Sketcher constraints - No equal?

[fighterpilot]

In sketcher is it possible to set an entity to be the same length as another dimensioned entity by using a constraint such as "equal length"? Best I can find is to dimension both then use a formula to relate one equal to the other.

V5R18

--
Fighter Pilot
Manufacturing Engineer

 

[jackk]

You can use a Formula, or you can use Equivalent Dimensions

 

[Azrael]

Use the formula short cut, make one dimension and set it then make the second one but when setting the value input "=" and then pick the first dimension in the graphic window.

 

[aardvarkdw]

This is the single most frustrating thing for me about going from Inventor to CATIA.

David

 

[fighterpilot]

Throw Pro/E and UG in that as well. Both offer the "equal" constraint.

--
Fighter Pilot
Manufacturing Engineer

 

[weavedreamer]

The 'EquivalentDimensions' feature allows you to set as many dimensions equal to each other, then changing any one of those dimensions will change all of them. This feather is located in the 'Knowledge' toolbar.

 

[fighterpilot]

weavedreamer,

Understand that. However, I was looking for a way where I didn't have to place dimensions on everything. Pro/E and UG will let you just pick then entities and set them all equal to an entity which has a dimension.




--
Fighter Pilot
Manufacturing Engineer

 

[Azrael]

This will not be connected but you can set up one dimension with wanted values and the copy it (ctrl+c) then pick another line and paste (ctrl+v). It will copy and set previous value.

 

[aardvarkdw]

Yeah, but that still means that you have dimensions all over your sketch and that makes it difficult to read sometimes. I would really like to just dimension one entity and then place a geometrical constraint on the others that makes them equal to the first one. You change one dimension and they all change, but without having to go through the extra five or so steps of creating dims for them all.

David

 

[2gevad]

Any time you are in sketcher you can double click the constraint to edit it, clear the entry field and type in = then select the constraint you want the value equal to. This builds a relationship between the constraints.

 

[aardvarkdw]

again, that still clutters the sketch with extra dims. I would rather have a sketch that clearly shows my design intent, i.e. that several features are equal not that thy just happen to have the same value at this point in the design. Think of a clear and concise drawing. It will have one dimension and will say that it applies to (X)places.

David

 

[Albigger]

The only thing I can think is if your sketch is symmetric you can use the symmetry or mirror function to generate geometry and keep sizes constrained to the original (and it will clearly show with a mirror constraint icon).

 

[aardvarkdw]

A good example of what I would like to see is this. I have 32 circles in a sketch, they are all the same size but are not in a cohesive pattern (not rectangular or circular). Rather than have 32 dimensions that I have to individually link and that will clutter my screen, I can dimension one, place equal constraints between the others and the one that is dim'd and they all adjust by changing the one dimension.

One dimension, and 31 geometric constraints. Easy to determine which feature has the controlling dimension, and little chance of confusion when someone else goes to edit my part.

David

 

[PeterGuy]

Why are you not using user defined pattern for this??

 

[aardvarkdw]

Because if I did need to change one differently I would need to then create it from scratch but that is beside the point (which yours is a good one by the way. I would most likely use a user defined pattern in the case I described).

How about a complex shape that has several lines with equal lengths?

The point is that this is a feature that most other programs have, and to do the same thing in CATIA requires twice as many steps and is messy when finished.

David

 

[Albigger]

I don't know of anyway of doing that within a sketch (and yes that would be a handy feature).

If it was me I may consider drawing the controlling circle and using a userpattern for the others. Not as robust as having it all in one sketch but easier than creating all the dimensions and relations.

 

[Albigger]

Oops, Peter beat me to it.

And for what its worth, if you have an oddball, you can always un-select an instance of the userpattern, and sketch your profile at that instance. It becomes even easier if you use a positioned sketch and copy/paste.

 

[PeterGuy]

Alternatively you could make one of the points in the instance sketch into an output feature, keeping its positional definition in the positioning sketch but seperating it out from the pattern, for you to create the oddball instance on.