The world's most advanced fembots are designed in FreeCAD

Show off your FreeCAD projects here!
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
Hypercube3D
Posts: 15
Joined: Sun Aug 23, 2020 12:50 pm

The world's most advanced fembots are designed in FreeCAD

Post by Hypercube3D »

The world's most advanced fembots are designed in FreeCAD :shock:

fem1c2b.jpg
fem1c2b.jpg (89.65 KiB) Viewed 6550 times

The model was created in open source MakeHuman - http://www.makehumancommunity.org/
In the top row of MakeHuman menu, there is option to enable smooth.
What that does is export in quad mesh format.
This is vital.
But be aware that not all poses and adjustment to body features result in a fully qualified quad mesh free of intersecting face problems.
Save the file as .obj.
Then import the .obj file into open source Blender (https://www.blender.org/) and edit the mesh to remove eyes, seal up eye and mouth opening.
Be careful to only use quad faces.
If after cutting mesh you are left with odd number of faces, then use edge subdivision on one edge to ensure there are enough edges for new faces so that they are all quads.
And be also extra careful not to let quad faces intersect each other. If they are intersecting, move the vertexes into a more round flat shape and then they won't intersect when they are filled with faces.
Then export the .obj file.
At this point FreeCAD can import the .obj file and convert to solid - but it does it so horribly wrong by changing the mesh into triangles and takes forever. The resulting step files are prone to geometry errors.

So I admit to being forced into using Fusion360 to import the .obj file and converting to .STEP file. :twisted:

[What can make this workflow better is the conversion of quad mesh into T-spline and conversion of the T-spline into BREP in one go with auto repair of the mesh wherever there are intersecting faces. Its very very difficult to do that as the software world catches up with the complexities of doing this. May be closed sources companies and 3D scanner companies can pool their resources to fund an open source library for this because its bigger than them and without it, endless hours to endless CPU cycles are wasted as the model fails in the final stages.]

Then the STEP file is imported into FreeCAD (https://www.freecadweb.org/).

The model is cloned in the draft workbench and scaled.
Using the Part Workbench, split the model into head and body using the Slice Apart tool.
The head can then be hollowed out using the Part Workbench Thickness tool.
The thickness was set to 2mm and printed it on an Ender 5 plus using 1mm nozzle.
Cura was used as slicer and adaptive layer height was turned on along with tree option for supports.
The result is a semi flexible hollow 2mm thick head for about 600 grams of filament.
After removing supports, it is about 500 grams.

fembot2.jpg
fembot2.jpg (112.86 KiB) Viewed 6550 times

Hollowed out body shell fragments are made the same way using Part Workbench Slice Apart tool and Part Workbench Thickness tool.

The results are visually stunning.

humanoid_finger_parts2.jpg
humanoid_finger_parts2.jpg (114.1 KiB) Viewed 6550 times

What we have here are hollow body shell fragments ready to make into functional humanoid robots.

humanoid_palm_wrist2.jpg
humanoid_palm_wrist2.jpg (141.5 KiB) Viewed 6550 times

The next steps are to print grey parts in plastic, while the gold parts printed in TPU soft materials.
It is easy R&D to create and instantly accessible for everyone.

What I like most is that robots can now be scaled to miniature and 3D print to use smaller motors to test out robotic mechanisms before scaling up. :D

If you are not interested in the workflow, there is a downloadable human model by J Brown here: https://grabcad.com/library/generic-hum ... ody-step-1
His workflow different: https://grabcad.com/library/generic-hum ... ody-step-1

Storage technology has advanced a lot.
It is possible to give humanoid robots 100 years of memory and let them become precious.
I will move my passwords into a machine to help it become a digital twin.
With WiFi & 5G connectivity, it will report its location and what it sees if it has questions.
With LTO battery pack, it should recharge in 6 minutes.
The same battery can jump start an old motor or help drive an electric car for 5 minutes.

