Multi body part modelling-Transitioning fron SolidWorks to Creo

As a follow up to this, and reading further posts on this matter, it appears many Creo users have issues with this as they fear it might affect how Creo handles bodies in Windchill. Can I suggest, that from a part modelling perspective, this is an irrelevance. I cannot emphasise how critical this is to our (and others like us) workflows. I can think of many modelling tasks that are simple in SolidWorks or Fusion, using multi bodies, that would require ridiculous workarounds to achieve using feature only modelling.

If PTC is hoping to persuade others like myself to switch from SolidWorks and the like, this has to be addressed as a matter of urgency.

As I said in the other post, don't hold your breath that PTC will change their core design philosophy after 20+ years and allow multi-body part files.

Did you research NX as a comparison to Creo? NX has easier to use surface modeling tools and allows multi-body parts.

Creo is not the High-End product advertised.  They are an ancient, decrepit excuse for CAD.  This is only one of hundreds, maybe thousands of good examples of how the software hasn't evolved and why their market share is embarrassing.  If it weren't for legacy customers in defense and government, would PTC even exist?  I mean, really, we remember when Pro came on the scene and there was no stopping them.  But it looks like they stopped themselves.  Archaic interface, poor integration with Windows, horrifying usability, and so on.

Multi-body functionality is an advanced feature that, once learned, enables the user to much more powerful modeling workflow in many instances.  I figured this out in the early 2000's when I had just started using SolidWorks.  Our division at Northrop was using SolidWorks and we were very close to some of the top brass there.  They would come see what we were up to quite often and used our massive assemblies to improve the product.  At that time, assemblies in the 40k component range.

I had come from solid modeling in AutoCAD where Boolean was a very useful tool.  I quickly found out that SolidWorks at the time did not have this capability so I requested it.  Shortly thereafter SolidWorks created the multi-body capability.  Now it is one of my favorite features.  Using it doesn't necessarily come instinctively, but once you "get it" you can't go back.  It's an awful thought that I will not be able to use it in Creo despite Creo being billed as "high-end" and SolidWorks only a midrange product.  So far, from what I've seen, except for ZTG and direct editing, I would put SolidWorks up against Creo any day of the week.

One example of the power of multi-body functionality is a weldment my team was working on years ago, around 2013.  The weldment had roughly 1000 parts consisting of 250 drawings (sub-weldments and unique parts).  No one would ever update the weldment whenever a new machine was designed because of the complexity of the drawing package and all the work to change it.

Using SolidWorks weldments feature, which leverages the multi-body functionality, we reduced the drawing package to about 35 drawings!  If you consider that in a 1000 part assembly you need at least 3000 mates (or what Creo calls "placements") to fully constrain the assembly and then in the new assembly you would need about 35 x 3 = 105 mates, which one would you rather manage??

One weldment I designed had about 200 members in it and about 90 were unique.  I did this in a single part.  One part...One part number...One description...One drawing with 90 details.  This versus 90 parts, 90 part numbers, 90 descriptions, 90 drawings. I find the thought of doing it the "old" way hilarious.

Because of the way SolidWorks Weldments works, the relations between all the welded parts stays within the part and eliminates the need for mates.  This:

1. Makes it extremely fast to model complex, welded parts.  For instance, I had a team of myself, one engineer and one to two designers and we could model complex oil drilling equipment with tens of thousands of parts in a matter of months.  I don't see this ever happening in Creo.

2. Makes the model more accurate as the relationships between bodies stay in the part and not at a higher level in the assembly where things can quickly go wrong.  This gives more accurate geometry that has less gaps or interferences.  This is extra-helpful when moving the model into an FEA program.

3. Makes it extremely fast to modify the model.  The frame weldment mentioned above with 200 parts may have taken days to make major changes, but in reality only took hours when I did have to modify it.

4. Makes documentation infinitely faster.  I don't want to make a drawing for every piece of cut structural steel when a cut list is sufficient.  More complex welded members can have a drawing detail, but why make a new part number and new drawing for each part in a weldment?  Some say that each part needs a unique number for manufacturing.  That is easily resolved with a dash number for each cutlist item.

5. GREATLY improves performance.  Now a fraction of the mates (placements) need to be evaluated compared to the old way of doing it, and SolidWorks has the ability at the part level to "LOCK" the drawing tree.  This in effect forces the part to only rebuild when loaded and then never again in session!!  The performance gains due to this are phenomenal.  If SolidWorks users understood properly how to utilize the software, then this wives-tale about Creo being better on large assembly performance would be in the CAD museum where it belongs. 

Right now I came across this thread because I have imported a simple assembly from a vendor into a part (has to be a part) to save as a COTS item.  The problem is that the vendor had threads in their assembly and our policy is to remove these threads, which are interfering in the model between the hardware and the model's main body.  I never had to remove threads in SolidWorks, but I guess for Creo you need to.  So, in SolidWorks to do this you simply make the cut and tell it which solids the cut effects.  I can pick the screw.  I can pick the body.  I can pick both.  Whatever.  SUPER FRICKEN SIMPLE.  I can not figure out how to get this to work in Creo.  Granted I'm new to it and have found that often you can get something done in a roundabout way, but really?  Do I really have to start this over as an assembly, modify it, save it, and then re-import it in as a part?   Wow, really efficient!

All of the ex-SolidWorks users I'm running into that are having to use Creo due to program requirements ARE NOT HAPPY.  This should tell you clueless exec's something.  I'm guessing your programmers have already mentioned much of this to you but the decision makers probably can't even open the program and draw a line (although I bet they could figure it out in SolidWorks).  Kudos on buying Onshape, though.  Please tell us some of this innovation will make it into future versions of Creo!  And do please explain to us why multi-body functionality shouldn't be part of your program!

Multibody will be introduced in Creo 7.0 (April 2020).

Regards,

Domen