iPart (&iAssembly) vs. Skeletal workflow.

[dgeise]

Hi all,

I've been away from Inventor (and CAD in genreal) for a long time.  I let my old license upgrade-lapse, but I'm contemplating giving her another try, first with a 30-day timebombed trial license, then perhaps the 'lite' version if things work out.

But before I start down this road, I was hoping folks could share whether the improvements I neededed (and the reasons I moved on to other products & projects) have been addressed.

Basically, I want to create a top-down skeleton-driven assembly, then use Inventor's iPart/iAssembly functionality to add a level of structure & formality.

I asked about this a long time ago here http://forums.autodesk.com/t5/inventor-general-discussion/custom-ipart-in-a-skeletal-assembly/m-p/19... and unfortunately the answer was a bit lacking.  I ended up abandoning the project for multiple reasons, CAD issues being a primary one.

Digging around the Internet, it doesn't seem that anything has changed.  Am I missing something?  Has the whole skeletal-modeling approach been depreciated in lieu of something better?  If so, can someone please give me a general outline & some giudelines on how to accomplish my general goal?

To be specific, myy high-level goals are to end up with a robust parameterically-driven assembly (basically custom sheetmetal parts with standard fasteners) where everything always bolts together properly, dimensions can be variable (forget the iTerminology here) but only within defined linits, and multiple parts & part features & materials can be selectable at assembly creation time.

Is this possible?  This seems what iAssemblies are for, so perhaps I am just misunderstanding things?

Since I'll only have 30 days to figure out if Inventor will be able to do what I need, I'm hoping someone will be kind enough to illuminate things before I do the install and the count-down timer begins ticking.

Thanks in advance, I'm looking forward to getting back into the swing of things here!

Thanks in advance,

--Dave

[EDIT]

No, this wasn't very clear...

I used to define only general parameters & part-part interfaces (think bolt holes) in Skeletal model using only planes, sketches, & work features, then derive that into multiple parts, add detail & make solid, then assemble the parts into the assembly.  This won't work since I need to drive parameters into an abstract (skeleton) part.

Skimming the forums here a bit, it appears that nowadays the approach is to create (multi body) solids in the skeleton, derive that into parts, then assemble.

This sounds reasonable - will this approach be compatible with making an iAssembly?  I'm guessing that the skeleton part becomes an iPart, and the part is marked somehow as 'abstract' in the ultimate assembly, but I'm not sure I understand how the derived parts will be generated by the iFactory.

Are there any tutorials someone can point me to?  I'm finding lots of interesting stuff but nothing that seems to be along the approach I just outlined.

[RodrigoEiras]

Hi dgeise,

In my experience I would say the equivalent of the skeleton approach in Inventor would be the use of Multubody Parts.

The basic idea is you create all the no library parts as separate solids in the same part. All the parameters are stored in this multibody part.

Once this is done you can use the function Make Components to turn the solids into independent part files.

Then you must create an assembly inserting the multibody part as a Phantom part (and manually turn it's weight to zero), so all parameters will be available in the assembly through this part.

Then you can insert all the parts as rooted and grounded, then you don't have to care about constraints.

Library parts can be added then, and then you will need to use constraints.

In a quick answer I think this is what you were asking for.

Best regards

[dgeise]

Thanks Rodrigo, that's a big help!

I sort of surmised what you're saying while scanning the forum here over the weekend.

While I have your attention, I'm wondering - I read a question that mentioned that sheetmetal parts (aka the sheetmetal program) isn't conmpatible with multi-body.  I dropped Inventor in 2007, right before they added multi-body support if I recall.

I'd like to create the skeleton using the sheet metal program.  Will it's issues with multi-body cause me problems?  I konw I can fake the sheetmetal program, at least for simple stuff, but some of the anticipated bends will probably get a bit complex at the ends of the bend lines...  Will this be a major problem for me?

Thanks again, I really appreciate the help.

--Dave

[RodrigoEiras]

Hi Dave,

Unfortunately I am not using Sheet Metal parts, so I am not sure this would work for you. Anyway it seems that multybody parts for sheet metal are somehow supported in the last versions. Maybe that can help you.

https://www.youtube.com/watch?v=cIaVkeoam90

Best regards