working with imported (messy) iges/step

[Anonymous]

Other than a few things like, bending parts (I'm aware of the sheet metal trick), faster ways to draw 3d curves, and a general lack of tools in the patch modeling mode, one of the big hurdles for me is a workflow with getting quite a bit of data workable for what you'll need to work on.

Right now, our workflow for most of the designers, is to digest the data in Rhino, layer it out quickly, and work from there. Moving the data around to something useable is the big hurdle in Fusion. I actually import the data often in Fusion just because it's a slightly better translator. But So many times the data has been a grab-bag of data from various Chinese manufacturers using one software, that then is translated into Creo by someone else, who added some, then some was imported from Solid works. You just have no idea, or control. Who knows where the data came from. Much of it's just for space claim anyway. BUT what happens is I get a few hundred parts, then about 5000 unstitched bodies. 

I'd like to say I'm exaggerating. 

So how the Heck am I fixing that in Rhino? Well, various tricks. Much of the data is garbage we throw out anyway. So first, I select small parts. Give that a visual scan. Anything smaller than 5mm on something the size of a desk usually gets tossed. 

Next I select anything smaller than a certain area. If a stitched or unstitched surface is smaller than 1 square mm, you can likely just delete that. There are usually a few "surfaces" that just end up with no actual size. I mean, they Technically exist, but only with some scientific notation. So you don't need those. 

Ok, now we're a few thousand unstitched surfaces down and can start sorting things a bit.

When I'm lucky, a few parts are colored uniquely. Select color, and stitch (join in rhino). Any time I'm finished with something like that I throw in on a well named layer and hide it. 

Now, I'll hide all the unstitched stuff and sort through the joined items. I just throw those on some named layers, usually by material type. Thermoformed white plastic goes here, white sheet metal here, black sheet metal there, rubber parts here, etc.

Now I just show the bodies. If I'm lucky I can just select all and hit join and go grab a coffee. That'll just stitch anything that's connected. The Downside to that is if a part touches the pair next to it without a gap, you likely join them together into one part (potentially creating some nasty geometry). But it's not the end of the world. Those parts, you'll have to just split up and stitch more carefully. There are usually only a few.

I think you all get the idea at that point. Near there end there are usually 3-4 trouble parts. But in the end I end up with usually about 5-10 main layers, with 5-10 grouped layers under those to organize everything. Now, I know that's now how organization works in Fusion because Fusion works on parts and components only. That's the engineering side that makes organization suck. Oh, you have 1280 screws? Well good luck with That! Every time you expand that component list you're screen will go black and nearly crash, which is what happens when I expand the non-stitched group of my imported file. 

I've been looking to see what other people are doing. The vice video is the only example I can find of dealing with neutral (iges/step) data. But they used a very ideal situation, and a file with only several parts rather than hundreds of parts. I get that, for the sake of the quick tip, but really what I'm looking for is how to clean up files into something useable. I haven't found a workflow that's worth it yet, and that's what I'm looking for. 

If anyone has any guidance in how to handle data like that, or simply shares my frustration in having to simply use different software for speed, chime in. If I could come up with an efficient workflow then we'd probably get a few seats after I train people on it. But for now, you open the file and it just seems like you can't realistically do anything with it.

[PhilProcarioJr]

@Anonymous

I to deal with the exact same problems you do so I feel your pain.

To be perfectly honest Fusion is not good at handling large assemblies, files with a large number of unstitched patches.

I know at some point they will address this but it is a long ways off into the future and who knows exactly when that will be.

We left Fusion for this and many other reasons. Fusion is marketed towards an audience it can't support.

For startups with small assembly needs, hobbyists sure it's a great fit, but for people with needs like yours and mine it's not.

The safe working range from all my tests with Fusion is under 400 parts...granted that number can be more or less depending on the complexity of parts.

A word of caution, be very careful importing files from other CAD apps as I have run into dirty surfaces a lot.

[cekuhnen]

@Anonymous

Hi Andy,

the problem you face (or we face in ID) is simply the way how geometry was build.

Sometimes the quality is as you noticed not good.

There are only two options: rebuild it cleanly or try to sort through existing surfaces remove non function elements and fix the rest.

Rhino is not a bad app for fixing this. Simple designs can easily be fixed in Fusion but in areas where you want to rebuild details (filleted edges)

the lack of untrim is a problem for me because the surface extend is not really giving me to surface manipulation control I need for such cases.

On the other side Rhino's fillet tools are also somewhat frustrating to be quite honest as Rhino also can produce a lot of garbage.

Some use Rhino for basic clean up untrim etc and then use a solid modeler for reapplying fillets etc in a faster way.

The main problem for this outcome is often that in the first place the geometry was not made well.

Knowing how to operate a software and how to build good surfaces is not the same.

And since you have no control over that we will remain having the issue to fix the bad stuff we get.

[Anonymous]

This isn't what I'm referring to. Also, Fusion is Much better at removing fillets, and fixing geometry like that, So long as it's only one part at a time. 

The issue here is entire assemblies. Fusion just chokes on them. 

I'm hoping their team takes note that I'm not the only one that would like some workflow solutions for this. 

Currently, we design things in Rhino. But many times we start with someone giving us their previous assembly as Step, or the dreaded iges. (iges doesn't come through joined in Rhino, so it's terrible). You end up with thousands of pieces, and selecting through them in Fusion is a nightmare. This is partly because other than components, there is very little in terms of organization. That's because this is being designed after the model of solidworks/inventor/creo rather than software that is designer friendly.....thus far anyway. I'm hoping they change that a bit, but I'm guessing it's unlikely. 

Creating software from scratch Should allow you to design it in a way that the user doesn't need a workaround to do something....you know, like creating sheet metal, flattening that, building your model on top of that, then bending it again to create a bent model (which does work, but it doesn't work well). 

We had 6 licences, and we're down to 1 that I use primarily just for opening files. When people build model on top of model in Creo and export as step, it exports ALL the models on top of eachother. Importing into Fusion only imports visible.