The concept behind Mates Z Axes

peter_cuthbert

Good Morning Everybody

As a newbie to OS I have been trying to get up to speed with Mates.  From what I have learned so far they are a brilliant idea and a very useful too.  However, as a former IT trainer I know that there is always the risk that users will build their own conceptual models of how software works which may not match the designer's concept.  The result is usually a poor user experience and many mistakes.

Thus what I want to know is the design concept behind the Mates Z axis.  So for a good (say) Fixed mate to occur do the Z axes of the two mates have to be pointing in the same same direction which logically ought to be the direction in which the two parts come together?  Alternatively, should they be facing each other?

I am also trying to get my head around sketching with Mate Connectors which looks to be a very useful technique but I have not found a good guide on how to use this function.  In my attempts, again the logic behing the Z axis orientation is an issue.  Shoud the Z axis not be pointing in the direction that the line will take?  If so this is problematic for me as I can place a mate but if I am not 'lucky' as to the Z axis orientation there seems to be no way to flip it as you can with the other two axes.

I know that there is good clear logic behind the placement of Mates, but I have not found a clear explanation anywhere.

I would be interested to hear your comments.

Regards

Pete

eric_pesty

peter_cuthbert said:

Good Morning Everybody

As a newbie to OS I have been trying to get up to speed with Mates.  From what I have learned so far they are a brilliant idea and a very useful too.  However, as a former IT trainer I know that there is always the risk that users will build their own conceptual models of how software works which may not match the designer's concept.  The result is usually a poor user experience and many mistakes.

Thus what I want to know is the design concept behind the Mates Z axis.  So for a good (say) Fixed mate to occur do the Z axes of the two mates have to be pointing in the same same direction which logically ought to be the direction in which the two parts come together?  Alternatively, should they be facing each other?

I am also trying to get my head around sketching with Mate Connectors which looks to be a very useful technique but I have not found a good guide on how to use this function.  In my attempts, again the logic behing the Z axis orientation is an issue.  Shoud the Z axis not be pointing in the direction that the line will take?  If so this is problematic for me as I can place a mate but if I am not 'lucky' as to the Z axis orientation there seems to be no way to flip it as you can with the other two axes.

I know that there is good clear logic behind the placement of Mates, but I have not found a clear explanation anywhere.

I would be interested to hear your comments.

Regards

Pete

There are some subtle nuances with mate connectors and mates for sure but I think you might be over-thinking it a bit...

It's important to differentiate between mate connector themselves (both implicit and explicit) and assembly mates.

Mate connectors are basically just a coordinate system, when used as a sketch plane, the x and y of the mate connector are the x and y axis of the sketch so Z is the 3rd "out of plane" direction.

Whether you use an implicit mate connector (that you pick on the fly) or an explicit one, you do have full control of the orientation (and position) through the dialogue, you can not only flip but also "reorient" the primary (Z) and secondary (X) axes based on any other geometry and/or apply offset and a rotation.

Assembly mates define a spatial relationship between two mate connectors, however whether the Z axis is aligned or opposite doesn't really matter and it will just snap to the "closest" when you start a mate, note the options for flipping the z axis and rotating in 90deg increment in the mate dialogue affects the relationship between these two mate connectors. 

Here are a few videos discussing some of the finer points, part1 here: https://www.youtube.com/watch?v=HUVFq7tixKM

Ste_Wilson

I would suggest the assemblies course in the selfpaced courses section of onshape learning center.

Mate custom mate connectors can be moved and rotated. A click on the custom mate displayed in the dialog box will show the options.

What's so special about z?

eric_pesty

peter_cuthbert said:

Good Morning Everybody

As a newbie to OS I have been trying to get up to speed with Mates.  From what I have learned so far they are a brilliant idea and a very useful too.  However, as a former IT trainer I know that there is always the risk that users will build their own conceptual models of how software works which may not match the designer's concept.  The result is usually a poor user experience and many mistakes.

Thus what I want to know is the design concept behind the Mates Z axis.  So for a good (say) Fixed mate to occur do the Z axes of the two mates have to be pointing in the same same direction which logically ought to be the direction in which the two parts come together?  Alternatively, should they be facing each other?

I am also trying to get my head around sketching with Mate Connectors which looks to be a very useful technique but I have not found a good guide on how to use this function.  In my attempts, again the logic behing the Z axis orientation is an issue.  Shoud the Z axis not be pointing in the direction that the line will take?  If so this is problematic for me as I can place a mate but if I am not 'lucky' as to the Z axis orientation there seems to be no way to flip it as you can with the other two axes.

I know that there is good clear logic behind the placement of Mates, but I have not found a clear explanation anywhere.

I would be interested to hear your comments.

Regards

Pete

There are some subtle nuances with mate connectors and mates for sure but I think you might be over-thinking it a bit...

It's important to differentiate between mate connector themselves (both implicit and explicit) and assembly mates.

Mate connectors are basically just a coordinate system, when used as a sketch plane, the x and y of the mate connector are the x and y axis of the sketch so Z is the 3rd "out of plane" direction.

Whether you use an implicit mate connector (that you pick on the fly) or an explicit one, you do have full control of the orientation (and position) through the dialogue, you can not only flip but also "reorient" the primary (Z) and secondary (X) axes based on any other geometry and/or apply offset and a rotation.

Assembly mates define a spatial relationship between two mate connectors, however whether the Z axis is aligned or opposite doesn't really matter and it will just snap to the "closest" when you start a mate, note the options for flipping the z axis and rotating in 90deg increment in the mate dialogue affects the relationship between these two mate connectors. 

Here are a few videos discussing some of the finer points, part1 here: https://www.youtube.com/watch?v=HUVFq7tixKM

peter_cuthbert

Hi Eric and Fellow OnShapers

Many thanks for your comments and especially for the link to the YouTube videos.  I think that the author is coming at the issue in much the way that I would have hoped and having seen what he had to say I feel much more comfortable with using Mates.  I have re-assembled a 'tricky for me' product and was astonished that every piece acted as I expected with my new skills.  Very nice experience.

Do you have any suggestions for sources to help learning how to use Mates in sketching?  I have created a drawing of a heating coil by copying a size adjusted JPG, but had some difficulty where the pipes changed planes.  I have discovered the Bridging Curve but was also advised by another contributor to try using mates in sketching to get over the different planes issue.  He sent me a nice example model, but I do not seem to have understood the steps he took in making it despite my attempts to edit it.

My model is here:

https://cad.onshape.com/documents/f1491b2b2fd033117262c961/w/d18d7271fc87be9de2e73d4c/e/46214cb473548898b42de6d0

Best wishes

Pete

eric_pesty

I think the key thing about using mate connectors for sketching is that they are are useful shortcut instead of using planes, basically it lets you define an origin and orientation for a sketch "on the fly" by using the mate connector controls.

There is some discussion here: 
https://www.onshape.com/en/resource-center/tech-tips/tech-tip-sketching-with-onshape-mate-connectors

The typical scenario is to just use the end of a segment on one sketch to create a sketch perpendicular to that for the next segment.