Invalid Drive Element

Jim Barkelew

Invalid Drive Element

I'm looking into a problem with a design model and trying to make a simple pass with MAFC.  I get the error "Invalid drive element.  Selected geometry is not supported."

The surface I'm trying to drive is a non-ruled surface with curvature in both directions.  Looking at the cutter, surface curvature, contact height, etc it should drive. I don't recall a problem with any surfaces in the past.  The problem is not unique to this part.

Anybody run across this? And, any solution?  MFG bug? Modeling process error?   

Jim

Steve Beach

RE: Invalid Drive Element
(in response to Jim Barkelew)
I've run into this. i think (Reapeat - THINK) it stems from when a designer got this surface from 'another' part, or meshed it in from another assembly.
We've done (2) different things to get around it.

1) The simple one...... we just went into geometry, and 'offset' this surface with '.0001' offset, then drove that in the CATProcess
2) The harder one is to re-build the local surface by splitting it with several curves, then creating a new 'multi-section' surface, then drive that.

Either way.........you are driving a NEW surface you created.......MAFC doesn't like certain surfaces, and that's just a bug, I believe.

Regards, and good luck Jim

This response will self-destruct in 5 seconds.........

Dave Frank

RE: Invalid Drive Element
(in response to Jim Barkelew)
Hi Jim,

Try Multipocket Multiaxis machining. If you have the License. That is more robust, and can handle drive surfaces made of patches..

Dave

Jim Barkelew

RE: Invalid Drive Element
(in response to Jim Barkelew)
More details as I dig. The surface is a "join" of 9 surfaces. I can drive one of those surfaces no problem. When I try to drive 2 "tangent" surfaces it fails saying they are non contiguous elements.

So the problem I think is the original surfaces are not contiguous so the join is bad.

Still hacking.

RICHARD STEINER

RE: Invalid Drive Element
(in response to Jim Barkelew)

We've done as Steve said - offset the surface by a number.

Another thing we've done is use the Federation tab and play with the options there. I don't remember what options we used but you can also make fewer patches and a cleaner LOOKING part which makes face selections easier. The design experts would know a lot more about that function than we do.

We've also done as Dave said or used Contour-driven machining.

Bryan Carpio Felsher

RE: Invalid Drive Element
(in response to Jim Barkelew)
Another trick is to select the CREATE DATUM icon by double clicking it. This will make anything you create afterwards "dumb"- no history. Then join all the 9 patches into a single dumb surface patch. Sometimes the single "dumb" surface will drive. Yes, I've seen this error a few times, also...usually cominig from small customers making commercial parts designed poorly in another CAD system and sent to me as a STEP model.

Good tips, guys.

Justin Dean Dinneen

RE: Invalid Drive Element
(in response to Jim Barkelew)
I'm logging all those tricks in my brain for sure. thankyou fellas

Jim Barkelew

RE: Invalid Drive Element
(in response to Jim Barkelew)
I copied the offending surfaces into a empty part (as result). I joined the surfaces with federation set to "all" Won't drive. I set the Join to no federation and it drives OK but I have to select the individual surfaces.

Tried to edit the Join in the original design model to set no federation and all the fillets errored on update due to missing edges.

My conclusion so far is for the designer to turn off federation for Join surfaces. The work-a-round sems to be xtract the faces or drive the original surfaces one by one.

RICHARD STEINER

RE: Invalid Drive Element
(in response to Jim Barkelew)

I haven't dealt with this in a long time so I don't know what parts to grab to play with this.

In the Join Definition check the boxes for Check tangency and Simplify the result then try the Federation tab and Point continuity and then Tangency continuity. If that doesn't help I don't know what else to try.

Wouldn't you know it our in-house expert on this retired last Friday.

Samarinder Singh

RE: Invalid Drive Element
(in response to Jim Barkelew)
I have seen this many times and just as Steve and Jim mentioned you have to select face by face.

It happens only when you try to select such surface in one shot either selecting from the tree or sometimes from the geometry view when moving the mouse closer to surfaces' edges (pretty much same way you select the entire sketch from any of its vertices)

However federation of joined surface has its importance in design and in some machining toolpaths as well. And I learned it 4 years ago.

Samarinder Singh

RE: Invalid Drive Element
(in response to Samarinder Singh)

Hi,

Is there any news for this being fixed? I found another one recently where the design came from V4 model for an F35 bulkhead and I thought about using Surface Simplification but I could not find the command in my GSD workbench using PLM express licensing. It was working fine in the regular licensing but I could not check it today because LUM stopped for some reason.

Regards,
Samarinder Singh
Attachments

  • Licensing_2-12-2014 5-38-15 PM.png (69.2k)