tetrahedron place holder

place holder
my general use. Webspace for discussions.

https://www.thingiverse.com/make:603033

https://www.thingiverse.com/make:275597

alternate core to
Helicopter Cube by SOS1
Published on May 17, 2019
https://www.thingiverse.com/thing:3637534

insert M3 nylock nuts in the core.
Use M3x20 screws.