Newbie Question: Extrude in Edit Sketch mode vs. Extrude in normal mode?

john_smith077

Hello

Please my I ask some naive questions:

Is there any difference between Extruding in Edit Sketch mode or normal (/Part?) mode - How come you can do Extrude (and Revolve) in both menus and does it matter which you use?

Many thanks

P.S. To be honest, I'm still slightly hazy about several of the core concepts in CAD/Onshape.

If you can humour me, it would be *extremely* helpful to me, to have some loose/layman speak  definition of terms. [Aside: Overly precise technical definitions only seem to confuse me!]

So a "Sketch" is a collection of "stuff" - 2D stuff - that can then be Extruded to create a 3D "Part".

The 2D stuff in a Sketch might consist of: 

- Points (that may or may not be joined to form 'vertices' between two edges) 

- Edges (i.e. straight lines between two points/vertices)  

- Shapes (i.e. collections of Edges) appear in Edit Sketch mode as: 

     - Lines, Rectangles, Circles, Arcs, Polygons, Spline curves, Text

- Some shapes in a Sketch are Closed Shapes (i.e. a 2D collection of lines that totally enclose a space. Loosely: Where a collection of lines go back to where they started.)

A "Part" is where one or more shapes has been extruded into 3D.

An "Assembly" is a collection of Parts.

- Shapes can be 'parametric' meaning roughly: they are built up in a hierarchy of data variables (called Constraints), many of which depend on each other, so any of them can easily be changed at a later date without destroying the integrity of design of the the whole Part... [something like that??].       

  

A "Feature" is... erm, something that has been done to a 2D parametric Shape? [Am I close?]

OK, I give up. I told you I needed a Glossary! 

3dcad

john_smith077 said:

Thanks - I find it slightly strange that extrude is even part of a Sketch...  :^/ 

Think it like you had shortcut to a program on your desktop and quick launch / start menu, it's there just to make simple things fast and easy.

About terms, I once started to translate Alibre in Finnish language - pretty soon I noticed I don't know what words sketch, extrusion, sweep, loft etc. means but I know what happens if I click them. I decided not to translate since it would just make things confusing.

Today, I still don't know what they mean (in Finnish), but I know what they do and have figured out how to use them. That is enough to be able to design with intent, terms are only needed when communicating about cad with another person.   

I have noticed that you don't hesitate to ask a question, that's good - but you would learn a lot of basics by searching the forum and reading those few pages discussions about various interesting questions following multiple answers.

During the beta, I read every single thread no matter which topic it had - I did learn a lot of stuff about Onshape, cad in general and differences between other cads (which I haven't used) vs Onshape. And it has been a very good English lesson for non-native user like me.

_Ðave_

Lets say that you have two circles in a sketch. if you extrude while still in sketch edit mode you will extrude both circles.
If sketch edit mode is turned off and you extrude you can choose one or both circles to extrude. HTH

john_smith077

_Dave_ said:

Lets say that you have two circles in a sketch. if you extrude while still in sketch edit mode you will extrude both circles.
If sketch edit mode is turned off and you extrude you can choose one or both circles to extrude. HTH

Thanks - I find it slightly strange that extrude is even part of a Sketch...  :^/ 

_Ðave_

You can also extrude a face of an existing part. otherwise you would need some geometry to define your extrude.

michael3424

Would it help to think of an extrusion as the transition between a sketch and a 3D part?

3dcad

john_smith077 said:

Thanks - I find it slightly strange that extrude is even part of a Sketch...  :^/ 

Think it like you had shortcut to a program on your desktop and quick launch / start menu, it's there just to make simple things fast and easy.

About terms, I once started to translate Alibre in Finnish language - pretty soon I noticed I don't know what words sketch, extrusion, sweep, loft etc. means but I know what happens if I click them. I decided not to translate since it would just make things confusing.

Today, I still don't know what they mean (in Finnish), but I know what they do and have figured out how to use them. That is enough to be able to design with intent, terms are only needed when communicating about cad with another person.   

I have noticed that you don't hesitate to ask a question, that's good - but you would learn a lot of basics by searching the forum and reading those few pages discussions about various interesting questions following multiple answers.

During the beta, I read every single thread no matter which topic it had - I did learn a lot of stuff about Onshape, cad in general and differences between other cads (which I haven't used) vs Onshape. And it has been a very good English lesson for non-native user like me.

john_smith077

OK I'll try. When I get stuck, I do always search for answers both in the forum and elsewhere. I have also found re-watching one or two of the beginner's videos is quite helpful. Some of them are so fast that it's almost impossible to take it all in 1st time around...   But there is a limit to how much time I can throw at all this!