Can't get extrude working correctly

[AK_11362522]

I am using Creo Parametric 10.0.2.0

Background: I am an experienced Electrical Engineer, have used AutoCAD my whole career, mostly 2-D but have done 3-D objects. I recently learned Altium and have done 2-D and 3-D modeling there. I have used Creo to view objects in the past as well as creating assemblies with pre-existing 3-D models. In short, I have background in CAD and 3-D modeling, and in Creo, but not in Creo 3-D modeling from scratch. However, today I have been asked for the first time to create a 3-D model in Creo - and I am struggling.

I am starting with the simplest model imaginable, but I have yet to grasp it. I just need a flat panel. The panel is a flat rectangle with small rectangular "ears" with a thickness of 1.5 mm.. I created a sketch of 3 rectangles: one large and two small rectangles each on the center of the long side. Should be easy, I should just need to extrude it with a dimension of 1.5 mm at this point.

Obviously, extrude from surface is the wrong choice - I'm only mentioning it here, because it "works" and does what I expect. However, it of course just extrudes the lines of my sketch, so I get three hollow rectangles with a 1.5 mm thick frame around it. That is not what I need, I need this to be a solid.

If I try to extrude from solid, one of three things happen. Sometimes, It won't even let me select my sketch. Other times, my sketch is selected, but it won't let me use a thickness of less than 590 mm. And lastly, sometimes it lets me put in my 1.5 mm thickness, but then the whole thing becomes invisible.

My next thought is well, my sketch isn't solid, it's just the outlines, so I need to make it a solid plane. However, nothing I have tried works. Fill won't let me select it, and solidify is greyed out,

I'm sure I'm missing something fundamental and easy here, but I've watched multiple videos and I haven't figured out what I'm doing different / wrong so I appreciate any help that someone can offer.

[tbraxton]

I suspect this is the issue that you are having. Activate the feature requirements and a window will indicate the problems with your sketch.

[AK_11362522]

I have two issues under Feature Requirements:.

     A yellow triangle: "intersecting entities encountered in the section"

     A red circle which just has "Basic Requirements".

"Basic Requirements" is not a very helpful error message.

[tbraxton]

Wath this video as a start: Creo Parametric - Sketch Mode Basics (youtube.com)

[tbraxton]

The sketch will be filled as seen below when it is "valid".

[AK_11362522 · Accepted solution]

So, this didn't quite answer my question but it definitely got me pointed in the right direction. The key for me was realizing that Creo doesn't merge or otherwise resolve separate objects that intersect in the sketch. I had to remove the intersecting lines and redraw them as one object.

To that end, for my final solution, I completely redid my model and instead of using rectangle I used all lines (and arcs). I started with construction lines first. Since my model was symmetrical, I focused on just one quadrant. I drew in my construction lines and set them to proper dimensions and constraints, then once they were set I traced over them with my real lines. Note: My real end goal had rounded corners and some slots, so the construction lines helped make sure I started / stopped the straight lines in the right locations for the rounded corners as well. I was able to sketch it out all at once using the path I set with the construction lines. Once I was done with 1/4 of the sketch, I selected all, mirrored horizontally, then selected all again and mirrored vertically and that automatically closed the loops and gave me a valid sketch. I was then able to extrude it to the 1.5 mm thickness I needed.

Alternately, I could have used the rectangle draw just for construction lines, then traced those over with the real lines after - which I probably would do in the future for anything that wasn't as symmetric as this part.

Thank you. 

[tbraxton]

In the future if you submit questions, you should note the version of the software and whether it is a commercial or educational license.  Posting the models or an example data set that allows others to query them is also advisable. You can save sketches but posting your parts/assemblies is best.

If you plan to use Creo for modeling, I encourage you to watch the videos from the same author I linked above on best and bad practices. This will help you to avoid much frustration.