A few ST Questions 1

[FloridaME1]

I decided to play with ST over the holidays. I agree with many of the posts that this is a completely different way of working. Here are two areas I am struggling with. I have not had training yet. Does anyone have any ideas to help me.

1. Local Symmetry (See image attached) - It seems like ST recognizes symmetry well around the base datum planes, but I have parts that are symmetric around other planes. Read a little documentation on establishing local symmetry (advanced options)- but I cannot get it to work. I looked at all the demos on YouTube, all are perfectly centered on the global CS. (My experience is that that rarely occurs). Can somebody walk me through defining local symmetry to if I move one of the faces the corresponding face will move in a similar manner?

2. Draft Dimensions (See Image) - Rounds and Shells add PMI, but Draft does not. How can I add a draft dimension so I can easily control it? Also, it seems to me that PMI dims become invalid very easily if you delete rounds - this is killing me because I cannot make the modifications I want with the rounds present. I add PMI, fail to edit, delete rounds and have to add PMI all over again.

Please Help.

 

[FloridaME1]

He is the first image

 

[donyoung]

Hi,

here is one solution to the LocalSymmetry problem. Be on
your guard: you have to define this every time you move
that face, local symm. is *not* persitent

HTH

dy

 

[donyoung]

/Edit

a draft is a non-procedural feature thus it can't be controlled
by a parameter like a round. You can either place the Wheel
on one edge of the draft with its primary axis parallel to
that edge and then turn the Wheel's rim or place an angle
dimension on a face that is perpendicular to the draft
to control it. When neither is possible you can only add a new
draft with an angle of 0 deg to nullify the draft. In ST2 (V101)
a draft will become a procedural feature so it can be controlled
by the once defined angle.

There is no need to place a PMI dim to a round to control it
just select the round and adjust the dimension that pops up.
Caution: placing a round on an edge with an radius equal
to the thickness of the part makes the round unmodifiable
and undeletable. Sample: a plate 4mm thick rounded along
one edge with 4mm -- with 3.999 it will remain modifiable ...

dy

 

[FloridaME1]

Thanks donyoung

I was picking both faces then trying to establish the local symmetry. You only have to pick one face and ST will find the other. It is too bad the relationship is not persistant.

Still plugging away. Thanks

 

[donyoung]

Hi,

to define the plane you can also select PlaneNormaltoCurve
then select the edge and select from the QuickBar --> Midpoint
and fix the plane to the midpoint of the edge.
The elements found under Advanced will be created for the
current manipulation only. So when doing anything you have
to check whether the found elments are only those wanted ...

IMHO not everything works as it should be -- SyncT seems to be
a bit half baked ...

dy

 

[donyoung]

/forgotten:

when you dimension the height *before* placing the
round the dim will not become invalid -- don't ask
me why it works this way round

dy

 

[beachcomber]

As I don't have ST could one of you guys answer a question for me?
In the first image you have a conical cylinder.
Now, if you had created that with say a 2" bottom diameter and 1" top diameter, then applied the top fillet, how would you then change the top diameter to say 1.5" ?

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[donyoung]

BC,

at the moment there is only one solution: delete the fillet
change the top diameter and redo the fillet.
BTW: in case the top has been dimensioned before applying
the fillet it will become detached when the fillet is applied
When you leave it there and delete the fillet SE will
automatically reattach the dimension.

dy

 

[FloridaME1]

I agree with donyoung. I had to delete the round. I tried adding diameter dimensions to the tangent edge of round (where the round meets the cylinder.) But could not change the diameter.

To me it seems like ST requires many 3D relationships to get the model to update in a predictable manner. (PMI, relates, and live rules) I am not sure if I need more or less relationships than traditional modeling. But, the sketch relationships that help drive a traditional model seem easier to understand and more poweful (equal relationship, sketch symmetry, etc).

The history based approach just seems to allow you to eat the elephant one bite at a time - and for me that is easier.

I wonder if the Solid Edge guys are going to enhance the traditional modeling methods or just keep moving down the ST road. I think ST is years away of being ready for prime time.

On a related note, my testing finds that symmetry and pattern recognition is limited on imported geometry. (Symmetry is limited because it is rare to get an imported model centered on the datum planes)

 

[donyoung]

[cite]
I wonder if the Solid Edge guys are going to enhance the traditional modeling methods or just keep moving down the ST road.
[/cite]

I fear the latter ...

[cite]
I think ST is years away of being ready for prime time.
[/cite]

I fully agree with that. Maybe with ST4 (V104) or later I
might become usable.

dy

 

[donyoung]

/Edit

oops! I'm still usable so it should read '... it might become ..'

 

[Incinerman]

I have imported some parts as STEP files from my previous CAD (Alibre) into SEwST, and it was suggested by support that these are best modified using ST. Trouble is, rounds and fillets seem to behave entirely differently.

I really can't seem to get to grips with ST - it isn't intuitive to me in the least, and every time I see the amount of hours I've wasted playing with it I get to feel it's more loathsome.

Parametric sketches and a history tree? Er, what's not to like?