Problem with hollow extrusions from sketch

[Keith.Turner2]

I've never had this problem before only since upgrade to 2009. Almost any sketch shape that is 'hollow' will not extrude as a hollow. Inventor will not see the inner boundary shape no matter how simple or complex, even something as simple as a pipe extrudes as a solid bar. Often I have to share the sketch & 'extrude' the bore as a seperate action - WHY?

[mflayler]

Care to post an example of this. It might be in how you construct your sketch or your possible non use of a select other tool.

[Keith.Turner2]

I can post an example, but I am getting the problem with a sketch as simple as two concentric circles to produce a pipe! I have used quite a few versions of Inventor over the last six or seven years & never had this problem before.

[JD Mather]

I can post an example,

Still waiting!
I would think that would be the obvious first step - post the file and see if it produces the same behavior on other machines.

[jonathan.landeros]

Posting the part would be ideal. I attached a part and an image of what I get by default. The only thing that comes to mind is if the part is set to extrude as a surface versus a solid (see attached).

[mflayler]

I just tried it with IV2009 SP1 with Bonus Pack 1 and Inventor 2010 and had no problems. A couple things to check might be your Hardware tab in your Application options and make sure you are running Direct3D and that you have the latest certified driver for you graphics card. Beyond that try a newer uncertified one too :)

You might also want to post your entire systems specs to see if something stands out and check to make sure you have SP1 and hotfixes in too.

[Keith.Turner2]

Apologies I have had to do some urgent Autocad 2D work as soon as I can get a bit of time back on Inventor I will send a file It gets a bit manic here as I am pretty well on my own & we are busy despite current state of engineering!

[Keith.Turner2]

This is one Part I had a problem with extruding cutouts I had to extrude the holes in two goes sharing the sketch.

[JD Mather]

This is one Part I had a problem with extruding cutouts I had to extrude the holes in two goes sharing the sketch.

I was able to do it with one extrude using your sketch - don't know why your first pick ignored some of the boxes. But that is all besides the point - I would suggest you change your modeling technique to almost always use Feature Pattern rather than Sketch Pattern.

Do an experiment - Edit your first sketch and then right click in the graphics window and select Show All Constraints. What a mess. Inventor has to simultaneously solve all of those constraints when you use a sketch pattern.

You should also be using more = constraints rather than duplicate dimensions.

The attached is how I might do the part. Pull the red End of Part marker down step-by-step. Edit Sketch1 and Show All Constraints. Notice how many fewer dimensions and constraints control the geometry. What if this was a 100 or 1000 part assembly?

[Keith.Turner2]

Thanks for that, you are absolutely right of course the sketch with constraints visible is a mess! I should know better I've been using Inventor long enough! But it is strange some times I get so 'into' the way I want the final item to look that I forget my basic design intent - I should stop & think more often! but sometimes easy to forget when under pressure to get the job done.

[JD Mather]

... under pressure to get the job done.

That's when understanding robust techniques really comes in handy. Saves time and far more predictable. I shudder when I look at jobs I did last year, even last month... ...continuous learning process.