Cut a slot in a cylinder

[cunninghammarkw]

Hi I am a new user and still getting to grips with this package, I have a part which is a bunch of cylinders making a type of post. I need to cut a slot right through the top a bit like a milling operation. Any help with this would be greatly appreciated.

[nightoftheroundtable]

have you tryed using boolean?

[cunninghammarkw]

Ah another term I havent seen in the software yet. I'll have a look in the manual.

[nightoftheroundtable]

there is a tool bar on ac3d if you scroll down you will see something called boolean.

I think if you use that it will work

[Stiglr]

Ewwww...Booleans are rather messy.

If it works really nice, and the slot looks good, fine...

But if it leaves a mess, like it does with other similar operations, try this.

Use a rectangle as a Knife to cut the dimensions of the slot through the cylinder, and remove it. Fill in the "inside edges" of the slot after you remove the outer area.

[nightoftheroundtable]

I do agree that booleans are messy but they do get the job done. in any case from what I have noticed when using boolean is that it creates an exact duplicate of your model thus having more polys and surfaces.

I would rather go with knife. but the boolean was a suggestion.

[Stiglr]

You can set the boolean up NOT to create a second shape, but to discard the original.

[nightoftheroundtable]

how would that be done I am still a noob when it comes to using boolean

[Stiglr]

In the dialog where you set the A and B operands of the Boolean, check the little box that says something like, "Keep original" or something like that. Check it for both the operands and I believe the result should be just the cut piece remains.

I say should because I've had some problems getting the results I have wanted with Booleans... but, what you want IS possible in some way. Monkey around with the settings and you'll stumble on it.

[nightoftheroundtable]

okay thanks alot

[eldonb]

Are you looking for something like shown below, where the slot can be cut into one surface (facet) of the cylinder?

If so, here is a solution;
1. select opposit surfaces, "Make a Hole"
2. Select all four verts of both holes (8 verts total)
3. "Create Convex Surface/Object"
4. Select and delete slot openning surfaces
5. if you want, "merge" the objects (the hole liner and the post) into one

More complex requirements (e.g., cross slots) would require a slightly more complex solution.

Or - if you are just trying to create the "illusion" of a slot for something like a rail, just create the rail to pass through the post, as in the last example, but then this is not what you asked for - :)

The AC3D (.ac) file for this can be obtained at:

http://www.mr-fab.com/gallery/AC3D/Examples/Post01.ac

Other people on the forum may have other ideas.

Good luck with your project!
Eldon

http://www.mr-fab.com/gallery/AC3D/Examples/Post01.png

and

http://www.mr-fab.com/gallery/AC3D/Examples/Post01s.png

The illusion:

http://www.mr-fab.com/gallery/AC3D/Examples/Post02.png