New User: Weldments, mirrored structural members not associative

[dennis.parr]

I'm new to Inventor. I going through the weldment or "frame" design process. I created the body to define my LxWxH of my frame. I added a sketch for a gusset. In the assembly I added my structural members to get my frame base. Then a structural member for one gusset on the bottom back left corner of the frame. I mirrored the gusset to the bottom front left, then both of these to the right bottom corners. Then all of these to the top of the frame. Then I change the angle line in the sketch controlling the length of the gusset from 12" to 10" and low and behold, NONE of the mirrored gussets updated. Do I really have to pull a structural member for every gusset? Solid Edge, Creo, Solidworks, everyone else treats these mirrored features as associative to the parent. Am I missing a setting that isn't turned on or something. This will get really annoying really fast if I can have a structural member that will be the same in all locations be linked to the parent.

[MikeKovacik4928]

Dennis

The bad news is, that it is one of the things that inventor cannot do.

See attached link

https://forums.autodesk.com/t5/inventor-ideas/treat-quot-mirror-quot-in-an-assembly-like-a-pattern-m...

It had been put forward as an idea here and also other posts numerous times since 2015.

It is definitely not in 2018, I don't know whether 2020 has it. (I don't think so - someone with 2020 can confirm)

It either has not enough votes, or is too difficult to incorporate into the existing program,

Autodesk themselves, will have to answer that one for you.

Inventor is a wonderful package, but that capability would make it so much better!!

Michael Kovacik
2d & 3d Autocad and Inventor designer/draughtsman/trainer
Inventor Pro 2018; Autocad 2018
.
Draughting/Designing (Manufacturing) (32 yrs)
-Drawing Board (3 yrs)
--Cad (29 yrs)
---Cadkey (4 yrs)
---AutoCAD 2d & 3d (16 yrs)
---Inventor (5 yrs)
---Autocad and Inventor Simultaneously (5 years)
.
Johannesburg, South Africa
.
(Impossible only means you haven't
found the solution yet)

[jtylerbc]

Especially since you're new to Inventor, let's clarify some things about terminology and what you've done in your model up to this point.

In Inventor, "Weldment" and "Frame Generator" are two different tools, which can be used together, but don't necessarily have to be.  It sounds like what you're actually talking about is actually Frame Generator.  Is that correct?

What @MikeKovacik4928 said is technically correct, but I'm not sure if it applies to what you were actually doing - partially because I'm a little unclear on your exact workflow.  Can you share some pictures of your frame and gussets, as well as an explanation of exactly how you got to this point?  It would be easy to give you irrelevant (or even completely wrong) advice just because of misunderstanding what you're trying to do.

It sounds like what you did is use Frame Generator to place your first gusset, then used Mirror Components to make additional instances in other locations.  Is that correct?

[johnsonshiue]

Hi Dennis,

Michael may be right but it is better to see an example. Please share the files here so forum experts can take a look.

Many thanks!

[dennis.parr]

Mike, yes I'm talking about the Frame Generator. I did use the frame generator to place the first gusset, then mirrored them as needed.

I did find an option after creating the frame using the generator, and mirroring my gussets I found a command I believe was "make weldment". Once I did this then the options to add welds became available. Then when I changes things like the root spacing, the mirrored gussets updated. So it looks like the linking does occur, but not until you tell Inventor to make your "frame" a weldment. I attached a screen shot of my frame. You'll see the gusset tubes in the corners.

Thanks for your help.

[dennis.parr]

See zip file "MyFrame-2019-06-25.zip". Thanks for everyone's responses. I think I've got it whipped. When in doubt, right click.

[MikeKovacik4928]

Denis

I was talking about plain inventor files (ipt, iam) not frame generator.

I am unfamiliar with frame generator, my apologies

Mike

[jtylerbc]

---

@dennis.parr wrote:

I did find an option after creating the frame using the generator, and mirroring my gussets I found a command I believe was "make weldment". Once I did this then the options to add welds became available. Then when I changes things like the root spacing, the mirrored gussets updated.

