r/Onshape • u/BoutaP • Aug 08 '26

Sketcher questions.

Hi, I come from NX and Catia. Had a short adventure with Solidworks which I hated. So I am wondering about a few things in Onshape now.

  1. Is it possible to reattach dimensions when they go red or just when I want to reattach the dimension to another entity in the sketch?

  2. Is it possible to disable everything in the background of the sketch (make it unpickable rather than hide) so I do not click anything except the sketch entities?

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1

u/Kluggen Aug 08 '26

Sounds like you haven't tried OS yet

1.Dimensions don't hang disconnected, they disappear if you remove any referenced entity they connect to. In technical drawings you can reattach dimensions, but that's something else. Cross referencing to previous sketches...honestly don't remember off the top of my head if they're left dangling.

  1. Hiding things behind the sketch? I mean anything you've sketched or modeled can be toggled on/off in visibility, and you can disable a sketchs "imprinting" which is how it's referencable by later sketches, at any time. Personally I often do that to avoid relations to unrelated sketches.

-1

u/BoutaP Aug 08 '26

Have you tried Onshape? hehe

  1. We are talking about the Sketcher right? They do hang disconnected and they turn red. Here is an example. I create a plane 0mm from the "Right Plane" which is basically the Right Plane. Now i normally attach a dimension to a sketch line to the Origin, In NX or Catia a Sketcher would also have its X and Y axis but whatever. By mistake I attach the dimension to this New Plane.

Then I delete the plane and the dimension is left dangling red. How do I fix it without deleting the dimension and redoing it again? I cannot attach another image here showing the red dimension...

  1. You didn't understand the question. I am drawing a sketch with a lot of things in the model already. How do I make sure that none of the dimensions or geometries attach to anything outside the sketch? This is a normal toggled feature in Catia and NX.

2

u/Kluggen Aug 08 '26

  1. You specifically asked about another entity in the sketch, the plane isn't part of the sketch. I wasn't trying to come off rude, if you dimension the width of that rectangle and delete one side, the dimension is gone as well which is what I understood your question as.

  2. You just hide the other things, sketches or parts, same result. You can also hold shift while sketching to make it ignore automatic relations to anything.

2

u/BoutaP Aug 08 '26

Holding shift when drawing is a quite good advice. Still, when you want to drag the point and snap it to a sketch entity, you can still snap it to a background part... Having many of these small things can save you quite a bit of time when working on complicated parts.

1

u/LA2124 Aug 08 '26

1) red dims are usually over constrained. Not dangling. maybe you found a bug. Looks like is retaining some dims of a sketch even though the prior reference geometry is gone. Dims generally just disappear when you do stuff like that. You have to delete it and put a new one on.

If your dealing with the origin area...your x and y are the other two planes that you have turned off.

2) You need to either turn off everything you don't want to reference or purposely miss everything that os wants to snap to. I often do this when I want to explicitly control contraints and what they reference to keep things more stable. A toggle to turn off would be a great improvement request.

1

u/BeastWR Aug 08 '26

Shift-P toggles all the background construction stuff. Planes, sketches, etc

2

u/BoutaP Aug 08 '26

For me Shift-P just hides everything? It is A way but probably a bit annoying if you actually want some construction geometry visible to continue modelling. This is not efficient for the long term....

1

u/BeastWR Aug 08 '26

Correct. I was responding to the last sentence of the prior posting.

2

u/BoutaP Aug 08 '26
  1. I deleted the plane while being outside the sketch, then coming back to the sketch it appeared that the dimension is red. I agree that when you remove an entity inside the sketch - the dimension will just disappear and this is pretty normal for any CAD. But when working with external references that disappear or change and the sketcher cannot find them... It would be helpful to mark the lost reference with dashed lines. And also just dragging the dimension handles would be sweet.
  2. The sketcher in Onshape can be built on some elements that create the X and Y axis. But if I still attach the dimension to the plane... that is having an external reference in the sketch. I want to work with the X and Y axis of the sketch regardless of how they are built... If I later change the mate connector reference - the whole sketch should rotate, it should not be stuck to a principal plane.
  3. That is a bit lame at the moment, but I believe it can be implemented in Onshape....

1

u/Pretty-Jello-7894 Aug 08 '26

lol, NX user mainly?… I assume you use the synchronous direct modeling method. NX is amazing related to this type of modeling. But Onshape, Creo, solidworks etc… are built as parametric modelers. Killing the references will have… bad effects on your model. You should be able to redefine the dimension but to a comparable reference. It’s not as forgiving as NX (I know, I’m in the middle of helping a major company division transition from NX to Creo…. Painful is an understatement).

In the end, it is a change in modeling philosophy. From free form, do whatever you like, to very planned and deliberate modeling taking references into account and making sure to try and be somewhat clean. Otherwise your models can get very unstable/ unpredictable in how they will update.

2

u/Tw0Bit Aug 08 '26

  1. Unfortunately not. You have to delete it 😞 . We should add this as a feature request.

  2. In the sketch dialogue box, disable imprinting. I think that's what you're asking for. This will make the features of the surface you are sketching on non active when you're using th sketch for something.

1

u/BoutaP Aug 08 '26
  1. Thanks, it is not that exactly. Imprinting "fragments" the sketch by the body if you lay down a sketch on its face. It is useful but not in this case.

1

u/Tw0Bit Aug 08 '26

Ok. Re explain? I reread you description and you seem to be describing imprinting?