Hi MoI friends,

I have some troubles I would like to understand... Well... In fact I have again some trouble to try to understand yet ! ;-)

A behavior I have difficulties is the fillet tool.
I understood all is not simple in fillets cases, but I would like to understand why my fillet at the bottom of my piece cannot be set wider than 0,82mm, and why at 0,82mm it does not end without a planar surface.
I would like to obtain a fillet all around my piece, as I have already rounded some edges as you can see.

The second issue I have is I cannot do a surface to end my elliptic cut, even if I make one closed object with the edges of this cut.
I have to obtain a fillet also for the edges of this cut. (say all the edges of the piece have to be rounded the same way)

Of course the first try I have done was to just select the whole piece and to make a fillet tool, but alas without any success.

In attachment there you will find a sample of my piece to see what can be happened, and I hope (in fact I'm sure ;) that you will be able to explain to me how I can do...

Cordially,

1 Seems that is the maximum angle admissible with the inclined lateral planar face and the top arc-circle 0.99....
If the lateral face was not inclined but perpendicular sure you should go to the same 0.99...

2 Maybe you have made a "Trim" action and not a boolean difference so the volume was stay "open"
and now some actions will be necessary for close it :)

3 when you make a fillet to a whole piece, general fillet is adapted to the less acceptable minimum angle somewhere!

1) I am not sure to understand what you tell Pilou...

2) Yes, I trimmed instead of "booleanned" for cutting with an ellipse but after that trim I have closed the edges of the cut and now it is a "closed crv".
What do you mean by "some actions will be necessary" ? What I have to do ?

3) I understand the whole piece is not quiet to be filleted, that is all my question : how do it have to be ! ;-)

Thanks for your time !

Cordially,

2) if you have made a boolean difference "surface" was be automatic ! No need to close curves etc... :)
Never "Trim" a volume if you want surface! Always use the Boolean Diff between a volume and a curve/surface/curve !

3) now you can can fillet the whole piece!
but the open surface will be not filleted!

you must close it before
alas there not yet close function for close a general hole!
You must make something like this : redraw a middle curve curvated, trim the edges with this new curve, Network etc...
so the boolean Diff was indispensable for avoid all that !!! :)

<<don't understand
1) You can't have an equal "corner bag" because your lateral face is not perpendicular to the body!
So the 0.99... can't be 0.99... but only 0.82 ;)

OK ! Thank you very much this time I think I understood.

So I memorize 2 important informations :
1) to cut with bolean for making closed surface where the cuts are done
2) to be perpendicular with fillet to allow symetrical filleting

Last (but not least be sure ;) do you know a way to positioning a surface exactly perpendicular to the camera (our eye) within the 3D view ?

I know I can take a side view and different tools as construction lines for positioning exactly an object, but it would be so cool to have automatically a surface perpendicularly positionned in front of our eye in 3D than I guess Michael already thought to that, isn't it ?

Edited few minutes later :
in attachment there you will see my issues : the ellipse does not close its bolean cut and the line does not cut very well the base.
Could you tell me where you think I am wrong please ?

Cordially,
Guy

you are not obliged tu put the ellipse on the surface for make a boolean diff ( keep surface) or a Trim (don't keep surface) !

But as your object is actually not a solid , the surface is not created with boolean Diff!

In your case I suspect that you have taken one axe of the ellipse in the 3D space so no // at the surface, so inclined! ;)
Move it on the surface and you will see that is 0.972769° difference!

All that because your object is floating on the 3D space and not alligned to the gride ;)
You can of course don't use the gride but it's very more difficult! :)

You can use the Menu :Vue/"Plan Aux" (CPlane) for temporary use ;)

Not many interest to have perdicular view in 3D view!
With the CPlan actived from your face wanted you have that in the Topview(Cplane) ;)

Hi Guy, yes like Pilou has already been discussing with you for your #2 instead of using "Trim" which is a surface cutting operation you most likely want to use Boolean difference which is a volume cutting operation and is focused on generating solids as the output.

When you cut an solid using boolean difference, the "side walls" of the cutting piece will be incorporated into the result, making the result a solid as well.

Trim is more of a surface modeling operation that only cuts the outer skin of the object - it's a more manual low level tool that you can use if you are working with surfaces instead of solids.

If you are working with solids, it's more convenient to use the boolean operations instead, basically the booleans do a combination of the world of Trim + deciding which pieces to discard automatically based on which volume they are in + Join the pieces back together again. You can get the same result by doing a bunch of those operations yourself manually but it will be a bunch more work.

Here are some other previous examples showing how you want to use booleans to cut your object if you want "side walls" of the cutting object to remain:

http://moi3d.com/forum/index.php?webtag=MOI&msg=5075.3
http://moi3d.com/forum/index.php?webtag=MOI&msg=3883.3

- Michael

Hi Guy, and as far as why you can't make a larger radius fillet in that one place - that's caused by the "bunching" problem where you're asking for a fillet that is a bit larger than the available space for it going around a bend. In your case here since you've got the bottom part slanted that also reduces the space available more than if the end was at a 90 degree angle.

Bunching is like this - trying to make a large radius thing go around a tight bend:




So note there that at a certain size the piece start to stack up over top of one another and make a kind of chaotic self-intersecting area.

