CAD Forum

So,

When the genius' at my company wrote the PO for the design and construction of a piece of equipment that we will include in a larger system, they neglected to include fully functional solid models as a deliverable....

The vendor balked at the request of providing a full model, but did provide the assembly saved as a part, but with only the external surfaces.

While this is better than nothing, it's a fairly complex assy so there are a gazillion surface bodies.

Is there a fairly straightforward (and not enormously time consuming) way of turning this into a useful solid? I don't need, or want, all the detail of the stuff inside, just a solid made up of the outside surface. We will be adding brackets and stuff to the equipment, so I need to be able to put holes in the thing, etc. Can't do any of that with surfaces, well not easily.

thanks in advance,

bent

If the surfaces edges are connected you could run Knit Surface and just Ctrl+A to select everything.

But if its not just one solid you will need to run it and close them one by one. :/

It was probably @Alin that pointed me to "Silhouette".
Start a sketch on the Front plane and use Silhouette to get the external sketch of this assembly. Then do the same on the Right and Top planes. Once this is done, you can hide all the surface bodies in the Surface Body folder. Now you can create sketches and use convert entities to simplify the geometry. Once done, you can delete all the surface bodies and roll the freeze bar down and your rebuild time should go to pretty much zero.

I used the above method with a motor recently and it was much quicker than my previous method I was using.

There's also "Defeature" but I'm not as familiar as to how that tool works...But, it's made for this type of task.

See attached part.

Lucas wrote: ↑Fri Nov 05, 2021 8:23 am If the surfaces edges are connected you could run Knit Surface and just Ctrl+A to select everything.

But if its not just one solid you will need to run it and close them one by one. :/

Another technique that may work if it's a clean part/asm to grab all the surfaces to knit them together (click to show video):

mattpeneguy wrote: ↑Fri Nov 05, 2021 9:12 am Another technique that may work if it's a clean part/asm to grab all the surfaces to knit them together (click to show video):
grab surfaces.gif

Yep, if it is an assembly with many split solids this might come in handy

bentlybobcat wrote: ↑Fri Nov 05, 2021 7:31 am So,

When the genius' at my company wrote the PO for the design and construction of a piece of equipment that we will include in a larger system, they neglected to include fully functional solid models as a deliverable....

The vendor balked at the request of providing a full model, but did provide the assembly saved as a part, but with only the external surfaces.

While this is better than nothing, it's a fairly complex assy so there are a gazillion surface bodies.

Is there a fairly straightforward (and not enormously time consuming) way of turning this into a useful solid? I don't need, or want, all the detail of the stuff inside, just a solid made up of the outside surface. We will be adding brackets and stuff to the equipment, so I need to be able to put holes in the thing, etc. Can't do any of that with surfaces, well not easily.

thanks in advance,

bent

I'd suggest focusing on the surfaces where your brackets will be applied. Extract (copy offset 0 or saveas a parasolid, selected surfaces) only those regions for now so you can get your work done now. Later see if you can patch the import up. Can you post or share the file with someone here? (I can take a look and will sign a NDA if needed). I'm sure we can give you a honest answer of "if" it's worth attempting to repair/fix or how much time it may take to fix or just leave it as is for (that is, this is what the client gave us as a reference)? Good Luck!

Whenever I receive assemblies saved as part with external surfaces only, it is always a complete mess of perforated surfaces and hundreds of import errors. My requirements are to show it unmodified, fabricate things around it, and represent mass for total and center of gravity. I normally do not fill the many many gaps in the surfaces, nor ever attempt to knit them into a solid. I think that I did try to in the 1st time I encountered this. I usually place a rough solid body within the surfaces for the purpose of carrying through an overwritten mass into the assembly.

Sometimes I will generate my own bodies to replace portions of the surfaces entirely, or swap out similar bodies from the same product series where the manufacturer produced solid models. Maybe if a huge face is missing that would be blatantly obvious in its assembly drawings, then I will mock up a replacement. I've had the case before where its entire foot surface was missing, but I'm not showing that view, so I generated a reference plane and bolt down axes and proceeded.

There is ONE easy way, and you have already tried it: ask its producer for better source materials that are not all messed up.

What you ask for could possibly be done, or approximated. I bet that the correct answer that no one else wants to tell you is: No. There is no easy way to repair a gazillion gaps.

