Model based definition: Free-For-All mode

[tlebrun]

Hi,

My company wants to explore model-based-definition for our future.  However, it appears it's still missing a ton of annotations found in current drawings.  Also, we break a lot of rules, and the current MBD seems to be locked down to a standard(s).

^^^^^

Here is an example of what we'd need to do.

* Composite Datums (A-B) 

* adding feature-control-frames to leader notes and dimensions. (as shown below) [because we dimension to the center of the groove]

* Dual units !!!!!

* Assemblies !!!!  No MBD for assemblies currently.  Often we weld 2 rough parts together, and post-machine them.  For us, adding pins, or helicoils to a part makes the part an assembly.

* Welding symbols

* Centerlines.  Lots of dimensions are snapped to centerlines (mostly bolt circles)

Currently we are using Inventor 2023, and I'm not sure how much MBD has evolved.

Anyone know if/when we would be able to use MBD with the features within this post?

Thanks for reading.

-Tom

[johnsonshiue]

Hi! In terms of MBD workflows, there aren't further enhancements in 2024 and 2025, compared to 2023. Let me clarify a few points.

1) The dual unit is supported. Modifying the current 3DA style is a bit painful. You will need make Styles Library editable and open a drawing -> Styles Editor -> Dimension -> find the desirable 3DA Dim Style. Turn on the dual unit option (very similar to 2D drawing). Save the change and save the styles back to the Styles Library. Open the iam and ipt files (including templates) -> Manage -> Styles and Standards -> Save.

2) Indeed, the MBD workflow is still strictly at part level. 3DA is available at the assembly level.

3) Welding symbols are only available in the Weldment environment in a Weldment assembly.

4) Indeed, there isn't a centerline command in 3DA/MBD but you can create a centerline in a 2D Sketch or 3D Sketch. Or simply create a workaxis. Then you can dimension to the geometry.

Many thanks!

[James_Willo]

Hi Tom, please also note that MBD is designed to be strict to standards. In fact, the tolerance analyser actually goes through an algorithm to recognise the geometry and only suggest tolerances that are possible for that type of geometry and the selected standard. 

[NigelHay]

In the drawing environment, you do not have to create a centreline in a groove (unless you specifically want to see one). You can just dimension to the mid point of the groove. The dimension command will snap to the mid point, assuming that the groove features are symmetrical.

The welding symbol is also available in the drawing (the one I've shown is nonsense, just for illustration).

[tlebrun]

Thanks for the replies, John and James!

[tlebrun]

James,

Here's a page from ASME Y14.5-2018 that shows having 2 datums, total-runout to themselves.  Something we do also, but can't in MBD (at the moment!)

[Frederick_Law]

Who will be using your MBD model?

Are they using Inventor?  Or you'll send them STEP?

If they're using STEP then you should test and see if they get everything from STEP file.

Not all software implemented MBD the same.

Not all are up to date.

You might end up doing MBD and 2D drawing.

[tlebrun]

We intend to create STEP (242) files, and 3D PDFs, and slowly fade away from making 2D drawings.

[Frederick_Law]

Test your "tool chain" and make sure all the information is getting across.

Don't just create STEP and PDF believing whoever receive it will get everything.