Relations

Can anyone share a the quickest method of deleting all relations in an
entire model?

In my position, I seem to have to continually remove features to get some
features I want, but the relations sometimes are a real pain because it
won't let you remove features.

 

Bill,

I would suggest that you're going a bit overboard. At the risk of
sounding rigidly absolute, deleting all sketch relations in a model
strikes me as a really bad idea. There is no tool in SolidWorks that
allows you to do that, unless you wrote a macro to do it. You can delete
all the relations and dimensions in a single feature using the Display
Delete Relations tool.

A better approach, from my way of thinking, is to get more comfortable
with building with a "design for change" concept. If you delete all
relations, the very next change you make, you're going to wish you had
them back.

There are many examples that can be made, but one of the most frequent
is when folks put fillets on early in the model, then sketch relations
in subsequent features go to the edges of the fillets. Now you're
trapped. Cosmetic fillets are better off going at the end of the tree.
Non-cosmetic fillets have to go where they have to go, but consider
making sketch relations to the sketch that made the edge (for extruded
features) rather than the edge itself.

Modeling this way takes a bit of discipline. It's not as fast as
clicking on a face, hitting convert entities and extruding. The concept
can be carried out to its theoretical extreme where a skeleton of the
part is made from sketches, planes and axes, and the solid features have
no relation to one another, only relations to the origin, sketches,
planes and axes. This is an extremely conservative approach, but also
valid way of doing things. If reliability through changes is your main
concern, the more conservative you are, the better. If sheer initial
modeling speed is the main concern, then "fast and loose" use of all the
design automation tools is what gets you there.

Nobody's going to tell you how to model, but different techniques are
good for different goals.

 

Matt said a lot of things I have learned the hard way (and fortunately
don't need to relearn too often). The acid test of a CAD designer
isn't what he can model, it's what he can change.

I spend a fair amount of time laying down foundation or framework
before any solid features are made. When I designed hinges, all parts
had skestches, planes, and axes indicating pivots, mounting surfaces,
and overall profile before the first soli feature was made.

Once your layout/skeleton features are in place, refer to them whenever
possible. i.e. Don't use a face edge when it coincides with a layout
line; use the layout line. this way you don't have references stacked
10 deep that unravel when one feature changes.

 

Hi Matt,

Thanks for the advice. I am an applications engineer for a CAD/CAM company.
Hence I am not really doing much as far as creating models. What usually
happens to me is, I get a model from a customer who wants advice on how to
use our software to machine a specific part. Ocasionally, to get the tool
path I want use, I have to modify the model or more often delete some
features. What i keep running into is the feature I need to delete is
releated to something else and it won't let me delete it. At this time, I
also have no formal training in solidworks. I will look at the Display
Delete Relations Tool as it sounds like that may help me.

 

Bill,

Deleting relations, especially in a sketch can cause performance
problems as well as leaving the model totaly free to move around.

 

Bill,

Cleaning up a part so that it can be machined or have other processes
applied is a bit of an art. The tools of the trade are suppression,
roll back and reordering. There is a parent/child tool that can be
invoked by right mouse clicking on a feature. This will show how a part
is modeled in terms of dependencies. You can do various tricks also if
you have the Utilities addin like search for features of a certain
size. You can use a surface to remove features also. Since we don't
know what process you are preparing the model for I can't be more
specific.

You might also consider exporting the part into a parasolid and
reimporting it. Then use various cuts to remove material you don't need

 

Do some experiments with dumb solids. Export your part as a parasolid,
re-import, and see what you can do with it.

Things to try:
--Delete Face
--Replace Face
--Move Face
--"Drill-and-Plug": cut out a region that doesn't work for you and
replace with your own geometry. Sometimes helps to save original faces
first using offset surfaces to use as reference for your new geometry.
Use "Delete Bodies" to clean up extra surface bodies afterward.