Cut object in half and have it separated


#1

Hi,

I already asked this question in another month and the answer at that time was good but not good anymore to my current case.

I want to slice in the middle this object Suporte da câmera.skp (1.5 MB)

BUT I WANT to slice it in a way that the 2 parts left can be easily draged out, I mean, I can easily separate the 2 parts (moving them apart). All the methods I find online of creating section planes or using a rectangle as a cutting tool create just the shape of the cutted area and after that I have to very carefully delete the part that I dont want and doing so I have to spend minutes and minutes selecting all the lines and stuff I dont want.

I also want that those 2 parts still remain a solid cause sometimes when I cut some objects using section planes those objects are not solid anymore and I need to carefully inspect what went wrong and fix creating lines in some nodes.

Is there a reliable way to slice an object and have its sliced parts easily moved/dragged apart?


#2

Which way do you want the slice to run?

Yes. But you need to provide more information.

And the first thing you’ll need to do in the process is clean up the lousy geometry and make the original group solid.

How did you draw this thing, anyway?


#3

I want the slice to be done frop the flat top to the bottom right in the middle (vertical cut). But I would like to learn how to do this by myself cause in the future I may want to cut this object horizontally.


#4

Well, before I can show you how to cut it, I’m repairing it to make it a clean and useful model.Getting rid of a lot of garbage.

What diameter are the holes and counterbores suppose to have? They are weird, seemingly random dimensions. I’m puzzled as to why you would work on something as small as this with such coarse precision for the Units.


#5

Is this what you want to achieve? Both halves are solids.


#6

Exactlly! This part is gonna be used in a camera tripod. The precision does not matter so much. In one of you replies you are saying you were trying to get rid of garbages inside of this model. I would like to learn how to do that cause everytime I downloaded and STL and import it to skecthup it gets really weird, with tons of unecessary lines and gemotries.


#7

the precision does matter when you are drawing it. Part of your problem is the precision setting you are using is much too coarse for the size of the objects you’re drawing. This makes it hard for you to get good results. It’s as if you’re trying to make baby spoons with a chainsaw.

There was so much bad geometry in your model it was easier to abandon it and redraw the part from scratch. By starting with clean edges, it was a simple matter of making a solid component. I also limited the number of sides on the circles to 48. You had them at 180 sides which for the small size of the holes is ridiculous overkill. It created a bunch of liabilities with no real benefits.

After I had the shape drawn, I made it a component and confirmed it to be solid. (It was from the beginning.)
Next, I opened it for editing and drew a cutting plane through the center of it…

…and used Intersect Faces to cut the faces at the cutting plane.

The next steps make it possible to have the left and right halves but you have to follow along exactly.

Create two layers, one called “Left” and the other called, "Right"
Select the component and hit Edit>Copy to copy it to the clipboard.
Select the component and assign it to the Left layer.
Turn off the visibility for the Left layer.
Hit Edit>Paste in place.
While the pasted copy of the component is selected, assign it to the Right layer.
Right click on it and choose Make Unique.
Set the camera to Parallel Projection and Top View.
Open the component for editing.
With right to left selections, select the left half of the component.
Hit Delete.
Erase the edges of cutting plane.
Correct the face orientation along the cut line if needed.
close that component and turn off the visibility of the Right layer.
Turn on the visibility of the Left layer
Repeat the steps of editing the component but this time remove the right side instead.

That same process will work if you want to split it horizontal and for any other shape.

In the case of the left/right split, if one was thinking ahead a couple of steps, you could leave out the counterbore on the near leg. Split the component in half and then copy and flip to make the counterpart. Make unique and then add the counterbore in the approriate location.

If you make a good clean selection of the half after the Intersect routing has completed, you could move a copy off to one side and then erase the original half.


#8

Wowo man that’s worked!!! That’s amazing, I did it all by myself to make sure I understood right and it was amazing easy how precise you were in your description! It’s a shame that skecthup does not make this slice problem easy, anyway, using layers as you said worked perfectly!

The number os segmetns used in the “circles” came from skecthup parsing a STL file that I imported. I usually make no more than 12 segments to circles.

At least now it’s fixed thanks to you!


#9

I’m glad that helped. There are other ways to do this but they are just variations on the theme and the end result is the same.


#10

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