Smart Trim Command

[whiteskulleton]

I propose that trimming geometry in a sketch preserves the behavior of the parent geometry. Looking at the picture below, if you trim the 2 edges of the 1 inch circle, the dimension is deleted and the 2 arcs are now unrelated. Sometimes this is exactly what you want. Therefore a new trim command should be added or you have a checkbox that says “Preserve sketch constraints and dimensions” or something similar to that. This trim command makes the new geometry behave like the old geometry while also keeping the dimensions. This saves time and makes the operator more efficient by not having to apply the constraints again.

Note that an equals constraint was added to the 2 arcs to maintain their behavior.

[jtylerbc]

I think this is a great idea, and would save me a lot of grief.

In addition to your suggestion for arcs, I would propose also that it automatically add colinear constraints for cases where the middle of a line has been trimmed out.

[whiteskulleton]

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jtylerbc wrote:

I think this is a great idea, and would save me a lot of grief.

In addition to your suggestion for arcs, I would propose also that it automatically add colinear constraints for cases where the middle of a line has been trimmed out.

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Of course. I was thinking that any geometry you trim, whether it be a line or a polygon, would maintain the behavior of what it once was. The trim command does do that already but it only works if you only trim one part of the geometry. If you cut out 2 sections of the constrained geometry it all starts to fall apart.

It would also be nice if it would work for geometry that you offset.

[niksasa]

I doubt very much that it was possible to implement. Name one program where this is possible?

[Pete_Mort]

Moving to Inventor having used Solidworks for years this is one area where I recognise that Inventor is lacking, both myself and my team members have struggled with the Inventor trim functionality during the 4 months that we've been using it. SolidWorks by default applies constaints on trim to maintain entity relationships and does not delete dimensions allowing the user to progress following a trim command rather than stopping and putting some constraints back in as we have to do with inventor.

Additionally the trim behaviour in Inventor seems inconsistent, some times when trimming lines coincident constraints aren't added to the endpoint. This is subsequently picked up when failing to extrude because its impossible to select a profile, close inspection of the skecth shows the missing coincident constraint.

http://autode.sk/1Ni0Gty

[dan_szymanski]

Idea added to backlog for future consideration [12617]. Thanks!

[AlexZW28B]

I really hope that this would be implemented - using 2020 this is still a big issue/fail in my opinion. A lot of time is wasted having to re-do things I already constrained - considering that entities are still existent, the relations should also remain in place - this is a huge pet peeve of mine. And yes SWx is much MUCH more stable with sketches in general than Inventor is... 

[gregory_nickol]

It shouldn't be hard to implement this and here's why:

On a line, you start with a line defined by two points at x1,y1;x2,y2 (z could be there to for a 3D sketch but that's not important to the point). When you trim a line, there's only a couple possibilities, you're either:

• moving your x2,y2, or creating an entirely new line when trimming from the end
• on trimming a middle section out you're effectively changing the existing line to x1,y1;x3,y3 (or it's a new line and the original is deleted) and making a new line x4,y4;x2,y2.

Based on this the trim command must already know if it needs to "create" a new line, so if the trim operation WOULD create a new line, it should be able to automatically apply the collinear constraint between the original and newly created line. This same concept can of course be directly applied to circles, arcs, and ellipses.