So much of it easy to do with open source freedom. :D

Attached is a sphere example of how the orange and grey parts were cut using Part > Split Apart tool:
sphere2b.FCStd
(505.06 KiB) Downloaded 105 times
Last edited by Hypercube3D on Tue Jul 20, 2021 11:45 pm, edited 8 times in total.
paullee
Veteran
Posts: 5092
Joined: Wed May 04, 2016 3:58 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by paullee »

:shock: Jawdropping!
User avatar
Pauvres_honteux
Posts: 728
Joined: Sun Feb 16, 2014 12:05 am
Location: Far side of the moon

Re: The world's most advanced fembots are designed in FreeCAD

Post by Pauvres_honteux »

:o A-M-A-Z-I-N-G !!! :o
User avatar
Pauvres_honteux
Posts: 728
Joined: Sun Feb 16, 2014 12:05 am
Location: Far side of the moon

Re: The world's most advanced fembots are designed in FreeCAD

Post by Pauvres_honteux »

... and such a model as a crash dummy would be just jaw-dropping!
Especially if one could change its main dimensions directly in FreeCAD.

This could possibly be one of the first ones:
Jack human modeling
Using Transom Jack in the Human Engineering Analysis

It could be they are the ancestors to what CATIA use in their program today.
We use it to check available space around it when seated and stepping in/out plus reaching stuff in the coupé.
The workshop use it for checking postures when assembling them vehicles.
un1corn
Posts: 237
Joined: Sat Dec 26, 2015 2:06 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by un1corn »

Brilliant work. :shock:
jeno
Veteran
Posts: 1802
Joined: Sun Jun 29, 2014 10:41 am

Re: The world's most advanced fembots are designed in FreeCAD

Post by jeno »

Hypercube3D wrote: Fri Jul 16, 2021 1:03 pm The world's most advanced fembots are designed in FreeCAD :shock:
...
This is vital.
But be aware that not all poses and adjustment to body features result in a fully qualified quad mesh free of intersecting face problems.
Save the file as .obj.
Then import the .obj file into open source Blender (https://www.blender.org/) and edit the mesh to remove eyes, seal up eye and mouth opening.
Be careful to only use quad faces.
If after cutting mesh you are left with odd number of faces, then use edge subdivision on one edge to ensure there are enough edges for new faces so that they are all quads.
And be also extra careful not to let quad faces intersect each other. If they are intersecting, move the vertexes into a more round flat shape and then they won't intersect when they are filled with faces.
Then export the .obj file.
At this point FreeCAD can import the .obj file and convert to solid - but it does it so horribly wrong by changing the mesh into triangles and takes forever. The resulting step files are prone to geometry errors.

So I admit to being forced into using Fusion360 to import the .obj file and converting to .STEP file. :twisted:
...
To shorten things up, it is much better to work with fbx-format. It supports quads. Export from Blender to fbx. Use Cad Assistant to import the fbx (the free version is fine). Save it in Cad Assistant as BREP-file. You can import BREP directly in Freecad. All quads stay alive.
screenshot of BREP-import of an fbx-file in freecad
screenshot of BREP-import of an fbx-file in freecad
fbxtobrep.png (313.77 KiB) Viewed 6145 times
Kind Regards
Hypercube3D
Posts: 15
Joined: Sun Aug 23, 2020 12:50 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by Hypercube3D »

