I have a zigzagged plate that has been deformed into a concave shape using the Flow command. I'm trying to create a solid object in the space between the red and blue curves underneath it. However, when I attempt to extrude or loft, it doesn't cap the object. Why don't extrude and loft functions work in this case?



I found a way to obtain a solid using the Sweep command, selecting "Pointy end" for the Ends option, which results in a solid object. However, when I try to join this solid with the zigzagged plate using Boolean Union, it fails.

What methods do you use to achieve such shapes?



marzRX

1/ Delete the bottom of zigzag solid
2/ Select all the bottom edges of the zigzag polysurface
3/ Join them to have a first path
4/ Draw a line with two points of a corner
5/ Sweep this line with 2 paths (bottom curve and the path made in (3)
6/ Do a plane with the bottom curve
7/ Join all surfaces to have a solid

Phiro, thank you.

I've tried the method you suggested. Are the "two points of a corner" you mentioned in the fourth step referring to the location shown in the attached image? When I select that area, the bottom doesn't seem to flatten, so I can't use the plane command. Am I doing something wrong?



I'll try some more.

marzRX

OK ! OUPS !

Sorry I thought you want have a flat bottom part using the blue shape.

Well using my method, you could next "cut" (boolean dif) your solid with a curve copied from the edges of your zigzag initial solid.
A solid cutted by a curve (by boolean diff) could stay a solid.

Thank you, but I still haven't obtained a solid.

> Sorry I thought you want to have a flat bottom part using the blue shape.
Yes, the solid I want is one with a flat bottom. This part will be placed on top of another flat part.

> A solid cut by a curve (by boolean diff) could stay a solid.
The shape I obtained after sweeping was not a solid, but a joined surface. Am I still doing something wrong?



P.S. I want the bottom surface to be flat, so it can be closed with a "plane".
However, the top surface remains open after sweeping, which seems to prevent me from getting a solid.

Well, it's late today, so I'll continue this tomorrow.

marzRX

“”””” > A solid cut by a curve (by boolean diff) could stay a solid.
The shape I obtained after sweeping was not a solid, but a joined surface. Am I still doing something wrong?”””””

Yes, phiros post above is the method to use

Extrude your blue profile up past the zig zag (a solid rectangle you have)

Now using curve of zig zag (still have the curve? Or extract it from current zig zag surface)

Boolean diff zig zag from blue block. Delete top part.

Oops

I see zig zag part has an angle in its direction. So extraude “its base curve” down past plane of blue profile (be sure extrusion is an open surface

Trim this extruded surface with a planar line and delete excess. Join all and planar command.

Hi, BurrMan. Is your method different from the approach Phiro suggested? Does "its base curve" refer to the red profile?

Upon re-reading Phiro's method, I think I might have misunderstood something.
> 1/ Delete the bottom of the zigzag solid
This means to delete the bottom face of the zigzag solid, right?
I misunderstood and removed the blue and red profiles and black vertical lines instead of the bottom.

Phiro, Are you instructing me to delete the bottom face of the zigzag solid and then select the blue and red profiles, and also select the two vertical rails that connect them, to perform the sweep like shown in the attached image?



I think I am going in the right direction with this method.
However, after joining the three surfaces with the join command,
I got not Solid, Joind surface.

marzRX

Hi marzRX.
I do not know if I understand you correctly, but look at these ways.



https://disk.yandex.ru/i/_Xy7GcDrVYUaYw

WN, Thank you so much for providing me with four different ways to do this.

I was able to obtain a solid using each method after watching the video.
It was a demonstration on a model that I could actually access, so it was more informative than any YouTube video!

I understand that Phiro's method is the second method, and BurrMan's method is the third method.

My mistake was to stubbornly try to create a solid under the zigzag solid. Only the fourth way is such an approach.
I also made the mistake of using "Edit | Join" to join each surface to get a solid.
I learned that the correct way was to use "Boolean | Join" as shown in the video.

I've been using MoI for about two years now (= my CAD experience). Dismantling the bottom of a solid to make it a joined surface and then adding other faces to create a new solid was a fresh approach for me.

I usually make simple models or models using Revolve, and I'm currently studying to make a cutter as part of my skill improvement.
This part is the grip of the cutter.

Thank you, Phiro and BurrMan. I was able to understand thanks to WN's video. :)


marzRX

Sorry, had not posted the video yet

"""""""Hi, BurrMan. Is your method different from the approach Phiro suggested? Does "its base curve" refer to the red profile?"""""""

Yes. I finally got a chance to download your file and found a small anomoly in one of the original surfacves, so I made a quick vid of me fixing it, but I didnt get into depth. Just showing a quick fix when a solid had "Naked Edges"

The area at the "red profile" on your zig surface had a couple little sliver surfaces that prevented it from becoming a solid (You see it in the video)

As a quick fix I just deleted all those planar surfaces and ran Planar which replaced everything. If you started by running "sperate" and just deleting single surfaces, you will see the little sliver.

Anyway, just for you to view what I did to your model to generate the bottom half you were looking for...

Phiro, I see that I can create solids without "Boolean | Union" by using "Edit | Join"!
In Loft and Extrude, I had to join with "Boolean | Union", so is it possible to say that the surfaces are more well-formed, or "well behaved", compared to those?

BurrMan, Thank you. I had always wondered why some solids require a Union and others can be done with a Join.
This video has melted that question away.
The command used at 0:17 and 1:03 is "Highlight Naked Edges", correct?
If I want to get a solid and I get a Joind surface, I will actively use this command to investigate.

marzRX

Hi MarzRX,
Yes, naked edges. I have it shortcuted so you didnt see me type it. Definitely a go to for “why not a solid”

Boolean vs Join

The way i would view it is boolean for solids, join for surfaces (that are edge to edge) if surfaces overlap in the middle somewhere, you would want to “trim” first.

Boolean is actually trim-join-remove rolled into one. So it “CAN” give results with surfaces, but just not the habit to create.

BurrMan, thank you. When dealing with surfaces, I'll first try joining with "Edit | Join".

Thanks to everyone's help, I was able to create the model. Thank you.




It's not quite the shape I wanted yet, but I've learned a lot in the process.

marzRX