Sub-assemblies sucks

Hi Gil,

As far as I know this a normal and typical behaviour in SolidWorks since
the first version I know (2000). There is no possiblity in an assembly
with subassemblies to move parts of a subassembly even if these parts
have degrees of freedom.

If you want to move parts in the main assembly then you need to go this
way. An other possible way around would be configurations of the
subassemblies with different positions of the parts...

Greetings

Markus

(email: remove the second "_")

 

Hi,
I have a rather simple assembly with 16 parts, 5 of them are axles which are
parallel to each other.

I wonder if anybody could share his thoughts on my experience with
assemblies and mates - especially when those assemblies include
sub-assemblies.

Here goes my experience:

A. When creating sub-assemblies within assemblies, there are occasions
where solidworks stuck sub-assemblies and parts, although they have still
one way of freedom. this happens with no error message: the sub-assembly is
just fixed in place while attempting free drag (there are no InPlace mates
and no FIX condition. they are also not fully-defined).
Sometimes two or more parts in a sub assembly which are not fully
defined between them appear in the major assembly as a bunch of parts which
are "frozen" or glued together although there are degrees of freedom between
them, and they move only as a whole assembly together.

B. If I reconstruct the assembly which appears in paragraph A, as a
simple assembly with no sub-assemblies (one "layer" hierarchy), then
everything works fine and as expected - peculiar isn't it!


This is the second time this happens me on an assembly with sub-assemblies,
and it forces me to abandon completely the sub-assemblies on my assemblies -
this really sucks when projects starts to be complicated and in relation to
BOM in drawings and who knows what else!

BTW, I use SW2006 SP4.1

Gil

 

Unless I'm misunderstanding your needs, there's flexible subassemblies,
and although they have their issues sometimes, they've been improved in
2006. They've been around since at least SW 2005 from my poor memory.

With these you can still move individual parts of a sub assembly in a
top level assembly.

All you need to do is leave some degrees of freedom in your sub
assembly free, and designate the sub assembly as flexible in the upper
assembly. (Right click the sub assembly in the feature manager,
Component Properties, Solve as, flexible.

Good luck.

--Matt Schroeder

 

As far as I know this a normal and typical behaviour in SolidWorks since
You can move parts of a subassembly within an assembly. You need to go
to the component properties dialog box and change "Solve As" from
"Rigid" to "Flexible".

 

Nothing surprising here, this is basic functionality. Sounds like a
training issue.

 

Matt,
Thanks!!! that's exactly what I wanted! a magic sequence of mouse clicks.
I'm so glad I have this newsgroup for all my solidworks questions.

Regards,
Gil

 

Hi Markus,
Read the reply Matt posted to my question - it might surprise you, as it
helped me a lot!

Regards,
Gil

 

You should feel fortunate...a lot of cad programs don't have this
option.

 

it has been around since 2001 or 01+. it was improved significantly in
05, but it has been there for a while.

 

If Matt is correct, as to the point that this functionality was introduced
in SW2005, then it is not so obvious as some might think.
Regarding the training issue: I guess you are right. (although I still
managed to get CSWP certified before a couple of months, without knowing
this functionality).

Cheers,
Gil

 

Indeed, I am feeling fortunate!

 

"Flexible Assemblies", they are neat but use with caution. Overuse will
get you (or at least your SolidWorks assembly) into trouble.

Ken

 

Which ones??

John H

 

To expand on that.....
One of the key benefits to splitting a large assembly into sub-assemblies is
it makes it much easier for SWX to solve the mates, as it can solve them for
each sub-assy in turn, after which it treats the sub-assys as single
entities - this is why the original poster found they were moving as a
single block.

If you use the "flexible" option, it effectively has to solve the assembly
as if all the components (and hence all their mates) were added to the top
level.
It therefore gets complicated = slower = sometimes falls over.

So I would say it's an invaluable feature at times, but only use it when you
HAVE to.

John H

 

John,
That was a terrific summation of the value of subassemblies in
dynamically moving systems (and issues with flexible subassemblies).
Nice