cant extrude in solidworks 08

[aebstract]

Okay I am new to solidworks, however I am going through a tutorial dvd. There are times that my shapes won't have an arrow to drag to change depth on extrusion when I switch to the extrude tool. If I change my depth manually and click the check it will tell me "the direction of extrusion must be specified for 3d sketch". This happens sometimes, but not always. Is there something I am missing that is causing this to happen sometimes?

 

[JMirisola]

Yes, stop using 3D sketches.

Jeff Mirisola, CSWP, Certified DriveWorks AE

http://designsmarter.typepad.com/jeffs_blog

 

[polykracker]

In the FeatureManager choose a plane normal to the direction that you want to extrude (right below the drop down menu in the Direction 1 window)

 

[rollupswx]

As indicated - at your level the tutorials should not say anything about using 3D sketches. You should be doing 2D sketches. Make sure you recognize the difference between the two icons.
Actually at any level most sketches will be 2D sketches.

 

[richierich316]

One of the requirements for a solid extrusion in a 2D sketch is that the sketch should be a closed entity or have closed entities otherwise it would tend to be thin walled extrusion with a variable thickness which can be defined.

If there is a window for select contours then it means that your sketch has one/many open profiles.

One more thing about extrusion is that it is adding material normal to the sketching plane and in a 3D sketch you can draw in multiple planes at the same time so solidworks cannot find a plane to extrude from and hence it asks you for the direction to extrude so that it can use it as a guide to extrude but if you use a 3D sketch in a single plane then you can specify a direction of extrusion with another sketch which is at an angle other than 0 degrees to the 3D sketch .