"Flexible" Parametric Coupler

I'm designing this parametric coupler for use with coupling any motor to any shaft fairly easily. I'm specifically going to be using to for coupling nema 23 shafts 7 mm shafts to M8 threaded rod. I also wanted something for the future when i switch to leadscrews. I will be developing this to handle the power required and so i can use it later on. The stl is for 7mm to 8mm couling. You can also change the bolt size,overall length, input and output shaft sizes in the scad file.