Creating ribs to match complex shape?

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TWrecks
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Joined: Sun May 28, 2017 6:54 pm

Creating ribs to match complex shape?

Post by TWrecks »

At times I want to create structures like ribs along a complex shape typically generated from a solid using the "Thickness" tool. The PAD tool doesn't support padding to a non-planar face. Currently I am working with the PartDesign workbench, but in the past I have use Part workbench to do a Boolean AND operation with the rough rib and original solid to trim the rib to match the shape. This doesn't seem readily possible in the PartDesign workbench.

What is the recommended way of doing this?

Thanks!

Tim

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chrisb
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Re: Creating ribs to match complex shape?

Post by chrisb »

You can either sketch the ribs from the side or use the type to-first if you want to pad to a non linear face.
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TWrecks
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Re: Creating ribs to match complex shape?

Post by TWrecks »

The "to first" method doesn't work as it stops as soon as any part of the rib touches the face. Likewise "to last" goes to far.

The side-pad method kind of works, but the hard part of that is matching the rib contour to contour of the face. In the case shown here, the face is is curving in multiple planes. I wasn't able to select a refence edge edge for the rib sketch either, I had to just fudge it. Then when padding it very far, as the contour changes the rib pad begins to detach from or protrude through the face.

One method I played with was to use Part WB "Section" tool to trace in 2D the contour where it is to meet the rib. Then Draft WB to convert Draft to Sketch, and use that as a starting point for the rib side pad, but still has issues similar to above if padded very far.

The Boolean AND seemed the best workaround but I can't get it work in the PartDesign WB.

Tim
freedman
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Re: Creating ribs to match complex shape?

Post by freedman »

It will pad using "up to face". It might take selecting a couple times, you can see that I made the boss and padded down to the complex face. You need to select the face to pad to.
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TWrecks
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Re: Creating ribs to match complex shape?

Post by TWrecks »

Pad "up to face" works until I extended the rib beyond the smooth contour in the middle into the areas as shown in red, then it gives "resulting shape is empty". It only lets me select one face, but there are 3 involved.

The side pad method is kludgey but I did get what more or less what I wanted.

Thanks!

Tim
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freedman
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Re: Creating ribs to match complex shape?

Post by freedman »

Ya, I kind of thought you were merging into the sides. I use sketcher with model transparency set to a see-thru, then I can see into the solid to adjust the sketch elements. This is pretty much my work flow all the time.

In case you want to try, I have written a macro the sets global transparency, it really helps in Sketcher, 100 is the standard solid. I set to 50 or 5 while in Sketcher and 100 in normal model mode, but it can also be useful to see thru the model (for fit) outside of Sketcher.
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chrisb
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Re: Creating ribs to match complex shape?

Post by chrisb »

"To last" should work:
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I may add, that To forst and To last are stable with respect to the topological naming, while Up to face is not.
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Cekuhnen
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Re: Creating ribs to match complex shape?

Post by Cekuhnen »

Chrisb

Does FC have directly model like abilities

Aka

Break the rib task into two steps

Pad it onto a compatible surface and then grow it left and right into the walls ?
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TWrecks
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Re: Creating ribs to match complex shape?

Post by TWrecks »

chrisb wrote: Tue Jul 27, 2021 6:10 am "To last" should work
It also gave me a "shape is empty" error when the pad crossed those lines. The line that makes boundary is a b-spline, that may be part of the issue.

I still like the method of AND'ing the rib with the original solid (before the thickness step) but I'm not sure how to do that in the PartDesign WB.

Tim
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Shalmeneser
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Re: Creating ribs to match complex shape?

Post by Shalmeneser »

TWrecks wrote: Tue Jul 27, 2021 2:33 am The side-pad method kind of works, but the hard part of that is matching the rib contour to contour of the face.
contour of the interior face or exterior face ?

File ?
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