CAD Assembly

[kingsld1]

I've imported a part model into a fixture model. I need to transform the part model so that it fits correctly on the fixture model.

Problem is that the assembly tree only has one branch. By that I mean all the components that make up the part or fixture are at the same level. I can't just select the overall part or fixture model and transform it all in one go.

The ever helpful help file leads me to believe that I can create an assembly (or part) from components that I select. However, it is extremely vague on the specifics on how to do that. I have not been able to figure it out.

Anyone have any experience creating an assembly/ part in PC DMIS? I'm sure it's easy once you know how....

[WM321]

I do it simply by importing the separate part and fixture models. When prompted when importing, select merge. If your separate models are not sitting in relation to each other as they would in the real world, use the CAD assembly button. In it you should have a list that is expandable (not sure why you don't). You can then right click each item and select transform, to move them separately as required.

If you have assembled the various models in something like solidworks and import the assembly as step, you will only get one model, which can't be separated easily. If you import the assembly in iges you should get an expandable list that can be transformed and switched on/off separately.

If you want to transform the whole of the imported models or assembly, simply right click the unexpanded item in the CAD assembly list and transform.

How are you importing, and in what format?

[kingsld1]

I'm importing step files. Step files were created using R&R's Fixture Builder software. Created my fixture and then I imported my part model into fixture builder. There is no unexpanded item to transform. Trying to create that unexpanded item is the issue.

I transform individual components on a semi-regular basis. This particular part has more components than "normal" and was hoping to find a better way.

[WM321]

So fixture builder gives you the fixture as a step file as you need it? But you can't transform the part in fixture builder to sit on your fixture as required?

If so then import the CAD for the part, then import the step from fixture builder without the part, merge, and use the CAD assembly as described above to transform your parts separately as needed.

[kingsld1]

Fixture Builder is being awkward with this part/ fixture setup..... Either that or I need better training. Difficult to see when the part has made contact with the fixture. In PC DMIS I can make components visible or invisible as needed so that I can accurately position components. In any case, I still would like to be able to group things together in PC DMIS and be able to transform them as a group as needed.

[Schlag]

100x easier to do "outside" of DMIS in actual CAD software. If you have access I recommend it or ask an engineer to make an assembly and import the "whole package" as 1 iges with the orientation already correct to how it will be inspected. Not that DMIS cant do it but there are always multiple options.....

[mrollings53]

Bad idea if your customer cares any amount about model integrity. Who knows what voodoo math is happening to the part model when you add it to a bunch of other stuff, then create a new file with a completely different structure from what was originally supplied.

I'm not innocent of this either. We run CMM Manager on another machine. Because it was poorly setup, and no one knows how to use furniture properly; we have to create assemblies in Solidworks to add any sort of fixture, and convert STEP files to IGES for import.

[Schlag]

We use solidworks. Creating an assembly with the part model and fixture standoffs / clamps, or sometimes a custom fixture. When you iges that "assembly" all the components are recognized and individual components, they just move as a group. I have never had anything "loose" intergrety. But, its all about tegrity.

[mrollings53]

Don't import your part file into fixture builder.

All of the models are separate entities. Import the fixture model into PC-DMIS, then import the part model; keep importing models until you have the entire setup. Then move things around to how you will lay them on the rock.

Because your part model and fixture model are on one file PC-DMIS will transform them together as if they were one part.

[kingsld1]

Agree that in theory it's easier to have someone else do it. Don't have access to CAD software nor do I have any training in it. I've asked for both pretty much every year during reviews but no joy. I have a drafting degree but got it a year or two before any CAD course was available at the junior college. Moved into quality within 18 months of getting my degree, never needed CAD training and never went back to school.

It would be difficult to get our CAD guys to make a complete part/ cad assembly. They're pretty busy. Don't want them creating fixtures from scratch because they can be clueless about what is needed at times.