MIRROR PARTS IN ASSY.

[JimSteinmeyer]

I have been working with an assembly today where it is ideal to mirror parts and have figured out how to reuse the parts rather than create new parts. Now I find that when the parts are mirrored, they ate not retaining the mates. Where do I find the setting so they either retain their mates, or prefferably retain the mirror so that if I move the origional, the mirror moves as well?

Thank you

[jletcher]

Yeah thats why I don't use mirror assemblies. I make new. But I thought they fixed this. I don't know because I will never use it after the 1st time with all the bugs.... But I don't think you can make the miror move when you move the base. You can tie peramters form one to the other then they will both move but just mirroring it will not.

[mrattray]

As jletcher said, this is how mirror is per AutoDesk design. Mates between mirrored parts will copy over, mates between mirrored parts and not mirrored will not.

[JimSteinmeyer]

If this is true it makes mirroring about as useless as teats on a boar! I would like to know what the logic behind this move is. I had thought I would try to use another feature and improve my efficency, but if I still have to go back and place all the mates, did I really save any time?

[jletcher]

It did work at one time the only time a constraint would not work is if it was attached to a sketch but like I said it worked once in awhile not all the time. I wrote a vb that did the mirror over and over 100 times constraints failed 96 times..

This is why adutdesk need to stop messing with useless interface changes and get features they have now to work...............

[mrattray]

The only use for mirror is if:

A: I want to make new derived L/R parts

B: I have lots of parts that are mated to each other that I want to mirror over

Note that this is 100% AutoDesk shenanigans, any other CAD software would do exactly what you expected in a mirror operation.

[Cadmanto]

Jim,

Yes, that is one of the things I noticed about Inventor is that when you mirror the parts in an assembly the mates do not come along for the ride.  What I ended up doing is grounding the mirrored parts so I know they aren't going anywhere.

[jletcher]

He wants to animate the mirrored assembly so grounding all parts would not work good for him..

[mrattray]

That's fine if your design never changes. 

[JimSteinmeyer]

One work around could be to make the parts to be mirrored a subassembly so that as the design changes you can delete the mirrored set and recreate them and then ground them at the end. The only reason for the subassembly would be to make them easier to find. However I distintly dislike grounding parts as they can not resopnd to a dynamic design and I usually design as I model.so things have a trndancy to change from the start to the end.

[jletcher]

Do you need it to be mirrored with parts? maybe a dirived part from the assembly? Never tried it but if you dirived the assembly if you animate the base the dirived part would update. also not sure how many parts you have. Diriving the assembly could take a few minutes to do. I did one but not for animating but to send a customer took 1 hour to dirive but it worked..

[SBix26]

In the case in which mirrored parts need to move symmetrically, I would really like to have a symmetry constraint.  The workaround that I have found to be simplest is to create a linkage part which is nothing more than a sketch line.  The attached pneumatic gripper assembly is an example.

In the case of mirrored parts which are not moving, but still need to adjust to design changes as you work, then multibody solids are the way to go, and grounding is exactly how this works best.  The origin of each part is what is grounded, and if the design alters the location of the part relative to its origin, the part moves in the assembly.

[mrattray]

---

@sbixler wrote:
In the case in which mirrored parts need to move symmetrically, I would really like to have a symmetry constraint.

---

I submitted this to AUGI and to the AutoDesk idea submission thingy a little over a month ago.

[JimSteinmeyer]

To clarify what I am doing, I have a trailer that is symetrical from the road side to the curb side. I have several light brackets and load securement brackets that are placed on both sides, symetricly. In making everything fit and line up cleanly I need to move things around to determine the best location. Rather than placing 20 items on each side and mating them all I thought it would be faster to place one side and then mirror them. I do so and then sales informs me that the customor wants the trailer 2 feet longer. No sweat, just change a couple of dimensions on the driving side and..... the driven side isn't driven. Thus begins the search to find how to have the mates mirror with the parts.

I don't think multi body parts are the answer as I still need the assembly to drive a BOM when I am done and if I understand multi body parts, they still boil down to just one part in the BOM.

Sam,

Your idea of grounding, If I understand what you are suggesting, I would ground the part, which actually grounds the coordinate system for that part. Then if I need the part moved I move the body relative to the center point? Interesting idea but with several instances of the same part they all would move which would be bad.

[mrattray]

As far as I know, the only way to do this "right" is to recreate all those mates for the not-so-driven side using parameters to keep things at least somewhat symetric. This illustrates perfectly what I believe to be one of Inventor's weakest points.

[SBix26]

Multibody parts for a situation such as yours (and mine) are the layout.  The various solid bodies are derived into individual parts with their own iProperties, materials, colors appearances, etc., so the BOM is not a problem.  But, each derived part carries the origin from the layout, so when the layout changes, so do all the parts, and if they're all grounded with respect to each other, their location relative to each other matches the layout.  It's pretty powerful.

[JimSteinmeyer]

Sam,

This sounds very interesting and promicing. I will have to dig through the tutorials on multi body parts to see what I can learn. I have always considered MBP as a method to create a single part in context in an assembly and avoided it as not needed. This is apparently not so. Thank you for the information.