Help with 3D Printing

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KevCan
Posts: 4
Joined: Tue Jul 31, 2018 6:38 am

Help with 3D Printing

Postby KevCan » Tue Jul 31, 2018 7:33 am

Hello! My first post, and forgive me first as I'm new to FreeCad (and Posting in Forums generally) - your patience and understanding appreciated in advance!!

I've created a part in FreeCad, and sent it to a 3D printing company. The company tells me that the part fails to print correctly, and they are not sure why. They asked me to inspect my files and see if anything is wrong there. I've done that and to me, all looks fine, but wondering if a more expert eye might notice something that I've missed. So my questions are:

1) Is this the right place to ask that question (and if not, can you point me in the right direction)
2) Any ideas as to what may be causing the print to fail?

I've uploaded three files: A screen shot of how the part should look;a photo of how the part looks once printed; the Alias Mesh file as exported from FreeCad.

If it's not clear from the pictures - the clasp in the centre of the part prints as a mess!

Any tips or ideas appreciated.

Thanks, Kev
Attachments
LGD.obj
Alias Mesh exported from FreeCad
(297.31 KiB) Downloaded 10 times
LGD - Failed Part.jpg
Photo of Failed Part
LGD - Failed Part.jpg (31.15 KiB) Viewed 309 times
LGD - FreeCad ScreenShot.png
ScreenShot of how the part should look
LGD - FreeCad ScreenShot.png (90.8 KiB) Viewed 309 times
chrisb
Posts: 19455
Joined: Tue Mar 17, 2015 9:14 am

Re: Help with 3D Printing

Postby chrisb » Tue Jul 31, 2018 8:23 am

Hi Kev, welcome to the FreeCAD forum
KevCan wrote:
Tue Jul 31, 2018 7:33 am
1) Is this the right place to ask that question (and if not, can you point me in the right direction)
No, Open discussion is not the right place, I moved your post to the Help forum. Here in Help forum you see an "IMPORTANT: ..." link at the top, please follow it and publish your FreeCAD info here.
KevCan wrote:
Tue Jul 31, 2018 7:33 am
2) Any ideas as to what may be causing the print to fail?
To analyze your model we rather need the FreeCAD file with the extension .fcstd, not the exported mesh.
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fosselius
Posts: 346
Joined: Sat Apr 23, 2016 10:03 am

Re: Help with 3D Printing

Postby fosselius » Tue Jul 31, 2018 11:40 am

Screenshot from 2018-07-31 13-38-25.png
Screenshot from 2018-07-31 13-38-25.png (87.41 KiB) Viewed 282 times
Screenshot from 2018-07-31 13-38-33.png
Screenshot from 2018-07-31 13-38-33.png (9.88 KiB) Viewed 282 times
I opened the .obj file in Slic3r that I use for my 3d printer and everything looks just fine.
User avatar
easyw-fc
Posts: 2687
Joined: Thu Jul 09, 2015 9:34 am

Re: Help with 3D Printing

Postby easyw-fc » Tue Jul 31, 2018 12:41 pm

KevCan wrote:
Tue Jul 31, 2018 7:33 am
Hello! My first post, and forgive me first as I'm new to FreeCad (and Posting in Forums generally) - your patience and understanding appreciated in advance!!

I've created a part in FreeCad, and sent it to a 3D printing company. The company tells me that the part fails to print correctly, and they are not sure why. They asked me to inspect my files and see if anything is wrong there. I've done that and to me, all looks fine, but wondering if a more expert eye might notice something that I've missed. So my questions are:

1) Is this the right place to ask that question (and if not, can you point me in the right direction)
2) Any ideas as to what may be causing the print to fail?

I've uploaded three files: A screen shot of how the part should look;a photo of how the part looks once printed; the Alias Mesh file as exported from FreeCad.

If it's not clear from the pictures - the clasp in the centre of the part prints as a mess!

Any tips or ideas appreciated.

