## Flatten top

This forum is for general discussion about Aspire

### Flatten top

Here's what I'm trying to do (let met know if there is a better way)...

3D Modeling. I have a large round disk shape with a slightly domed top. I want to flatten part of this dome. I created a disk of the appropriate diameter I want to flatten. I set the mode of the disk to SUBTRACT. All well and good. Now, how to I lower and raise this disk above the dome? I want to flatten the top 1/4" of the dome. Is this the correct procedure?

gkas
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### Re: Flatten top

Am I in the ball park?

John
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highpockets
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### Re: Flatten top

If John’s (highpockets) example isn’t what you are trying to describe, then please make a hand drawing of what you want and post a picture of it here. I’m certain it’s very simple to do, but a drawing would help us help you! (Unless John has already nailed it, that is!)
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mtylerfl
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### Re: Flatten top

If you flattened the top dome, then yes.

I want to flatten the top third off the dome, basically slice it off a third of the way down. I thought of setting a thick disk down from the top, then putting the disk in subtract mode.

I guess I'm trying to figure out how to subtract a 3D shape from a 3D shape. ie; drop a cube into a sphere. The cube would be lowered into the sphere a third of the sphere height. I can figure how to draw the shapes and use the combine modes, but how do I extrude a shape and suspend it 1" from the floor.

Another example from another thread would be connecting a length 1" square rod to a length of 3/4" round dowel. A round tenon protruding from larger square stock.

Am I making sense?

gkas
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### Re: Flatten top

Here's how I did it. The problem with your way is in Vectric you can have undercut areas.

The other way to do it would be to subtract a plug from the dome then merge a cylindrical component.

John
Maker of Chips

highpockets
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### Re: Flatten top

LOL!!!
OK here's a fun way (that cat again).

With the dome as a start.
Get the height of the dome
Draw a square vector slightly less than the diameter of the base of the dome. Make sure it's center of the dome.
Create a shape using the square vector, Flat Profile, Base Height of Dome height minus .25"
Use the Measure tool with Model Cross Section checked.
Draw a vector through the center of the dome longer than the dome.
This will create a profile of the dome and square showing exactly where the square touches the dome.
Now create a circle the size of the points where the square and dome meet.
Use the circle to create a shape using the circle vector, Flat Profile, Base Height of Dome and Subtract Mode
Duplicate the new Component
Set the Combine Mode to Merge

John
Maker of Chips

highpockets
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### Re: Flatten top

Damn cat!

Dome, use Slice Visible Model, Set Slice thickness to height of Dome - .25". Keep Slice 1
John
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highpockets
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### Re: Flatten top

Thanks, I got both methods to work.... But I'm still not positive why the first one does. I think I have to study the MULTIPLY mode. I don't think it's uses are as simple as the name implies. I'm definitely going to have to roll this around in the noggin awhile.

Thanks again...

Gerry

gkas
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### Re: Flatten top

I did use example #2 to slice the top off the model. The Material Setup was complaining that the model was too thick for the stock. I'm using a 2D pocket as my last step to remove that material. Setup was real happy after I sliced off the top of the model where the pocket was going.

My extra bonus was your mentioning "Use the Measure tool with Model Cross Section checked.". That is a FANTASTIC option that I had not really noticed before. It sure simplifies a lot of calculations.

thanks again....

Gerry K.

gkas
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### Re: Flatten top

John,
That was a +1 , +1, +1
Thank you both - very educational.
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WNC_Ed
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### Re: Flatten top

Option two was fun to do and the Model Cross Section is a great little tool that's hidden away. But I prefer Option 3, it's much easier to just Slice the model where you want it.
John
Maker of Chips

highpockets
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