Offset Problem 2

(First post) Sorry to jump in someone elses thread, but this is recent and I'm having similar issues. I need to offset a projected loop in order to cut/extrude into the part. I have tried offsetting each element individually and trying to trim/join into a closed loop, I also tried offsetting only the long edges to fillet the corners but the offset lines are not selectable in the active fillet command???

This is the 4th part of 4 similar parts - the first 2 I did easily, the final 2 are proving difficult.

I'm really struggling here, any suggestions?

Thanks in advance

I'm really struggling here, any suggestions?

Here's a logical suggestion - attach the file here.

File attached, also a pdf of what I am trying to achieve. The first one was offset>extrude/cut>chamfered.

Thanks

punch.zip

I think I would have started a new thread for this problem rather than piggy-back on a solved problem.

I would dramatically simplify the model by using arcs rather than spline you have in Sketch1. You can use 3 points to determine each arc needed.

Given normal manufacturing tolerances some of the arcs are sooooo close in radius that they could be replaced with one arc (and still be within several magnitudes of realistic tolerance).

Arcs will simplify the g-code as well.

I created a new thread in Autodesk Inventor forum called Offset Problem 2.

Thanks for taking the time to look.

The spline is projected geometry from the customer supplied model, no 'paper data' exists to re-create the shape.

You are right about the tolerance factor though, the outside needs to be correct and will be wire eroded to the spline, but internally it is not so important.

I offset every other curve and connected the gaps with tangential arcs. This seems to have done the trick.

Thanks again