Cool spool holder! Great it's working out for you. It's always satisfying when your project works the way you want it to go.
OpenSCAD sounds cool - I think I heard about it from one of my group mates before of a similar concept where you code rather than by drawings, but, man, I must visualise what I'm doing with my project. I currently use Fusion 360 with my projects - free for start-ups and enthusiasts (for now at least!).
I have to admit it sounds a bit weird to "code" a 3d part, but it is really powerful. From a person like me who learned C, it's easy to conceptualize a part as a flexible module you can call in a bigger project, like we usually build a complex program in C.
The OpenSCAD editor allows real-time visualization of what you're doing/coding, so it is not so hard to see where you're going while coding.