Offset line or rectangle...

[csusie]

To be honest with you there isnt much need to be able to do it. You havent proved to me that there is a need for it yet. So why is it you need to do this?

 

[ledo]

I don't have hidden agenda and i don't need these function for any project.


I was yust learning and wanted to do something straight from my head. In the process i planed to use offset. But later on i discovered the story behind offset and sketcher geometry.


Iused some of CAD tools in the past and i don't know if any gave me troubles with offset-ing. I could always offset everything and enywhere. its such a basic function.


Where could it be usefull? In any sketch (section) that we use "constant thicknes" for example?


There realy isn't any problem. It always can be done with 2 sketches. But its funny if we wouldn't need offset as you suggest why is then offset option in second sketch (model geometry if i understand corectly) when we use a edge from first sketch?


So u see to be able to use offset or not is not realy a real question. Offset feature is included. So it must be valuable in some time.


I yust wondered why its not included in sketcher geometry. There is a reason for it i'm sure.

 

[csusie]

"Where could it be usefull? In any sketch (section) that we use "constant thicknes" for example? "


You use different functionality to do this. There is no need to sketch the inside and the outside profile you sketch one or the other and use the "thin" option.


Don't live by the rules of your old cad system, this system is different, not wrong but different. So you need to learn different ways to do a similar thing.

 

[ledo]

...if we wouldn't need offset as you suggest why is then offset option in second sketch (model geometry if i understand corectly) when we use a edge from first sketch?...

 

[kdem]

For a constant thickness try using the thicken icon if the feature has it. The sketch will contain the shape. You specify whether the material should be inside, outside, or symmetric about the sketch. Extrude, revolve, and variable section sweep have the icon. For others you may find thickness in a dialog box such as the Insert>Sweep>Thin Protrusion.

 

[jeff4136]

> I used some of CAD tools in the past ...
> its such a basic function. ...
> I yust wondered why its not included in sketcher geometry.
> There is a reason for it i'm sure.


It is a basic function. You'd have to ask PTC why.
I'd guess ...
_ Non parametric equivalents, i.e. Acad and Rhino don't really count
as they don't have to deal with history or variational constraint
solvers.
_ Parametric programs you may have used probably use D-Cubed's 2DDCM
(count SW, SE, IV among these). PTC has developed their own, I believe
(a good thing in my opinion, I like it).

 

[michael3130]

"Where could it be usefull? In any sketch (section) that we use "constant thicknes" for example? "


You use different functionality to do this. There is no need to sketch the inside and the outside profile you sketch one or the other and use the "thin" option.


Don't live by the rules of your old cad system, this system is different, not wrong but different. So you need to learn different ways to do a similar thing.

Csusie, I agree with your last statement. I have found in the past people coming from other CAD systems try to replicate what they have learnt and end up in difficulties such as Ledo has shown here. However, I have had instances where the offset command would be useful. Some of the sketches I have done could not be extruded as thin features as there were other areas of the sketch that were not of constant thickness. Saying that, SW has the offset command in sketch but I avoid using it as it always seems to give me problems. I prefer to manually offset the lines if I have to and have full control over my sketch.

 

[ledo]

...Saying that, SW has the offset command in sketch but I avoid using it as it always seems to give me problems...

Yes as i said there must be a reason why proe doesn't use it in sketch geometry.


Iagree. Using proe takes different aproach sometimes andcould be hard for beginers wich used otherCAD system beafore. I find things sometimes dificult but not soo much for mayority of things i did so far.


But it would be wrong to say that offset isn't sometimes the right approach in proe beacose proe uses it. Yust not in sketch geometry.






Edited by: ledo

 

[ledo]

Ok here is one example i think using offset is a fastest and most easy solution. And not wrong to do it like that:


It uses at least (3) Edit: 2sketches and one extrude to do these.


First with 3sketcheswe make ONE section for extrude:


Sketch one:





Sketch 2:


We use edge fromsketch one and offset it. We make lines that"closes" these 2 curves with dimesnisons tohorizontal center line.