If you turn on surface control points for the 0.82 radius fillet piece (use Edit > Separate on it to break it into its own surface first), you can see that it's just about at the limit of that kind of bunching on the tight side, much more than that and the sections start to cross over one another:





- Michael

Hi Guy, and re: booleans - like Pilou if you have a hole in your object making it an open surface rather than a closed volume, then the booleans will behave differently, you are trying to work in this case with a now open surface since you basically "un-solidified" it when you did a trim on it initially instead of a boolean.

See here for some more information on boolean behavior with open surfaces:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5195.14

If you want to use the booleans you usually need your base object to be a solid, and then they will work like you were expecting.

So your initial steps for creating this object would go like this - start with your base solid like so:



Then go to the 2D front view and draw in your curve cutting shape like this:



This looks like this in the 3D view now - it does not matter at what depth level the ellipse happens to be at:



Now, you do NOT need to do any more preparation work - if you're doing stuff like projecting curves on to surfaces and doing trims, that's all a bunch of extra work that you can just skip, instead let the booleans do all that work for you!

To get the final result, just select your solid here, and run Construct > Boolean > Diff, select the 2D ellipse curve as the cutting object and you will then get this result right away:



Check out the attached 3DM file for these objects - it's all set to boolean just run boolean difference and use the ellipse as the cutting object and you're done!

By the way these methods of doing booleans to cut solids with 2D curves is covered in the introductory video tutorials, if you have not watched them before it's probably a good idea to go over those, they will help get you going easier:
http://moi3d.com/2.0/docs/tutorials.htm

Basically if you just want to do simple "drill a hole with a 2D profile", and you have a solid as your base object, just draw in your 2D curve and then do a boolean operation and that handles a bunch of work for you - the booleans handle extruding the 2D shape into a "side wall" cutting object, trimming things and throwing away the right pieces, and then joining those pieces back into a solid so that's a lot of individual steps that you don't have to do when you use the booleans.

It looks like you were previously trying to do a bunch of those steps manually, maybe including even projecting the curve onto the solid before trimming with it? Even that projection step would be extra actually since Trim also has built in projection in it, you usually only need to do projection manually if you want to use the curves for some other purpose than cutting, like if you want to build some sweeps with them as rails or things like that. So there are probably a whole lot of extra steps that you were doing which are not necessary at all.

- Michael

Hi Michael,

Clear ! Thank you very much for all these explanations.
Yes I watched your 3 video tuts, but maybe due to my bad English spoken understanding for sure some teached stuff you told was lost for me...
I am learning English spoken a bit more with audio books, so I hope this will be resolved soon enough O:-)

About what interest us here, I have almost what I needed except one : how can I bolean-cut perpendicularly to my inclined surface in my example ?
Say I need to cut the ellipse perpendicular to the side, but as you know my piece is not straight (surface is curved a bit) nor vertical

So what is the best and clever way to project my cutting bolean axis perpendicular to what I have to cut ?

Cordially,
Guy

Hi Guy, the boolean will cut based on the orientation of the 2D curve, so if you need the cut to be angled you just need to rotate the curve to the angle you require and then use the same steps I described above, you don't need to do any projection this time either.

To do the rotation, go to a side view and then you can do it like this:



There I just drag the ellipse over so that it's centered on an edge of your object and then grab the rotation grip and drag it over and snap on to the same edge.

After that do the same boolean steps that I described above - select the solid and run Construct > Boolean > Diff, select the now rotated curve as the cutting object and it will make this result (also see attached 3DM file):



Hope this helps!

- Michael

Another method
For your ellipse : be sure your big surface is entierely plane
draw the ellipse entierely on the surface, then size it as needing, and move it to the place wished with the helper lines and direct snap enable + gride disable
like this you must be sure that is // to the surface so perpendicular for the Boolean diff ;)

Hello,

Many thanks for your explanations Michael, this lets me understand and learn a bit more :-)
Both methods (yours and Pilou's one) was very good to make my ellipse perpendicular to my surface.

However I prefer to draw directly on the surface with "object snap" enabled because this surface is not really planar, so drawing directly onto it lets the ellipse axis (say hole axis) exactly perpendicular just as I needed.



Thank you very much again for your so precious help ! :-D

Best thinking and cordially yours,
Guy

<< because this surface is not really planar, so drawing directly onto it lets the ellipse axis (say hole axis) exactly perpendicular just as I needed.

You can have surprise if your "surface is not surface really planar" !
In this case you must take some true marks (repères) somewhere!

(A moins que que " not surface really planar" signifie juste inclinée par rapport aux axes ? )

You know Pilou you can draw an ellipse directly on an egg surface, which is yet less planar than my piece was here ! (I'm joking don't worry ;-)

"not really planar" means "not planar" : my surface is rounded as an extruded circle and a bit like a conic one, also.
Yes, I know, a very complex surface for a so simple piece. O:-)
Anyway as you can see on my image - showing your method at the left and Michael's method at the right - this worked well enough :-)

Well, as you have imagined to be exact the ellipse was not all round touching on the "non-planar" surface, but as you understood I just simply drawn my ellipse with its hot points in touch on the surface, then this was enough to obtain my "perpendicular axis" as well as I needed for perpendicularly cutting as it was done.

Cordially,
Guy

It's for a new concept of trimer patatoes ? :)

lol..............

Peace,
Rich_Art. ;-)

Not for potatoes, but for carrots.
And only those that are cooked.

That is a new concept.
Yes, I know, difficult to understand.
But say "thanks" because it is just for this you are still alive. And after thinking, maybe also a bit because the men in black are so busy nowadays... ;oP

Be quiet,
Guy