jeno wrote: Sun Jul 18, 2021 8:30 am To shorten things up, it is much better to work with fbx-format. It supports quads. Export from Blender to fbx. Use Cad Assistant to import the fbx (the free version is fine). Save it in Cad Assistant as BREP-file. You can import BREP directly in Freecad. All quads stay alive.
It seems to import OK, but when I check scale, its x1000 and impossible to scale or do decent operations such as export as STEP or cut with the Part > Slice Apart tool (crashes). Tried under different OS and versions of FreeCAD with something as simple as a sphere generated in blender + repaired top and bottom into quad faces (still crashes). Workflow ok with f360 (but not perfect as shapes get more complex).
sphere2.blend.zip
(103.13 KiB) Downloaded 104 times
I have doubt about the quad faces showing in import - seems the whole idea of T-splines and smooth infinite resolution surfaces lost because it still seems like a polygon mesh made solid. (I know this transition from mesh to T-spline based STEP conversion is computationally extremely difficult and software world still has to catch up - so I'm not complaining - just pointing out the differences and grateful for whatever can work today :D .)
Last edited by Hypercube3D on Sun Jul 18, 2021 11:20 am, edited 1 time in total.
keithsloan52
Veteran
Posts: 2753
Joined: Mon Feb 27, 2012 5:31 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by keithsloan52 »

Hypercube3D wrote: Fri Jul 16, 2021 1:03 pm
So I admit to being forced into using Fusion360 to import the .obj file and converting to .STEP file. :twisted:
I have a similar requirement to be able to go from Blender with a mixture or Quad Triangles to GDML Tessellated.
I have added a facility to import an OBJ file with Quads/Triangles to the GDML Workbench https://github.com/KeithSloan/GDML.

That is if you perform FreeCAD | Open | File which is an Obj and you have the workbench installed you get prompted with
8731E5A5-185C-4BD7-8086-143968851F16_4_5005_c.jpeg
8731E5A5-185C-4BD7-8086-143968851F16_4_5005_c.jpeg (26.37 KiB) Viewed 6085 times
I have tested with some simple files
humanoid_quad.obj
(2.89 KiB) Downloaded 100 times
humanoid_tri.obj
(3.24 KiB) Downloaded 108 times
ABA3E604-143E-4FD5-86B1-7DD967A5CA61.jpeg
ABA3E604-143E-4FD5-86B1-7DD967A5CA61.jpeg (49.37 KiB) Viewed 6085 times
And I can then export as STEP or GDML
humanoid_quad1-GDMLTessellated.step
(130.99 KiB) Downloaded 95 times
But there are some bugs for larger files (Also slow performance)

Wondering if some kind soul could produce some smaller test OBJ files that fail and would hopefully make debugging easier.
Hypercube3D
Posts: 15
Joined: Sun Aug 23, 2020 12:50 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by Hypercube3D »

keithsloan52 wrote: Sun Jul 18, 2021 11:17 am
Wondering if some kind soul could produce some smaller test OBJ files that fail and would hopefully make debugging easier.
Here are a whole bunch of the same sphere that started in blender and ended up in FreeCAD sliced and hollowed out and many of the file types talked about in this thread.
sphere2.zip
(1022.24 KiB) Downloaded 109 times
keithsloan52
Veteran
Posts: 2753
Joined: Mon Feb 27, 2012 5:31 pm

Re: The world's most advanced fembots are designed in FreeCAD

Post by keithsloan52 »

Hypercube3D wrote: Sun Jul 18, 2021 11:31 am
keithsloan52 wrote: Sun Jul 18, 2021 11:17 am
Wondering if some kind soul could produce some smaller test OBJ files that fail and would hopefully make debugging easier.
Here are a whole bunch of the same sphere that started in blender and ended up in FreeCAD sliced and hollowed out and many of the file types talked about in this thread.
sphere2.zip
Thanks but the sphere.obj loads just fine and I can export as GDML or STEP
F2ACD15D-F7EB-4B4A-BEB2-EC4C09B67A9E.jpeg
F2ACD15D-F7EB-4B4A-BEB2-EC4C09B67A9E.jpeg (71.76 KiB) Viewed 6058 times
8A9A47F6-230D-4263-8879-284C2044F770.jpeg
8A9A47F6-230D-4263-8879-284C2044F770.jpeg (40.87 KiB) Viewed 6058 times
I tried with an OBJ file produced by MakeHuman ( > 1.4 Meg ) and it fails on load, was hoping to find
a smaller file that fails.
Post Reply