Your case could be almost anything, with opportunity for complexity. Your "piece of equipment" that is "a fairly complex assy" is not a box or a cylinder or other discrete geometry. Without knowing what you've got or what you're dong with it, I recommend moving on with adapted junk if unable to request better source material. You will not be able to simulate it. You will likely not be able to make plastic molds from it. You will not be able to generate a section view through a surface body (maybe this one has been fixed in newer releases, but I haven't heard so). You can make holes in surfaces, and place reference entities for ease of mating upon some broken geometry. They come through acceptably in 3D PDF's also, even if it may require multiple render attempts.

If I am buying a product and not fabricating it, then I use representative junk as-is and adapt it to my workflow. Perfection only exists in an ideal world or with limitless effort.
This topic is deja vu.

There are two other ways around it. You could create a solid containing all the surfaces and use Split or Intersect to separate the solids inside them.

It might be super slow (especially for the Intersect)

And for the gaps you could use Extend Surface or Untrim Surface to make them intersect. But if you have a gazillion gaps you will have to repeat it a gazillion times

Lucas wrote: ↑Fri Nov 05, 2021 8:10 pm And for the gaps you could use Extend Surface or Untrim Surface to make them intersect. But if you have a gazillion gaps you will have to repeat it a gazillion times

image.png

Or you could use Knit Surface and set the gap to something reasonable that would capture all the gaps...say 3 feet?...

mattpeneguy wrote: ↑Mon Nov 08, 2021 9:54 am Or you could use Knit Surface and set the gap to something reasonable that would capture all the gaps...say 3 feet?...

That would - no ironically - be awesome. lol
Or if the Knit Surface could auto-trim past the closed volume too, but that's too much to ask, right?

A Unknit feature would also be nice, but I think they are not into that kind of stuff; people might start asking to change the name to SurfaceWorks ¯\_(ツ)_/¯

What you really need to do is repair the relationship with the vendor. See what you can do to get directly in touch with the people who can do the most.

This may take patience and persistence. Companies are loathe to connect their engineers directly with each other. Mostly because there are people who feel the need to justify their value by controlling information flow.

It may take hours or days, but once you're connected to the right person, the problem will be solved in minutes.

The Human Element of Electromechanical Collaboration
https://www.engineering.com/story/the-h ... laboration

Engineers don't get to talk to each other across vendor lines... It's the hardest wall to break. It's the best wall to break.

Finally somebody gives up and lets the engineers talk to each other... That's when it's almost magical, and the other guy says, oh, all we have to do is this and we're good to go. That's all it took. It took two weeks of wrestling to get me to talk to this engineer, and it took him two minutes of consideration and going 'oh yeah all we’ve got to do is this'. That's a scene that's been repeated many, many times.

Wow! Lot's of good responses.

Sorry, was off doing something else and forgot about this thread.

Agreed, the easiest solution is to get a real model. Unfortunately they want a lot of $ for that and management doesn't see the value.... My time is seen as "free".... grumble.

Sorry not able to share models. We're inside a "protected enclave"....

I'll try some of the other ideas and report back.

Thanks for the great ideas!

bent

HerrTick wrote: ↑Tue Nov 09, 2021 9:13 am What you really need to do is repair the relationship with the vendor. See what you can do to get directly in touch with the people who can do the most.

This may take patience and persistence. Companies are loathe to connect their engineers directly with each other. Mostly because there are people who feel the need to justify their value by controlling information flow.

It may take hours or days, but once you're connected to the right person, the problem will be solved in minutes.

The Human Element of Electromechanical Collaboration
https://www.engineering.com/story/the-h ... laboration

Apparently that author never dealt with Caterpillar Inc.

Well, the model FINALLY arrived. Geeze. 14,124 surface bodies.

As suggested, above I'm going to remodel a very limited subset of the interface areas as necessary and call this done.

I could spend the rest of my life on this.....

Thanks all who chimed in.

So,

We kicked this back to the procurement team and asked for a real model.

Let's see what we get.

Maybe a Christmas present!

Please Santa?

LOL!

While helping a client in a similar situation, I was quite successful using a combination of defeature and convert to sheet metal to get what he needed in a reasonable time. Convert to sheet metal is fantastic for surfaces (if you have sheet metal parts, of course).