Cannot Part Extrude face with a taper - drawn in DRAFT wb

[miniellipse]

I would like to Part Extrude this face that I drew in DRAFT WB with a TAPER (of about 10-20 degrees). The command results in my face disappearing and the red exclamation point beside the Extrude (the hover error over it shows, "Tapered Shape is Empty.")

I've tried neg and pos tapers and they don't work. Taper of zero deg works. I checked the wiki on the command and maybe this is my problem, but I'm not good enough to understand if it is: "It also may give bogus results if the number of segments in the profile changes as a result of taper. " https://www.freecadweb.org/wiki/Part_Extrude

Screen Shot 2018-11-02 at 10.56.48 AM.jpeg (110.55 KiB) Viewed 1467 times

I also used the "Check Geometry" command and it shows no invalid faces:

cover_remote_1.Face:
VERTEX : 4
EDGE : 4
WIRE : 1
FACE : 1
SHELL : 0
SOLID : 0
COMPSOLID : 0
COMPOUND : 0
SHAPE : 10

Any help is appreciated. My file is attached. Thanks.



OS: macOS Sierra (10.12)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.14779 (Git)
Build type: Release
Branch: (HEAD detached at 50ab6e2)
Hash: 50ab6e292cc83cada4a5b071531a76f5a2580f60
Python version: 2.7.15
Qt version: 5.11.1
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

[DeepSOIC]

I'm sorry, but 2d offset in 'intersection' mode fails on your shape. It's OCC problem, there's not much we can do about it.

Some options are:
* 2d offset works in 'arc' mode. You can use that to achieve a tapered extrusion by moving the offset and creating a Loft between.
* maybe SlopedPlanesMacro can give usable results?

[damian]

* maybe SlopedPlanesMacro can give usable results?

Well, I draw a sketch, approximately like your face, and I can extrude it. But, as you can see, I could have problems with the curved edges, which introduces noise in my geometry. The visible interior line is a problem.

slopedplanes.png (271.59 KiB) Viewed 1459 times

The seed problem is incorrect parameters for the curved edge to be extruded. With the time I hope a decent solution for this.
EDIT: with another radius for the arc of circle the geometry is ok

[damian]

For instance

slopedplanes_2.png (258.83 KiB) Viewed 1458 times

EDIT: @miniellipse, I preserve your file in order to activate the option to use slopedplanes macro directly with a Part Face

[miniellipse]

@DeepSOIC: OK. I was trying to save a few steps. I will use Loft for the taper effect.

@Damian: Thank you for trying that macro. That curve is important to me, so I cannot make it into a curve. That stray line is caused by the bezier curve as it connects to that straight line. I thought I made all the end points coincident (which was very hard to do).

[damian]

I thought I made all the end points coincident (which was very hard to do).

Yes, I know.
The slopedplanes macro doesn't support splines or Bezier curves, ATM.

[miniellipse]

hey guys,

I'm still struggling LOFT does not work on this either. Is this the problem with beziers? I can't believe something so simple cannot be done.
file is attached.

I took my previous face, mirrored it, downgraded things into EDGES. cleaned them up, and then upgraded the items back into a wire. I scaled the wire into a new smaller wire (85%). I had to use Scale because the OFFSET in Draft WB failed to work. I then upgraded the two wires into a bottom and to face and then applied the LOFT. The result fails quite badly.

cover-remote-3.FCStd

(237.61 KiB) Downloaded 20 times

[chrisb]

You have set "Closed" to true. Set it to false.

[miniellipse]

You have set "Closed" to true. Set it to false.

Argh...Thanks. I thought I tried that. But now it works. Thank you, Chris!

[chrisb]

Argh...Thanks. I thought I tried that.

You're welcome. I have found out by deleting and recreating the loft.