CADs, how do they work?

A project log for Spine desk lamp

a project for my work-from-home desk, with CNC cut profiles, addressable LEDs, with tentacle kinematics

sebsplanesebsplane 12/10/2020 at 19:470 Comments

From Blender ..

As soon as this idea popped up in my head , i had to immediately materialize it somewhere. It happens that i've been occasionally using blender for more than 10 year now and i'm familiar with a lot of its shortcut to model objects::
With this first model i totally forgot about the basic principle of the tentacle : it has to have a central shaft to be articulated! Plus the spines are upside down,  and the spine profile lacks in details, but at least it gave me an idea of how it could look...

To freecad...

So how do i translate this into a physical thing i can (automatically) manufacture?

Looks like i need a CAD software! How about freecad? I followed the first tutorial and it seemed very powerful at first :

But thing were a bit complicated on the bezier side: so much things on the toolbar ! Do i need to constrain all the things ? how can i constrain handles? What are those green stuff displayed everywhere? seems to indicate the stiffness of the curve or something...

To Inkscape...

So i decided to work bezier curves with inkscape instead on which i'm much more familiar. After a quick svg import, i managed to generate a tool path for my snowflake and run a simulation , nice !

so i think i can scale this process to get my 24-ish plywood pieces for the lamp! Lets try it ,model everything in inkscape :

and then import it in freecad :

Starting from here things get complicated, for some reason , when i try to convert these shapes to sketches, the axis are inverted ,  i cannot remember the process to make the holes , i need to get back to the tutorial... Same for the toolpath, i have trouble selecting the shapes i want to cut, i dont understand where my tools are saved ...

So much for an intro to CAD !