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Constraints - New (OnShape) vs. Old (SW and others)

fyorgefyorge Member Posts: 17 PRO
So, when I first started using the OS constraints, I suspect my reaction was similar to most other people's reaction: THIS IS SO HARD TO DO!  I WANT IT BACK THE WAY I'M USED TO.

Now, after having been using it for a while, I really appreciate the OS constraint methodology.  Most of the time.

There are, however, occasions when I really want to be able to have simple constraints back.  I know that most forms of simple constrains are achievable through OS's constraints, but they feel overly complicated with the selection of Mate Connectors.

For example, when I'm building a test fixture, creating the fixture's constraint points using 3x2x1 method (or plane/line/point), I want to be able to constrain things according to how reality will constrain them to make sure that the part fits into the fixture properly.  Yes, I can use the planar constraint to achieve my 3, but there doesn't seem to be an easy way to tell OS that a line should be coincident with a plane, allowing for the part to pivot around the line, while the line stays bound to the plane.  Similarly, Make a point coincident with a plane.  If there are way to do these using the OS constraints, I'd love to know what they are.  If there aren't, I'd love for there to be some kind of "Classic Constraints" mode to be introduced.

At this point, the majority of the time I really like working with the OS method of doing constraints.  One constraint handles everything.  There are cases that this is not enough, though.

Another way of approaching this would be to allow custom control over the constraining of the degrees of freedom.  As I have been thinking about this, the problem is that the default constraints do not allow for constraining only one or two degrees of freedom.  If we had the ability to manually check which of the six degrees of freedom we wanted to constrain, then we would have a much more customizable constraint system that could allow for point (-1) and line (-2) constraints, as well as the existing planar (-3), revolute (-5), slider (-5), cylindrical (-4), etc.

Anyone else have any thoughts on this?


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    fyorgefyorge Member Posts: 17 PRO
    I'm disappointed that there have been no comments about this.  I think that adding in a custom-fasten constraint which would allow you to lock or release each of the 6 degrees of freedom would be a brilliant addition to the constraint system that OS uses.
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    scott_fallscott_fall Member Posts: 5 PRO
    @geoffrey_2 I'll throw my hat in here and agree with you whole-heartedly. OnShape mates don't allow me to mate parts the way that real parts mate together.

    Sometimes I just want parts to sit in space nicely relative to each other, then it's great to use one mate.

    But if I care about seeing how the might "really" move around? Out of luck without significantly extra work.

    For a point-on-a-plane, the work-around I found is to put in a "dummy" part that is basically a surface. You do a planar mate from the dummy to your plane, then a "ball" mate from that dummy part to your point. now your point to plane only has 1 DOF constrained. And similar workarounds with line and plane.

    I mean, that's kinda ridiculous? 

    Also, who's idea was it that I can't reference a plane to create the X/Y plane of a mate connector? This drives me nuts!
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