Derived Part Sketch Rotation issue

[Anonymous]

Hi everyone, 

I'm having a pesky issue that has been bothering me for a while, and wonder if anyone else has an idea, my boss and I are stumped. 

Basically what we are doing is drawing sprocket profiles and using derived parts to create 3 separate stages of fabrication, for different manufacturing methods. 

For example I create 'Part 1a' and then begin 'Part 1b' which is 1a plus some holes etc. 

The issue is when I select the face of the derived part to begin a new sketch on it, it rotates off axis for some reason, it's like it is picking up the geometry of the existing profile of the sprocket and 'snapping' the axis to that.

I'll attach a screencast and the corresponding part to explain my issue further. Please take into account the position of the view cube. I have not rotated it, this is the rotation I am having an issue with. 

Ideally, I would like the origin of the sketch to be the same as the derived part. 

Thanks in advance,

Tim. 

[EvanGu]

Hi Tim,

This is exactly an issue that we are going to solve.

In your attached file, when creating a new sketch from a face of Face1 feature, the sketch coordinate system is reused from Sketch1 consumed in Face1. However, in the derived part, there is no sketch for reference, so the method to get the coordinate system is different, and probably get different result. To avoid the rotation, please don't create sketch on the face directly. Instead, create a workplane on the face by offsetting XY plane, then continue to create sketches in the workplane.

We plan to enhance it to get a more reasonable result in case2.

[Anonymous]

Maybe you can try to create new workplane - in plane menu try to create new plane using "offset from plane" . Is the part rotating now?