Help Exporting STL file from Step Import

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Frosttoys
Posts: 3
Joined: Tue Sep 25, 2018 5:56 pm

Help Exporting STL file from Step Import

Postby Frosttoys » Tue Sep 25, 2018 6:10 pm

Hello Freecad Community,

I am having an issue where the STEP file I had sent to me from solidworks will not export to an STL cleanly. I believe the issue is that the model is in sub assemblies and the STL export script doesn't know how to deal with that. When exported the STL file which is opened in CURA/Simplify3d is "exploded", as in parts are randomly strewn across the build area. I have attempted OBJ export as well with identical results. The end result is to 3D Print this model.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13528 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 5c3f7bf8ec51e2c7187789f7edba71a7aa82a88b
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
Attachments
Tree.PNG
Tree.PNG (32.88 KiB) Viewed 510 times
Result.PNG
Result.PNG (142.01 KiB) Viewed 510 times
Model.PNG
Model.PNG (205.7 KiB) Viewed 510 times
oldmachine
Posts: 241
Joined: Wed May 31, 2017 11:49 pm

Re: Help Exporting STL file from Step Import

Postby oldmachine » Tue Sep 25, 2018 10:07 pm

Having come to FreeCAD from SolidWorks, I've done this a bazillion times.

Here's the scoop:

An Assembly was exported from SW as a Step file. So, import all the files into FreeCAD.

Open FreeCAD, Open the PartDesign Workbench and Create a new File and a Part. (the Yellow icon)
Also create a Body inside the Part you just created. (the Blue icon). You won't use the Body now but, as a SW user, you'll come to appreciate doing it as matter of similarity. The Boolean result gets placed inside the Body.
Import the Assembly Step file (it will load all the sub files as you show)
(Assuming all the step files are correctly defined in space in SW), they should retain they're place in space in FreeCAD)

Now, Two Options:
1) Can select all the subfiles and export an STL. They will properly import into Simplify3d and Slic3r*

2) Can select all the subfiles and locate in the PartDesign menubar, Boolean Operation. Select 'Fuse' at the bottom of the panel. You'll now have one single part.
Select it and export as STL.

In both cases, the STL will be a single part.

IMPORTANT*
In Simplify3d and Slic3r (and Cura but, I don't have so can't be sure), UNcheck the AutoArrange!!

Example of each (screenshot)
MAC OSX Sierra
3D Parts & Links (made using FreeCad and Solidworks): https://www.thingiverse.com/Still_Breathing/designs
Android App & Links: https://play.google.com/store/apps/deta ... .bestknots
chrisb
Posts: 25681
Joined: Tue Mar 17, 2015 9:14 am

Re: Help Exporting STL file from Step Import

Postby chrisb » Tue Sep 25, 2018 10:11 pm

Why do you use PartDesign for this? It looks rather like a Part operation and you don't use anything else from PartDesign. I didn't try it with booleans, but PartDesign operations usually have much more overhead.
oldmachine
Posts: 241
Joined: Wed May 31, 2017 11:49 pm

Re: Help Exporting STL file from Step Import

Postby oldmachine » Tue Sep 25, 2018 10:16 pm

Having come to FreeCAD from SolidWorks, ProEngineer, Inventor... other, using PartDesign with it's arrangement of sketches and Pad/Cut/Etc, similarity between those other programs is maintained for sensible design process - if you know one, you basically know the others including FreeCAD/PartDesign.

Sure, you can do it in Part workbench... but, I've taught too many engineers and come away with a standard modus operendi...

Oh, true nothing else was used in PD for this example but, usually I add features to the imported Step and doing it in PD makes it simple for my little brain.

Followup:

File size comparison:

Freecad Exported cylinder, base and rectangle: 16kb
Freecad Exported Boolean: 16kb
Freecad file with Boolean op and Step files: 14kb The Winner :D
SolidWorks Assy: 137kb
SolidWorks Exported Step (select the 3 parts): 32kb
SolidWorks Exported Assy Step: 52kb
MAC OSX Sierra
3D Parts & Links (made using FreeCad and Solidworks): https://www.thingiverse.com/Still_Breathing/designs
Android App & Links: https://play.google.com/store/apps/deta ... .bestknots
Frosttoys
Posts: 3
Joined: Tue Sep 25, 2018 5:56 pm

Re: Help Exporting STL file from Step Import

Postby Frosttoys » Wed Sep 26, 2018 3:31 pm

oldmachine wrote:
Tue Sep 25, 2018 10:07 pm
Having come to FreeCAD from SolidWorks, I've done this a bazillion times.

Here's the scoop:

An Assembly was exported from SW as a Step file. So, import all the files into FreeCAD.

Open FreeCAD, Open the PartDesign Workbench and Create a new File and a Part. (the Yellow icon)
Also create a Body inside the Part you just created. (the Blue icon). You won't use the Body now but, as a SW user, you'll come to appreciate doing it as matter of similarity. The Boolean result gets placed inside the Body.
Import the Assembly Step file (it will load all the sub files as you show)
(Assuming all the step files are correctly defined in space in SW), they should retain they're place in space in FreeCAD)

Now, Two Options:
1) Can select all the subfiles and export an STL. They will properly import into Simplify3d and Slic3r*

2) Can select all the subfiles and locate in the PartDesign menubar, Boolean Operation. Select 'Fuse' at the bottom of the panel. You'll now have one single part.
Select it and export as STL.

In both cases, the STL will be a single part.

IMPORTANT*
In Simplify3d and Slic3r (and Cura but, I don't have so can't be sure), UNcheck the AutoArrange!!
I must be doing something wrong as the boolean operation keeps failing with the error "Fusion of tools failed, Internal name: Boolean". I can't attach the step file or the FCSTD files as they are too large, am I allowed to put it on a transfer server and put the link here or is that bad?
oldmachine
Posts: 241
Joined: Wed May 31, 2017 11:49 pm

Re: Help Exporting STL file from Step Import

Postby oldmachine » Wed Sep 26, 2018 4:11 pm

First, verify all is good by doing a simple test.
Attached are the three individual part step files and the assembly step - go thru the process I laid out and see what happens...
Then, Also attached is the Freecad file without the boolean op
MAC OSX Sierra
3D Parts & Links (made using FreeCad and Solidworks): https://www.thingiverse.com/Still_Breathing/designs
Android App & Links: https://play.google.com/store/apps/deta ... .bestknots
Frosttoys
Posts: 3
Joined: Tue Sep 25, 2018 5:56 pm

Re: Help Exporting STL file from Step Import

Postby Frosttoys » Wed Sep 26, 2018 4:56 pm

oldmachine wrote:
Wed Sep 26, 2018 4:11 pm
First, verify all is good by doing a simple test.
Attached are the three individual part step files and the assembly step - go thru the process I laid out and see what happens...
Then, Also attached is the Freecad file without the boolean op
That seems to have worked, There is an error that popped up finally on my model that says there is a non-boolean object. How might one resolve this without re-drafting it?
oldmachine
Posts: 241
Joined: Wed May 31, 2017 11:49 pm

Re: Help Exporting STL file from Step Import

Postby oldmachine » Wed Sep 26, 2018 5:02 pm

Without your file, I am unable to help resolve the Boolean error.

Try copying the bad boolean file (paste somewhere).

With the bad bool gone, see what happens.

Then, in a new file, open the bad bool and investigate...
MAC OSX Sierra
3D Parts & Links (made using FreeCad and Solidworks): https://www.thingiverse.com/Still_Breathing/designs
Android App & Links: https://play.google.com/store/apps/deta ... .bestknots