Extruding a sketch at an angle

[robertmain]

So, from my other post here I've been trying to draw on the reverse of the YZ plane. The thing is that now I want to firstly extrude that drawing at a 7 degree from the plane(ideally using construction geometry from the XY plane to determine that angle - I don't know if that's possible or not...). From there, I want to do more sketching on the extruded slope.

Basically, I'm going to be recreating the bottom part of this but offset at 7 degrees perpendicular to the YZ plane. Wondered if anyone had any insight on what I'm trying to accomplish here...

EDIT: My system stats

OS: Debian GNU/Linux 9 (stretch)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16131 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.18.3)
Hash: 3129ae4296e40ed20e7b3d460b86e6969acbe1c3
Python version: 3.6.7
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)

[freedman]

Make a datum plane off axis 7 degrees, sketch on that plane. If you want the object flush with a standard plane then pocket cut the object at the standard plane edge.

[robertmain]

...huh. Thanks.

I kind of wondered if a custom plane was the best way to do this but I didn't want to rush into it just to find it was kind of a hacky workaround

[Vincent B]

Something like that?
use a sketch on the right plane, draw a path and make a sweep along this path.

[robertmain]

I...think so?

I've created a new datum plane and set the pitch angle to 7 degrees and it looks to be about what I'd expect...

plane.png (22.56 KiB) Viewed 1447 times

The only thing to do now is to find a way to re-orient my sketch on to that plane. I notice it doesn't show up in the "Re-orient sketch" dialog. Presumably I have to use "Map sketch to face" to do this instead?

[chrisb]

If you have a DatumPlane you can indeed map the sketch to that plane.
If you want to turn the sketch independently you can edit the AttachmentOffset.
If you want to attach the sketch to something else you can click on MapMode in the Data tab and then on the button appearing to the right. This will lead you to the attachment dialog.

[robertmain]

If you have a DatumPlane you can indeed map the sketch to that plane.
If you want to turn the sketch independently you can edit the AttachmentOffset.
If you want to attach the sketch to something else you can click on MapMode in the Data tab and then on the button appearing to the right. This will lead you to the attachment dialog.

Looks like that worked, thank you!

[robertmain]

One final thing...

I want to sketch several things on top of that extrusion....

Basically I want a thin cylinder with a wider one on top to create a mounting point. Kind of like a cylindrical "T" shape(like on the base of this). The only problem is that having created the first thin cylinder, I can't then extrude something else from the same sketch. Would I need to create a plane for the wider cylinder on the top offset to pull this off?

[papyblaise]

Hello
be carfull something about the firstquestion, if you extrude a circle along a path whith an angle your pad isn't cylindrical but eliptical , the best solution is extrude perpendicular at the side of the L chape and cut it by a angle.
for the second (tube whith external conical cylinder) the best practice is : do first a cone and drill it by a hole

[chrisb]

You can extrude - or rather pad - from the same sketch, but the diameter of the cylinder would not change. You can introduce another DatumPLane, but I would rather use the previous one and set the z-position of the sketch with an expression to the length of the previous cylinder.