Best Of

After seeing all of the strange cases that had to be considered with Assembly Mirror I can understand why it took as long as it did to happen. It's a lot to wrap my head around. Glad it's finally here though and the implementation is as thoughtful as ever!

Yes, this has made my day—mirror in assembly. Looks great, and I can not wait to use it. This should hopefully save days, if not weeks, of work per year.

Mate Connectors are Planes
Mate Connectors are Points
Mate Connectors are Coordinate Systems
Mate Connectors are Directions

Correct we are not flipping thread tags in the hole feature but if you model threads it will.

@mlaflecheCAD
It's convenient that implicit MCs work, but I agree with @david_littlefair373 's basic point. We need a default way to reference the origin and/or the non-existent default datums of an assembly.

See:
https://forum.onshape.com/discussion/24162/assembly-planes-where-are-they
https://forum.onshape.com/discussion/16948/cross-section-through-origin-by-default

True,

Having the option to include MCs at the origin by default would basically solve this.

The section view is actually more of an issue. I'm not sure why the section tool doesn't allow implicit mate connectors! Especially since you can snap the section point to any implicit MC locations after it's been created! If you don't have a starting point you first have to add an explicit MC (at least you can use the right click and add to instance shortcut), which is pretty dumb… If mousing over the origin gave you the option to pick one of the directions to start the section I would think it would mostly solve the issue…

Haven't had a chance to watch yet, but @GregBrown has a detailed look at Mirror in Assembly:

RE default planes:

The only issue I can think off is if you have "stuff" that make selecting the origin tricky but hardly a difficult process…

Adding the option to save an assembly "template" would allow users to add 3 default MCs on the origin and solve this (and other requests…)

David - thank you for your comment and all discourse is welcome.

Yes this comment is below Michael's, mia culpa and while there may be legitimate reasons to use an implicit MC, I agree that while 'mating as high in the tree as possible' (as a parametric modeling standard) can involve planes, there are many benefits to Onshape that obviate this. One is the use of high level mates enabling most parts to be mated using only 1 mate - this is made possible by MC's (planes encourage use of low level mates - which are still provided in Onshape because we love everyone :)). I will point out that you are more than welcome to add a MC to the origin as I agree it makes sense if this is the mid plane of the assembly that you would like to mirror. I will leave you with an ask - moving forward we intend to leverage MCs in more and increasingly powerful ways. If there is something you feel we could do to improve MC's, please let us know. Meanwhile please enjoy mirror and remember, this is our first release and we want to know where you think we should take it.