Weekly Challenge Group

Just kind eyeballing dimensions but reasonably close. I am curious to see it posted in one feature though.

Sorry, the idea is that you open my linked model (STEP, Solidworks, or x_b-format) and remove the cutout from the sphere in one feature.

Is the challenge to use the "trick" to exactly remove/fill only the cut out?(which I believe is what you are going for).

Else, a simple overlap revolve in SW can still achieve this.

Yes, the trick is very fast and easy and relatively unknown. If you want to do a revolve, you need planes and sketches and this is 2-3-4 extra steps.

Yes. I did the revolve in 3 steps. Needs a plane for the centred sketch because the sphere is offset from the origin. I don't know the trick as of now but will wait until others have tried out. Interesting. Thanks.

Edit: I could fill the empty space with boundary boss but could not merge the bodies. I think the trick is around here.

Hello Steen!

Your proposal made me curious.

My intuition led me to create an extrusion, angled, up to the surface...

I don't think this is the trick... but it's what I could do!

Impressive that you was able to make this work! The trick derives from surface modelling - it is a two step operation that is available in Solidworks as one feature. Not sure if other CAD modellers need one or two features...? I will reveal all when more people have had a chance to solve it.

The trick derives from surface modelling - it is a two step operation that is available in Solidworks as one feature. No need for planes, sketches, etc.

Yes.

This feature is a part of Fusion 360 as well.

Gotcha. Misread what you were after. :)

Inventor. Only takes seconds when you know the command.

No sketches, workplanes etc. Just one single command.

This process is most useful when working with imported dumb solids without an editable feature tree.

Steen, chico travieso, espero que el truco no sea simplemente "borrar y emparchar"... (funciona bien)

What is wrong with "borrar y emparchar"? It is a beautiful surface operation, that works when the surface(s) involved are free of errors :-)

It is truly a single command and not a group of commands under a single feature.

It does kind of look like a smiley face.

It is one command, but it performs (at least) two operations.

Very simple if you know this function. SW, 1 feature

This command removes a face and extends all neighboring faces to a mutual intersection.

In Inventor there is no indication of multiple operations. It's one command and done with no options. No surfacing involved.

[edit] There are occasions where can do multiple operations under this feature but to accomplish this particular task is just a single operation.

Not true. It is all done behing the scenes...! I want to explain what s happening, but I won't do it before the end of the week ;-)

...the end of the week is too far!

This is not doing my anxiety any good... I'll have to start smoking, drinking or something!

For those of you wanting to know more

(here is looking at you https://grabcad.com/capricornio-1 )

I have made a tutorial based on what I was introduced to by Solidworks guru Mike Puckett at a Solidworks User Group in Sydney in 2013:

https://grabcad.com/tutorials/how-cad-handles-solid-geometry

Thank you very much Steen!

I think this is the ideal way to "close challenges and questions".

Not only with one or more possible solutions, but with some reflections and additional data that increase our knowledge, taking advantage of "the impulse" that curiosity provides to solve something.

This is not easy to achieve in the classical classroom where "knowledge is imparted before the person really needs it." Understanding is achieved but the ideas do not necessarily become their own. On the other hand, when the need manifests itself first, the motivation to learn is much greater and its memorization is much more efficient.

Again, thank you very much for this knowledge!

Late to the party but did it in one feature. Maybe there is more than one solution? I feel like the tool I used was too easy.

Step 7 in the tutorial will tell you what is going on 'behind the scene' when you use the 'Delete face and patch'-tool.

https://grabcad.com/tutorials/how-cad-handles-solid-geometry

Incredible work, sir. I always tell new learners in SW to focus on surfacing more because solid modelling in SW is just surfacing in the background. ;P

Thank you :-)

and yes, indeed, solid models are just 'good' surface models when you look closely. The 'solid'-tools are quicker ways to achieve the same result, and the 'surface'-tools can achieve results that would be slower and/or more difficult with 'solid'-tools.

The trick is to use "delete Face" command of surface modeling, by selecting the option of 'delete and patch'.

The down side is I’ve seen some people attempt surfacing on a solid model for no good reason. Combined with not knowing what they were doing, completely and irreversibly destroyed an otherwise good solid model. One example was a very complex model of an F-1 race car. They had switched back and forth between solids and surfaces throughout the history of the model. It looked incredible, but it was so convoluted and broken, the only way to fix it was to start over. The whole thing could have been done easily and completely using pure solid modeling only.

In the 30 years I’ve done design work using a solid modeler of one sort or another, only one single time was surfacing considered to accomplish a task. It was to produce a cosmetic surface resembling a blob of epoxy on an oddly shaped surface. (It’s actually on one of my models posted on GrabCAD.) I don’t know of any other instances, for myself or anyone else, where surfaces could have done a task better. (Granted, I’m designing machinery and not figurines.) Such is the case with the model in question here. A single step process using solid modeling tools. Or a multi step process using surfacing. The end result is the same. Yet solid modeling is much easier.

Unless you’re working on organic shapes like car bodies, I submit that it is rare that surfacing tools should even be considered.

There are more than one method to do the things in solid works. I consider this as 'Capricornio' achieve this with extrude command in above posts.

I'm always interested in alternatives! what solution did you use?