Sketch 3:


We make section for extrude: Edit: i can trim it in section 2 so section 3 is redundant.





Extrude1:


We get extruded solid.



Edited by: ledo

 

[jaypogi]

To be honest, while reading this topic, i don't see any point that there's a need to offset any shape while in skecher? offset functionality of proe can only be created based on existing feature.


By the way based in your example you can make your protrusion in just two sketches..to this, while in your sketch 2 just trim your sketch to create a close section, so there's no need to createthe third sketchedsection for protrusion.
Edited by: jaypogi

 

[ledo]

Now we have contol over everything with wery litle dimensions:


Thicknes:





And the angle of left and right solid "closing".

 

[ledo]

To be honest, while reading this topic, i don't see any point that there's a need to offset any shape while in skecher? offset functionality of proe can only be created based on existing feature.

We would be able to use only 2 sketches if offset would work in sketcher. If we would be able to create model geometry right in the first sketcher then we would need to use only one sketch.


So if you don't see the point? The point is it would be faster, simple andthe right aproach.


So if proe does it different it doesnt mean is the bestway orthere is only one way that is right and that is proe way?

 

[ledo]

But there is something for further discussion i found more interesting.


Why is offset in proe limited? On the uper example i could only offset the curve to cca 56 units. It wouldn't offset more. Why is that?

 

[ledo]

By the way based in your example you can make your protrusion in just two sketches..to this, while in your sketch 2 just trim your sketch to create a close section, so there's no need to createthe third sketchedsection for protrusion.

Yes you are right. I could trim in section two. So section three is redundant.





Edit:


So the bottom line:


Is offset realy not the best option in some cases? What approach would be better to do my example?


Logic why offset isn't presented in sketcher geometry is starting to kick in. Probably it has to do with the fact that we would still need to make second sketch to make model geometry. (use edges and trim it).


We can't trim for example in sketcher. Or can we?So yust offset wouldn't do much good.


But i still have the question why in my example offset in model geometry only worked in range -4 to 56 units. (inches) Does it have something to do with stuff like tangency...?
Edited by: ledo

 

[jaypogi]

The only thing we can do for now is wait for PTC to add this functionality in future release of proe or suggest this to them if they will listen? for now, all we can do isfollow everything how proe works..this is the reason why i don't see any point in this topic, if we would like some enhancement in proe we need to contact PTC or include everything in the wish list hoping that they are reading everything.
Edited by: jaypogi

 

[ledo]

So bottom line:


Model geometry and sketcher geometry with proe are too different to work together in one sketch? These kicked in in my head in these discussion. So is there really no point in founding that out for somebody that doesn't know it all ready?


I think is good to know. And I am glad to have these understanding now.





P.S. But feel free to explain to me i think wrong. I will be happy to change my knowladge to more correct one!
Edited by: ledo

 

[jaypogi]

yes, offset tool was programmed based on model geometry, not for sketcher geometry. If PTC will include this enhancement in the future release of proe, it will be a good tool for faster part creation.

 

[Asho Pulsar]

Proe is bit practical in all the things...learning proe isn't the easy way, some practical knowledge is also required.


Let me take an example, might be this would the logic. Just imagine,


Take one sheet and sketch a line or curve(line/curve is non-geometry)on it using pen/pencil. Just think howcan you create a parallel line/curve without intersecting thealready drawn line/curve.


For that any measuring instruments is must to create a parallel line/curve right. Or else keep one measuring scale on oneside touches the drawn lineand draw the line on the other side of the scale which is parallel to the drawn line. Thats make the sense of how the line is offset from the line.


So the bottom line is you need one model geometry (Measuring scale in that example) to offset the line/curve.


One more thing, no other mechanical softwarethinks practical feasibility than proe as i known till now.

 

[kdem]

In your example the reason there are limits is that you are getting to a point where the geometry you are offsetting can't be created. Here are some pictures of what is happening in the areas of curvature as you offset the spline. The red curve is the original sketched curve and the others are offset. The curves fathest away from the red one are close to the limits where the geometry can't be created.