CAD/CAM discussion forum > 3D CAD/CAM > Sketcher Colinear Constraint

Sketcher Colinear Constraint

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John

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Registered: 2004-10-14

Message 1 of 10

 Sketcher Colinear Constraint
14-04-2005 03:58 . pm | View his/her posts only
Is there a way to manually add a colinear constraint? I've searched high and low, but I can't find a command that inserts a colinear constraint. They only way I can seem to add one is using the Auto Constrian command.

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ChrisWard2k2

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Registered: 2011-11-22

Message 2 of 10

14-04-2005 08:09 . pm | View his/her posts only
Hi John

Depends on what constraint you actually mean - one would normally be using the "hold points vertical" or "hold points horizontal" X and Y constraints for this purpose, which you find in the constraint menu whose first icon is the Anchor (X and Y) constraint.

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John

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Registered: 2004-10-14

Message 3 of 10

14-04-2005 08:52 . pm | View his/her posts only
There is a constraint icon I see sometimes, which is a straight line with a small circle in the middle of the line. When I do and Inquire on this constraint, it's labeled a Coliniear constraint. There are times when I want to constain a line to be colinear with a reference line using this constraint, but I can't figure out how to add this constraint directly. The only way I've been able to add it is by adding other constraints, then using the Auto Constrain command.

-- John

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ChrisWard2k2

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Registered: 2011-11-22

Message 4 of 10

14-04-2005 09:50 . pm | View his/her posts only
Hi again John

That one is the point-to-line constraint, 4th icon down, then it is the 2nd icon on the fly-out sub menu.

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Kevin

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Registered: 2004-4-26

Message 5 of 10

15-04-2005 06:21 . am | View his/her posts only
I agree with John. A co-linear constraint is a very useful thing indeed. VX seems to focus only on points, but from a user's perspective when designing it would easier to select a line to constrain to a line. Maybe a case for tidying up the interface a bit?

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Steve

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Registered: 2004-10-9

Message 6 of 10

15-04-2005 09:45 . am | View his/her posts only
I agree with John and 3Dmonkey.

IMHO, VX's weak point(design wise) is the sketcher.

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ChrisWard2k2

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Registered: 2011-11-22

Message 7 of 10

15-04-2005 02:53 . pm | View his/her posts only
Hi All

When using this constraint, you do not need to have a point entity in place, you can select just the line, the line's critical point is used.

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Kevin

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Registered: 2004-4-26

Message 8 of 10

16-04-2005 01:27 . pm | View his/her posts only
Its a funny one though Chris.

As a user I'd like to see some better explanations of the constraint conditions during application, and less confusion over the way they work. As we said above the co-linear constraint in other systems is what is says it is. It makes one line follow the line of another reference line. Whether this is done via points or not is irrelevant to the end user and the "design intent" (a good SolidWorks phrase that) is to make lines follow lines.

In VX you can achieve the same if you use the Draw command to create sketches.In this command if you draw, say, an angled line, a horizontal thena vertical then another angled line you can make the second angled line "tangential" to the first and it picks up a parallel cosntraint condition. If you then dimension one angled line end to the horizontal reference when you change the size both angled lines move in unison - like a co-linear constraint in fact. But its not. 'Cos you can easily break this by dimensioning the other end!

The really BIG issue with VX constraints - to me - is that you can't drag the entities around and maintain the end point constraints - they break. You have to apply dimensions every time. As a designer this is tedious. I want to pick a line or curve and drag it - not have to keep fiddling with dimension values to get what I need.

If the development teams needs a focus to make the app truly great then this is the area I think they need to focus on - the building blocks. Thats why SolidWorks etc are so popular. The D-Cubed sketcher may not be the best or the fastest but it is very flexible and user friendly. In my opinion VX's sketcher has a way to go in interface terms.

The VX sketcher may well be fast and efficient etc etc but if it takes me 1 hr to apply a simple set of constraints then it doesn't make me very efficient :-)

Lets have a vote for the best 2D sketching interface on the market! Then get VX to copy (sorry, improve) it! So who cares what happens "under the hood" its whats in my windscreen that matters to me, and if there is a great huge mud splodge (technical term that) and my wipers are down then what good is my 400 BHP V12 engine?

Sorry if I'm a bit "passionate" about this but it is critical to my work and I've just renewed maintenance on VX so I've got a vested interest!

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Kevin

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Registered: 2004-4-26

Message 9 of 10

16-04-2005 01:34 . pm | View his/her posts only
My vote for best 2D sketcher BTW is SolidEdge v17 not SolidWorks (though I've yet to test the latest version which does have improvements).

Ashlar-Vellum Cobalt has the best curve creation interface - its just they don't really have very reliable 2D parametric (dimension driven) constraints - but they do have the easiest curve creation and editing tools I have used - in 2D and 3D.

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John

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Registered: 2004-10-14

Message 10 of 10

16-04-2005 02:51 . pm | View his/her posts only
I completely agree with 3Dmonkey about the sketcher and constraints. I spend a lot of time trying to get the constraints right. There are times when I simply want to drag a line and have the other lines that are "attached" to it change length so they remain attached at the same point. However, as 3Dmonkey pointed out, I have to instead apply dimension constraints and then vary the dimensions until I get what I'm looking for.
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