I want cut on cylinder surface like this.
in Fusion 360 I can draw a scketch, then split surface, pull in or out.
in blender I can extrude in or out.

My question is : how to do it in Moi 3D in a speedy way.





I managed project lines on the cylinder's surface, but it cut the whole cylinder to split object.

Via the Draw Solid Menu: Draw a solid cylinder. Draw a solid box.

Click on each object one at a time, and using the Edit Size feature in the upper right of the screen, change the dimensions as needed.

Position your thin box so it intersects the cylinder to the desired depth.

In the Construct menu, choose Boolean > Diff.

Pick the cylinder as the base object, and the thin box as the item to subtract.

The result is a thin slot in the cylinder.

Another method is to draw a thin rectangle where you want the slot, then Extrude the rectangle (with Cap Ends selected) to the desired depth. Then Boolean Diff the two objects as described above.

More Info:
http://moi3d.com/4.0/docs/moi_command_reference7.htm#Construct_Boolean

Ed Ferguson

thx, but not a speedy way.

Hi Jack, I drew a cylinder and 2 rectangles like this:



Select the 2 rectangles and use Construct > Boolean > Union on them:



Select the cylinder, and run Edit > Trim. Pick the rectangles as the cutting object (Trim has projection of planar curves used as cutting objects built in so you do not need to do a separate projection step). At the prompt in the Trim command where you select what pieces to discard just right-click or push "Done" without selecting anything to keep all the pieces.

Select this piece and run Construct > Offset > Shell to thicken it into a solid.



That will make this piece:



Select the outer face of that piece and delete it:



Join the pieces together into a solid:



- Michael

awesome, learned Shell can be used in this way.

@jack - I have some ideas on simplifying this some more in the future by also incorporating the trimming directly into the Extrude command and then having an option there for a straight directional extrude or an offset/shell type construction.

There is one related piece of that built into Extrude currently which is that if you have split a face like this (using Edit > Trim with "Keep all joined" option):



You can then run Construct > Extrude on the selected face which will directly make this kind of result without needing to delete the outer face:



That's the automatic boolean function in the Extrude command, if you extrude a face of a solid it will automatically do a boolean operation on the solid with the result of the extrude, either a boolean difference if you extrude the face down into the solid or boolean union if you extrude it outside the solid.

So you can use that for other kinds of push/pull like stuff currently where you don't need offset surfaces.

- Michael

sorry, in my case , I tried extrude, nothing happened. your suggestion seems fit for flat surface, not cylinder.

Hi jack, yes that's correct you can't use Extrude currently on your cylinder case because Extrude generates a result that goes in one single direction vector. It doesn't necessarily have to be a flat surface, it can be a curved surface like this:



Then extrude of that will make this result:



For Extrude the "side walls" are all straight lines going in one single common direction:



But for the cylinder that's not going to work, the cylinder needs an offset surface constructed which makes a surface that is displaced along the original's surface normal and not just in one single direction.

I just wanted to mention that if you have some other situation where extrude would do what you need then a quick way is to use Trim to cut up a face of a solid and then select the face to extrude, then you get the automatic boolean without any added steps for "delete outer face" and join. That's the one that does the quickest "push/pull" type action currently.

- Michael

There is another one very speedy but... :)

The Flow Function

"... thx, but not a speedy way."

Just to be clear, you changed your images after I replied. I was responding to the vertical slot and using boolean diff to create it.

If performing a simple boolean operation is not speedy enough, then I don't know what is.

To address your latest images:

I would have created the cylinder in MoI with the horizontal groove in a single operation using Revolve with a profile curve that included a notch for the groove.
Then create each vertical groove by extruding a rectangle and Boolean Diff with the cylinder.

Practice will make very speedy.

Ed Ferguson

I think this caused by misunderstanding, but thank you sincerely.

I tried all method in this thread, use "Shell" fit my purpose.