach image to real world example?


I don't have one

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TheCADWhisperer
Consultant
Consultant

@AntonGrant wrote:
I don't have one

That brings us back to the request to map points.

Create geometry and add beginning/end points to where you really want to cut.

Then we can figure out the most efficient technique.

If you have to use some other software (Blender?) than do that and Attach your geometry here.

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AntonGrant
Explorer
Explorer

I still can't understand why fusion makes a chamfer different from the one I specified. Like makes 0.122cm chamfer, when I specified 0.1cm. Even when I choose only one edge. Where did this 0.1cm go?
Fusion360_bSXpvgYgm7.png

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TheCADWhisperer
Consultant
Consultant

The triangle you are measuring is not perpendicular to the edge that you selected.

TheCADWhisperer_0-1667137214973.png

 

I'll try one last time...

Q. Can you plot out the desired start/end points and Attach the file here?

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AntonGrant
Explorer
Explorer

@TheCADWhisperer wrote:

The triangle you are measuring is not perpendicular to the edge that you selected.

TheCADWhisperer_0-1667137214973.png

 

I'll try one last time...

Q. Can you plot out the desired start/end points and Attach the file here?


I just don't quite understand what you want to me to do. Something like this?

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wmhazzard
Advisor
Advisor

You are measuring from the wrong location. Measure from where the corner of the cube was, IE .25 inch. 

 

Screenshot 2022-10-30 105727.jpg

 

If you select all corners first, you have corner options in the chamfer dialog box. 

 

Screenshot 2022-10-30 110114.jpgScreenshot 2022-10-30 110027.jpgScreenshot 2022-10-30 105954.jpg

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AntonGrant
Explorer
Explorer

@wmhazzard wrote:

You are measuring from the wrong location. Measure from where the corner of the cube was, IE .25 inch. 

 

Screenshot 2022-10-30 105727.jpg

 

If you select all corners first, you have corner options in the chamfer dialog box. 

 

Screenshot 2022-10-30 110114.jpgScreenshot 2022-10-30 110027.jpgScreenshot 2022-10-30 105954.jpg


But the thing is corner of this edge was where I actually measure. It's 2 different chamfer features. And if I use only one, I don't get desired result which i show you in my blender screen.

blender_w39os8EDqH.png

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laughingcreek
Mentor
Mentor

let's back up and get a baseline of what should be happening with the chamfer and where we need to measure from. the equa distant chamfer measures back from the edge selected-

laughingcreek_0-1667146217340.png

so when you put a chamfer on this edge-

laughingcreek_1-1667146311380.png

it measures back from the EDGE-

laughingcreek_2-1667146420978.png

you can see the chamfer is being applied correctly.

 

manipulating a mesh in blender works differently, because it operates on the vertices directly.  but the result aren't always what you might think.  I converted your mesh to a berep and took the same measurements as above and here are the results-

laughingcreek_3-1667146673846.png

 

 

you can get closer to what you want by reversing the order that the chamfer is applied to the edges-

laughingcreek_4-1667146877467.png

and if your trying to get that trapezoid face to be rectangular I suppose you could fudge it with the move face command to get it close, but that seems a bit janky to me-

laughingcreek_5-1667147164855.png

 

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wmhazzard
Advisor
Advisor

Blender is not a CAD program, it makes nice pictures. You can make a corner like that if you construct an axis through the bottom two points and then a plane at angle along the axis, then split body with the plane. You will have to do math though to get the top and bottom edges equal length, it is around 36 degrees, not 45. 

 

Screenshot 2022-10-30 125141.jpg

Screenshot 2022-10-30 124647.jpg

 

 

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KristianLaholm
Advocate
Advocate
Accepted solution

If the intent is to have the same chamfer on all edges and the "miter" to be rectangular face then:

  • Chamfer 2 opposite faces (8 edges) with dimension = 0,1cm
  • Chamfer 8 new edges created by previous chamfer with dimension = 0,1cm * sqrt(2) / sqrt(3)
  • Chamfer reminding 4 edges with dimension = 0,1cm

(Used a user parameter in my file)

Skärmbild 2022-10-30 174310.jpg

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