Extruding a Sketch to a Depth set by an E

[AdamW]

Afternoon All,

I have recently switched to Solidworks 2010 after using UG NX extensively.

After much searching I have finally found out how to set expressions to control
dimensions - Tools -> Equations!

I have created a sketch (a simple rectangle) and linked the width/height to an
equation.

I now want to extrude the sketch to a depth, also set by an equation. Therefore,
whenever I update the equation, the part will also update.

However, I cannot find a way to link the depth of the extrusion to an equation. It
requires a number in the field.

I have tried setting a random number, creating the extrusion. The double clicking in
the feature tree to show the extruded depth dimension in blue, double click it to try
and link (as per in a sketch), but it just comes up with a text box to enter a new
figure.

Does anyone know how to link an extrusion depth to a equation?



Also, how do you create a plane and link the offset distance to an equation?


All help would be much appreciated.

 

[Mihail]

Welcome to the forum !

Assuming you have a part (an extruded one) do:
In the FEATURE MANAGER right click Annotation and check Show Features Dimensions.
That allow you to see the depth for extrusion.

From now you can set an equation as usual (Tools -> Equations -> Add)

An advice:
Do not use equations if it is not strongly necessary.
If your part is a part of an assembly, edit the part in assembly context and set the extrusion to a plane, a surface, a vertex and so on (see the options for extrude feature in this context).
To edit a part in assembly right click the part (in design tree manager or on screen) and choose Edit Part.
The same advice about sketches. Use IN CONTEXT EDIT.
If you wish to become efficient learn quickly and as more as possible about IN CONTEXT EDIT (from help files).

I use SW 2007 but I think that things are the same in 2010.

Let me know if this help you.
Good luck !


Edited by: Mihail

 

[AdamW]

Hi Mihail,

I have since found a solution to the problem.

However it is interesting to hear you say not to use equations. What is your
reason for this?

I have worked extensively with Unigraphics in a design engineer role and
from the outset was taught to use expressions (same as equations in SW) at
all times. It makes it easy to update a part and linked dimensions, should (as
is often common) a part needs changing.

 

[Mihail]

Hi Adam !
My English is not as strong as I wish.
Look: Contact me on Messenger and I'll try to explain my point.
After that, if someone else is interested, I'll ask you to post the answer using true English (is your language, isn't it?).

Contact me after 5 minutes. OK ?
[email protected]

 

[AdamW]

Hi Mihail,

I do not use messenger unfortunately.

Could you try and explain here? Possibly use an online translator?

 

[Mihail]

OK. I'll try.

The equations are very slow to calculate. Of course, for simple parts is not a problem. This is one point of view but not the most important.
The most important is that your work will be very hard if you try to define one or more equations for every part you design. What about an aircraft ? It is IMPOSSIBLE.

But, if you use IN CONTEXT EDIT you can define a part using other part, using other part and so on. WITHOUT any calculation.

Say you have a part with a squared hole and other part is an extruded squared.
Say that the hole from first part has certain dimensions.
If you wish to assembly the two parts with a gap then you have (at least) two possibilities:
1) Define the second part using equations (L2 = L1 - 2*Gap) or....
2) Define the second part IN CONTEXT. For that, at assembly level, you can define the sketch for second part as a polygon with edges PARALLEL with the hole edges and at distance = Gap.
After that you need only to modify the dimensions for hole and the second part will be AUTOMATICALLY rebuild as you need without any calculations.

Is hard to explain even in my language. The Chinese say that an picture is equal with a thousands of words.

If you can't understand I'll can see only one solution: TeamViewer.

I expect your answer.

 

[AdamW]

Hi Mihail,

Thankyou for taking the time to explain.

I can understand that for very large assemblies it would be very difficult
ot use equations.

However, for the individual parts within an assembly surely it is ok?

Also, using the 'IN CONTEXT EDIT' feature must perform some kind of
calculation?

What do you mean by TeamViewer?

 

[Mihail]

I say:
Do not use equations if it is not strongly necessary.
And, as usual, equations are not strongly necessary.

Unlike other CAD programs (and fortunately) SW can define parts using other parts or sketches or point of sketches or sketches entities or construction geometry and so on. This avoid a lot of calculations (not all, of course).
So, try to avoid how many calculations you can using SW tools.

Also take a look at CONFIGURATIONS. This is another powerful tool.

If you use IN CONTEXT EDIT you can avoid a lot of calculations. Most of time you don't need any calculations. That depend, of course, of how complicated are your parts and (more) depend of your skills.

Let me know if you need more help.

 

[Mihail]

Sorry, I forget about TeamViewer. Take a look here:
http://www.teamviewer.com/en/index.aspx