Modelling a star tetrahedron

Support Modeling
1

Hello, I am a modest noob at blender and I use it for making 3d printable models. I have a challenge and I can’t seem to find a good solution for it. Until now I found a equilateral pyramid stl model and duplicated it until I got the star tetrahedron shape but it was a mess in symmetry and wireframe consistency.

Screenshot (76).png1920×1080 371 KB

Here is the figure I want to end up with:

star-tetrahedron-3.jpg1200×1220 495 KB

Can anyone suggest a easier way to make this shape?

2

check addon for extra mesh for tetrahedron

after go to bl wiki for addons
there is an addon to make wire from edges
don’t remember name will try to find it !

happy bl

3

Hi Horialoan,

I quickly tried several methods for that today. I thought the wireframe modifier could help. But this modifier needs faces to work. Then I tried the skin modifier, which was promising at first. But with a more complex mesh of only edges it gave me weird results. Maybe I was doing it wrong.

But I found this tutorial on Youtube, which is not exactly but quite close to what you want to model.

Hope that helps.

4

Thank you for the suggestions guys, I’m gonna try and give you feedback.

5

So, I tried something that gets close but still it’s not there:

  1. I made a tetrahedron with add mesh - math function - regular solid - tetrahedron
  2. Applied wireframe modifier with thickness .3
    Until now the tetrahedron has some kind triangular edges
    https://drive.google.com/open?id=0B_jwSVrnQA08QWlldzVJbGYzT3M
  3. Made 10 edge loops on each of the 6 edges.
  4. Added Subdivision Surface modifier with 6 view count and duplicated the model.
    Ended up with this:
    https://drive.google.com/open?id=0B_jwSVrnQA08ZXNqNlA5Qy1OV3c
    The edges are still not round.
    https://drive.google.com/open?id=0B_jwSVrnQA08ZXNqNlA5Qy1OV3c
    Tried to get the right angle to rotate the 2nd tetrahedron but it’s a pain in the a*s.
    Another problem is that I can’t easely make the inside wireframe like in the photo from the first post.

Any other suggestions? Should I sculpt it or start from another geometric shape?

6

Here is part of the solution but the wireframe isn’t round. Hope to sort this out and print it soon.

7

look at this one
is it good enough with rounded edges

happy bl

Attachments

zz1.jpg1920×1080 172 KB

8

It looks good, did you make it in blender?

9

yup in 5 seconds

looks like it also does a nice job to convert to mesh with tris.

happy bl

10

just add an octahedron
and use this script here

then convert to mesh

happy bl

11

I added a octahedron and used script
https://drive.google.com/open?id=0B_jwSVrnQA08cjlHd05FUldTMEU
What should I change in the script?

12

forgot there is one other step to be done

see this video

thanks
happy bl

13

Thanks but I can’t see the video

14

what problems for video ?
try following
not certain up to which parts but try the round edges script and see if it gives the right shape

happy bl

Attachments

tetrahe-round1.JPG897×893 64 KB

15

on 3 part
select middle point on one face
then Shift-G and select sake connected edges
to select all middle verts for all faces.

then scale outward

after that I think this is the right shape and you can use round edge script

happy bl

16

Thank you for the help. I found a way to make an orientation that will suit my needs for 3d ptinting the model. I can print it with the polygonal shape tubing that I made earlyer with the wireframe modifier.