---

What you think fixed the problem is actually just a coincidence.  Formatting the frame as a weldment has no effect on what the Mirror tool does.  Your problem here seems based on some misunderstanding about two things:

1. How Frame Generator models (especially their file management) work.
2. How the Mirror command in Inventor works.

My guess is that the real difference is that you mirrored things differently the first time than you did in this file set.  I can't see your original version, so I can't really confirm that, but I strongly suspect it.  However, that is secondary to a much bigger issue, and solving that issue will make the mirroring problem a moot point, because you won't need it anymore for a model like this.

Your file structure, because of misuse / overuse of the Mirror tool, is a bit of a mess.  You have subassembly after subassembly that are mirrored copies of each other, when you never really needed to do that in the first place.  There are far better tools available than what you used.  For comparison, the fileset for a frame like that should have only contained about 20 files or so (rough approximation, I didn't count item by item).  Yours contains over 130 files.  Some of those are likely leftovers from size changes, but even excluding those the number of files involved has been severely exaggerated by the techniques you used. 

I do some work very similar to your frame, and use FG often, so I think I can help you out with this.  I'm a little swamped at the moment trying to finish up a drawing set, but I'll try to come back later this afternoon with some more detailed explanations and an example of how I would have modeled something like your frame.

[jtylerbc · Accepted solution]

@dennis.parr,

See attached demo frame file set to go along with the following explanation.  I'll try to follow up later with a more in-depth explanation of the Mirror tool in Inventor, but since my explanation here will basically tell you not to use it with the frame, it seemed like lower priority than helping with the frame itself.

The way you were using it, the Mirror tool is intended for creating mirror-image copies of a part or assembly.  Think of something like a pair of brackets with left and right-handed versions.  Using the command this way results in associatively-linked copies of files, rather than just additional instances in your assembly.  This is the reason for all your "_MIR", "_MIR_MIR", "_MIR2_MIR", etc. files.  While it is possible to use the Mirror tool without making a bunch of excess files like this, it is still not the ideal tool to use in the context of a Frame Generator model.

Instead, you should be looking at drawing the entire skeleton of the frame, as I did in the attached example.  Then use the frame "Reuse" tool for the duplicate members.  The process I would recommend would be as follows:

1. Place only one of each unique member.
2. Do as much of the end treatment (Miter, Trim, etc.) as possible with those pieces.  This will help you tell if the Reused instances are oriented correctly or not.
3. Use the Reuse tool to place duplicate instances in the desired locations.
4. If the orientation of the copies is not correct, use the "Change Reuse" command to flip or rotate them as necessary.

In your model with all of the Mirror operations, you have more files with some sort of "_MIR" designator than there are files in the entire set for my demo.  It is a much cleaner file structure, even if your method was giving you the correct geometric results.

A few things to note:

• My frame model is similar in concept to yours, but I didn't bother measuring yours to make it exactly match.  I just made up dimensions for something similar-looking.
• For now, I did not bother including the mounting plates on the bottom in my demo.
• You used a solid to define part of your frame geometry.  I typically don't do this, and didn't in this demo.  However, there is nothing particularly wrong with doing so.  The way I drew it is not necessarily the one correct way to do so.  It is just one of the possible correct ways.
• The top and bottom panels of our frames are identical.  I initially drew the bottom.  Rather than duplicate that effort on the top section, I just projected the geometry from the first sketch to the second.
• I used a single 3D Sketch to place the lines for all four corner tubes.  This would have required two 2D sketches to connect the frame.  Where possible, I tend to do this with a 3D Sketch so I can get them all at once.  The corresponding edges of your solid could serve the same purpose.

[jtylerbc]

@dennis.parr, rather than rewriting almost the same thing, here is an old thread where I was discussing the Mirror command's nuances and limitations.

https://forums.autodesk.com/t5/inventor-forum/mirrored-components-in-boms/m-p/2783152

Nothing really significant has changed about the way mirrored components work since then, so even though it is almost 9 years old, it still applies to your situation.