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Flip command on mate axis

Flip command on mate axis

When mating an axis from one part to another it often mates the wrong way you than have to cancel out rotate the part the remate it. This very time consuming and requires a lot of clicking. All you need is a flip option. 7.JPG

The flush/mate button flips the constraint orientation, however, in the example you've shown, you'd be better off using an insert constraint... Have you tested out 'joints' yet? What do you make of those?

The Flush/Mate buttons can't flip the orientation on a centerline (axis) mate.  Clicking Flush will deselect the centerlines and won't let you repick them. 


An Insert constraint might be more appropriate in the particular example the OP posted, but I have seen many cases where this feature would have been very helpful - especially cases where the centerline needs to be mated to a hole in one part, then a face is mated to another part.  I'm a big fan of the Insert constraint, but I would still have a lot of use for a flip button here.


An automated preview (as in modeling when doing extrude/cut) could be helpful to determine whether a check in the "flip" is required or not.


Do you not have to put another constraint on this? Or is this to move up and down in the hole?


 If not I agree insert should have been used and if not the other constraint needed would be my flip and that is no extra clicks besides the ones you would need.





I'm with jletcher on this one.  Most of the time you would need another constraint to remove the degree of freedom to translate along the axis.  Adding this second constraint correctly will flip the part anyway.


Also, you don't have to cancel the constraint in order to flip the part.  If it assumes the wrong direction, just complete the constraint, then rotate the part using the Free Rotate command (see below, or press G on the keyboard).  Once you rotate the part to somewhere close to the orientation you want, just update the assembly (or continue with additional constraints) and it will resolve the constraint to the correct orientation (unless you have other constraints that won't allow this).


Free Rotate Command.PNG


Cameron Whetten
Inventor 2014


You don't have to cancel out.  You apply the constraint and then use "free rotate" (hotkey "g") and flip it over.  Otherwise you're going to need two independent constraints.


I think it is better to use the second constraint (I usually use an angle constraint).  Otherwise, you can get unpredictable flips when moving and constraining other parts.


If you're constraining it in position.  If you were going to both lock down the axial movement as well, you should use the Insert constraint.


Well, of course it's best to use a second constraint in the final assembly, but I want this option for when Inventor faces the part opposite to the direction that I want when I'm initially applying the constraint.

This would also be useful when editing existing assemblies. I Googled my way to this topic because I needed to modify an existing cylindrical vacuum chamber by swivelling one of the ports 45°. The final weldment had a tube assembly constrained axially to the port and tangentially to the inside surface of the chamber, and when I changed the axial constraint to the new hole, the tube assembly snapped to the wrong side. For want of an axis flip command (or, for that matter, an Insert command that recognizes holes in curved surfaces), I had to waste a lot of time suppressing other constraints, dragging the assembly into position, grounding part of it to spin an elbow, ungrounding that part, turning constraints back on one by one, and then complaining about it on the internet.


The Insert and Tangent constraints have axis flip and inside/outside toggle capability; it seems reasonable enough for Mate Axis to have the same option.


Totally agree.  This is basic functionality, and has been in SolidWorks for years.


The guys who have mentioned that you need another constraint are correct, otherwise the position is underdefined.  However, quite often the part ends up aligning itself the opposite way to the way you expect, and it's annoying to have to move around to try and find the face you want, when you could have simply clicked 'flip.'  Secondly, I find that quite often the face you want to select is hidden within other geometry.  You therefore have to move/rotate the part yourself before you can add that all important second mate.  Again, this wouldn't be an issue if the flip mate alignment existed for axial relationships.

Status changed to: Accepted

Accepted idea [404 & 3487]. Thanks!


I agree that this would be very handy. This is one common situation when a simple flip option would be very useful:


Axis mate flip.jpg


When constraining say a shaft in a hole, would be great to have a flip option. I understand that a manual rotate, or applying a second constraint enables the flip, but nevertheless it would be nice to have flip as and right mouse button option.


Ah yes, thank you for letting me know. It didn't come up on my search before I posted my OP. I'd delete mine if I knew how!


There's something fundamentally wrong about the Mate constraint for axes. @PaulMunford was actually on precisely the right track in saying "The flush/mate button flips the constraint orientation". It's not how Inventor does behave for axes, but it's how it should. Here's why: Every plane has a vector associated with it. That's why toggling between "Mate" and "Flush" flips the orientation when constraining faces. "Mate" makes the vectors point in the opposite direction, while "Flush" makes them point in the same direction. Extending that logic... every axis is a vector as well! So really, the Mate and Flush options should work the same way when constraining axes.


But for whatever reason Autodesk chose to abandon consistency and logic, and chose for only the Mate option to work with Axes, and for it to have no control over their orientation. This was probably to allow more flexibility when using the Mate constraint, so that it doesn't force a certain orientation if the user doesn't want it to. However, by that logic, we should also have that same option of flexibility when mating faces, and in fact I would love to have that flexibility. I would love the option to simply make two faces parallel and leave their orientation open to be manipulated based on other constraints--just like I can do when mating axes. This would dramatically reduce the occasions that I have to fix sick constraints when changing something in an assembly.


All of that to say, it would be very nice to have the best of both words combined into consistent mate options. The ideal solution would be to have three Mate constraint options: Mate (which forces vectors to oppose each other), Flush (which forces vectors to align), and a third option which leaves the vectors free to orient in either direction. This would give us as much or as little control as we want when constraining faces or axes together.




Kudos for the analysis of Droam!

So many times I thought of the same thing. It would make the action of constraining and fixing constraints so much more smooth! Make three constrains for both plane and axis constraints:

- Mate

- Flush

- Free direction


I've given this a little more thought, and I think this would be the most logical system and nomenclature:


Mate Types.png


So, instead of having a "Mate" Mate and Flush Mate, we now have an Opposing Mate, an Aligned Mate, and an Undirected Mate.


The Undirected Mate could potentially be called a Free Mate instead, but to me that doesn't make much sense because we are constraining it. And if it's "constrained" then it can't be "free". "Undirected" makes the most sense because, while it is constrained, the constraint doesn't control the direction.


The words "Opposing", "Aligned", and "Undirected" make sense for both planes and axes, especially when you consider that each plane has a vector associated with it, which is implied and made fairly intuitive thanks to the red arrows on the Solution type icons.


This system works well for any type of mate between plane and plane or axis and axis. The only anomaly would be a plane-to-axis mate. This would need to be handled similarly to what the constraint tool does now when we select axes: it would automatically force an Undirected Mate, since that's the only kind that makes sense for a plane-to-axis mate.


As far as converting legacy files to the new constraint architecture, Mate Mates would automatically become Opposing Mates, and Flush Mates would become Aligned Mates. The only automatic changes would be that an axis-to-axis mate would become an Undirected Mate (because otherwise undesired changes might occur), and a plane-to-axis mate would become an Undirected Mate (because that's the only kind it can be). These changes would result in no effect on the assembly solution, so no undesired changes would occur.


I realize this is a slight deviation form the simpler initial request for just an axis flip option. However, it really is the most logical way to implement it. If we're going to add the option to control the direction of an axis-to-axis constraint (or not), then we also need to add the option to control the direction of a face-to-face constraint (or not).


As an advanced action in the event that Autodesk chooses to only implement Axis control per this Idea's original scope, I've created an Idea that covers the need for better control of face-to-face mates as well (i.e., the "free direction" mate).


To help get the momentum going on that enhancement, please consider voting for it as well: Give us better control over face/axis mates.


Thank you!



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