How to define an Angle Mate?

david_58

Is there any way to define an Angle mate?

David

jakeramsley

Hi David,

I assume you mean an angle mate such as keeping two faces or edges at a defined angle?  If so, I would use a fasten mate at the axis of rotation and then rotate the first mate connector by the desired angle.

1. Insert the two components you want an angle defined between.  I have the same part twice, the first one is fixed at the origin.  Start a fasten mate and select the point on the first part you want to rotate about (I inferred to the face so that I could rotate about the z-axis)


2. Select the point on the second part that creates the correct center of rotation.  Since there is no angle defined, these mate connectors will be aligned and currently be fixed.


3. Now that the fasten is created, we need to edit the mate connector definition to have an angle involved.  Expand the fasten mate to see the two implicit mate connectors.  Right click on the top one and choose edit.


4. With the edit mate connector dialog open, select the "move" checkbox and see that there is a "Rotate about z-axis" option.  Enter the desired angle and hit enter.  This now fastens the two mate connectors with an angle of the angle entered.


For completeness, I would rename my mate to reflect that it is an angle mate.


If you were hoping to make a different kind of angular mate, let us know and we'll see if we can help.

david_58

Thank you. It works for that case, but I can't figure out how to make it work in this case:

jakeramsley

In order to specify the angle, you need to use a mate that constrict the angular degree of freedom.  Using a revolute like you are showing allows for the two mate connectors to rotate relative to one another about the blue/z-axis of the mate connectors.  Rotating the default position of the mate connectors like I did in my steps won't have any effect in this case because that degree of freedom is still unconstrained.

If you are trying to do something that limits the range of revolution, we don't have that implemented yet.  If you want something to be a fixed angle relative to another edge/face then try the method I have listed above.  If you are still having issues, you can share your document with support and we can try to collaboratively work through the issue.

traveler_hauptman

@David The mates don't allow parameters; so the workaround is to manipulate the parameters of the mate connector (I wish they would use a less confusing name for these).

My recommendation, if you want to be able to move the hinge by hand part of the time (to get a feel for the motion, check for collision, etc) then you will need the revolute mate that you have; then to lock it at an angle (to check for design issues in a specific phase of the motion, or to just not have to worry about stray drags messing up your model while working with it) you will need a second fasten mate that you enable and disable.

eric_wood959

Looks like this can also be achieved now by using a revolute mate with limits.

Ralph_Hamilton

The problem is, how do you set a reference point (edge or face).  On this Machined Bracket exercise, how would you set the second bracket at a 45 Degree angle from the first bracket?  If the user could set the Triad to a zero angle, I think that might work. 

matthew_stacy

@david_58 / @jakeramsley / @traveler / @eric_wood959 / @Ralph_Hamilton,

You can set the initial hinge rotation with a revolute mate.  The trick is to edit one of the mate connectors in that revolute mate in the assembly (right click on the mate connector > edit > rotate about Z) THEN right click on Revolute 1 and <Reset>.  That RESET is critical.  That manual step is what sends the mate to the initial Z rotation that you specified.

https://cad.onshape.com/documents/80dabc1114bbc6e47e9974f3/w/f3f7d2a4a1877022ff9f6873/e/f938bdb56377af9848f16a8d