Parametric design for pen adapter for 3D printing I have this model I created for a little kid who has problems in their hands (muscular and/or skeletal). I was thinking that it would be awesome to release the design so anyone with this problems can 3d print it fairly cheap. I guess that the size of the model would be proportional to the size of the hand, but as you can imaging the hole for the pen will remain the same.

I am still prototyping the model and it´s not the final version, but I am already thinking about this part.

Some pics of the process so you can have an idea.




First picture, from left to right: v.1a @ 105%, v.1a @ 100%, v.2a @ 105%,v.2 @ 100%

Last picture is the newest version (v.2a, yellow ones were too big but sort of ok for my big hand to test and improve.

Thanks everybody in advance

EDIT: I attached everything here:
I understand your problem to be:
"How do I make this model parametric, so people don't need to change vertices in order to adapt it to their physiology"

Here I have a few pointers:


The question of the pen is probably the easiest solution: Create a mesh for a pen and use a boolien modifier to create the hole. Each grip can be scaled but the hole for the pencil will remain the same size.
Unless blender implements an node based modelling toolkit in the near future, your toolkit in order of ease to use consists of:


shape-keys Morph targets: A sphere shape turning into a cylindrical unwrapped sphere shape
boolean modifiers
scripts