"cut normal" not working on negative Coordinates

[markus.weizinger]

Hi all,

I have a Tube created with a turning operation.

The complete part is on the positive side of the center point of the y axis

The Extrusion is working.

When I move the turing sketch onto the negative side of the center point, the "normal cut" extrusion stops working.

This behavior changes, when the part is not a tube but a reduction. Or when the Tube is created by an extrusion.

Sometimes it works sometimes it does not. There is no real pattern.

Has someone a solution or explanation?

I need this to work in every szenario for a heavly automated process.

Thanks in adavance

[JDMather]

Why not use Sheet Metal functions to create this model rather than Revolution and Extrude?

Why not fully define sketches?

[johnsonshiue · Accepted solution]

Hi! This has something to do with Unfold/Refold. Somehow Inventor has hard time unfolding or refolding the body after the cut is made (to create the proper cut faces). There are workarounds when it happens.

Option1: Move EOP above the Cut. Thicken -> uncheck Auto-Blending -> pick the gap face -> set a small distance. Repeat the step to the other gap face. Move EOP to the bottom.

Thicken creates short planar faces with straight edges so the Unfold/Refold has a clear reference to start.

Option2: Edit Cut2 -> uncheck "Cut Normal." Thicken -> uncheck Auto-Blending -> pick the inner cylindrical face -> set distance = 3cm (thickness) -> set operation to Intersect -> pick the logical direction. Repeat the process from outside.

Many thanks!

[markus.weizinger]

You are right, the sketch is not fully defined. I wanted to illustrade my problem with a simple part.

How would you create a reducer with a defined total length? (Here From Edge to Edge 15)

[markus.weizinger]

Hi,

Your Option 1 works kind of. On my first try i chose a small Value (0.0001) to keep the changes minimal. On my particluar Example the minimum Value to make this option work was 0.001. Otherwise i get the same Error. Is there a way to say what will work an what not?

As i mentioned i need this for an automated prozess. The Part can be a tube as well as a reducer. Your Option 2 works great for a reducer. But not for a tube. If the part is a tube then there are no changes made with the second thickening operation. So i get another Error.

Thanks