Thanks, Kev
I opened your obj in 3d builder on Win and I found issues... I'm attaching what the sw has repaired...
PS I'm not familiar with 3d printing at all...
LGD-repaired.obj
(280.22 KiB) Downloaded 8 times
KevCan
Posts: 4
Joined: Tue Jul 31, 2018 6:38 am

Re: Help with 3D Printing

Postby KevCan » Tue Jul 31, 2018 7:36 pm

chrisb wrote:
Tue Jul 31, 2018 8:23 am
I moved your post to the Help forum. Here in Help forum you see an "IMPORTANT: ..." link at the top, please follow it and publish your FreeCAD info here.
Thanks for the welcome and the tips. I didn't spot the new post in the help forum, but probably I didn't check hard enough! Either way, I see what I need to do to get help efficiently, what I need to include in the post etc. Thanks for pointing me in the right direction!


fosselius wrote:
Tue Jul 31, 2018 11:40 am
I opened the .obj file in Slic3r that I use for my 3d printer and everything looks just fine.
Thanks Fosselius - appreciate you checking for me. I'll use the new post in the help forum to add new files in case that's more helpful


easyw-fc wrote:
Tue Jul 31, 2018 12:41 pm
I opened your obj in 3d builder on Win and I found issues... I'm attaching what the sw has repaired...
PS I'm not familiar with 3d printing at all...
Awesome, thanks for that, much appreciated. I'll download the file and check it out. Out of interest, was it clear to you what the error was, or what was changed?
chrisb
Posts: 19455
Joined: Tue Mar 17, 2015 9:14 am

Re: Help with 3D Printing

Postby chrisb » Tue Jul 31, 2018 8:08 pm

Now it is in the help forum. If you upload the FreeCAD file we might find the source of the problem so that you can avoid the problems in the future.
KevCan
Posts: 4
Joined: Tue Jul 31, 2018 6:38 am

Re: Help with 3D Printing

Postby KevCan » Tue Jul 31, 2018 8:54 pm

chrisb wrote:
Tue Jul 31, 2018 8:08 pm
Now it is in the help forum.
Ah yes - I've found it now, thank you :)

Here I'm attaching the FreeCad File:
LGD.FCStd
(717.28 KiB) Downloaded 12 times
I've just upgraded to 0.17, but the FreeCad file was created in the old version (0.16) version. I don't want to keep printing the part over and over if there is something obviously wrong with the design that is nothing to do with the version. I don't really want to assume (just yet) that this is the issue. I'm expecting an error on my part rather than the software as I'm new to this.

If there is nothing to find or change with the design, then I'll reproduce the mesh using the latest FreeCad version and ask the printing company to keep trying.

OS: Windows 8
Word size of OS: 64-bit
Word size of FreeCAD: 32-bit
Version: 0.16.6706 (Git)
Build type: Release
Branch: releases/FreeCAD-0-16
Hash: f86a4e411ff7848dea98d7242f43b7774bee8fa0
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17

Thanks again, appreciate the help!
chrisb
Posts: 19455
Joined: Tue Mar 17, 2015 9:14 am

Re: Help with 3D Printing

Postby chrisb » Tue Jul 31, 2018 9:53 pm

Geometry check passes, sketches seem to be ok. One minor point: instead of using a vertical distance of 0mm you should use a horizontal or point on line constraint instead. Similarly the 180° angle can be omitted. So the problem might have been the 3D print process rather than the model. However, it is best to use the latest version for export.

If you would rebuild this model in 0.17/0.18 you would rather model it completely in PartDesign than to switch to and fro between Part and PartDesign. Might be a good exercise.
TheMarkster
Posts: 1061
Joined: Thu Apr 05, 2018 1:53 am

Re: Help with 3D Printing

Postby TheMarkster » Tue Jul 31, 2018 10:12 pm

If you create the mesh in mesh design workbench, using netgen -> very fine the resulting mesh looks okay except for some fold on surface errors, of which the LGD-repaired mesh also still has a few. If you run the analyze -> evaluate and repair mesh tool and set view to wireframe mode (or set transparency in the view tab) you can see where the errors are centered.
folds-on-surface-opt.gif
folds-on-surface-opt.gif (894.1 KiB) Viewed 213 times
chrisb
Posts: 19455
Joined: Tue Mar 17, 2015 9:14 am

Re: Help with 3D Printing

Postby chrisb » Tue Jul 31, 2018 10:18 pm

Interesting, but that's not where the print had the defects.