Feature problems with STEP - break instance or history ?

[Anonymous]

Hi everyone,

Kind of new to the F360 world so this might be a normal fix but I haven't found anything online, or rather I barely know how to search for it. Hoping to get some help here:)

I've imported a STEP file from Grabcad of a bicycle and would now like to modify it. (attaching images)

Somehow when applying a CUT feature for example it generates the cut in circular pattern and/or mirror..

Almost feels like I'm modelling in the "past" and I can't wrap my head around it. It's like having a "future" pattern/mirror automaticly applied after doing somehting.

As you can see it duplicates/mirrors the rectangle cut on the front wheel too, and also "circular pattern" the cut on the back wheel..

I'm going bonkers.

I'm a SolidWorks boomer, maybe I've just haven't understood somehting very simple in th F360 workflow, and appologize if that is so.

Running 2.0.9512 on WIN 10

Thanks guys and gals!

Henrik

[g-andresen]

Hi,

Please share the file.

File > export > save as f3d on local device  > attach it to the next post.

günther

[TrippyLighting]

What you are experiencing is the difference between a copy and an instance.

The wheels are instances and the individual spokes also appear to be instances. That means there are probably only two data sets holding geometry. One for the rim and one for the spoke. So if you modify one wheel, and one spoke that modificaton applies to both wheels and all spokes.

That isn't unique to Fusion 360, it aplies to all CAD and 3D modeling software I am aware of.

Also, there is a  camera button above the text field for creatng editing a post. You can also simply drag & drop images from a folder or your desktop into a post right in the browser 😉

[TheCADWhisperer]

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@Anonymous wrote:

(attaching images)

I'm a SolidWorks boomer, ...

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There is no difference between SolidWorks and Fusion.

Complete the Extrusion and Attach your file here so that we can see what you did.

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[Anonymous]

Hi and thanks,

attaching the file!

[Anonymous]

Thanks Peter,

So strange that I've never came across this before..

Is there any way to break that connection ? I mean, just to have a 3D model as is, and be able to to work on it.

And cheers, saw the camera;)

Henrik

[TrippyLighting]

Not when using just Fusion 360, unfortunately. I know this exists in ZW3d and I am pretty sure it exists in Solid Works (just don't remember) and Autodesk Inventor. When you export it asks you if you want to export it into part or an assembly.

When you choose "part" (in ZW3D) it creates a flat structure with solid bodies, which then are copies and not instances.

[Anonymous]

Yeah that sounds like what i used to do in SW, save as "part" and good to go.

Just find it so strange that I'm stuck with a cad model that has a "living memory" and can't me modified, can't be killed.

Amazing

[TrippyLighting]

Can you provide a link to the grabcad model ?

[Anonymous]

Here!

https://grabcad.com/library/road-bike-motobecane-1 

[kb9ydn · Accepted solution]

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@TrippyLighting wrote:

What you are experiencing is the difference between a copy and an instance.

The wheels are instances and the individual spokes also appear to be instances. That means there are probably only two data sets holding geometry. One for the rim and one for the spoke. So if you modify one wheel, and one spoke that modificaton applies to both wheels and all spokes.

This is exactly correct.  When you import the step file it creates a rim part and a spoke part, which are then "copied" as needed in the front and rear wheels assemblies.  By "copied" I mean that each copy of a spoke or rim is linked back to the original source part.  In computer science (and probably other fields too) this is known as an "instance".  (I only point this out because not everyone may be familiar with the difference between an instance and a copy.  And in fact I think the word copy is insufficient on its own to distinguish the difference.  I.E. a copy of a part could be linked to the original part or not.  But I'm getting pedantic so I'll stop here.)

Anyway in Solidworks what you would do is to make one of the copies (instances) independent, which would save it under a different file name (or just rename it if it's a virtual part).  I'm not aware of a way to do this in Fusion directly with a single command.  Probably the easiest method would be to create a new component and just copy the body you want into it.

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