I'll start by introducing myself as I am new to this forum.
I started launching rockets when I was 13yo and continued until around the age of 16. I have never owned a kit and never really want one, the whole idea of building from scratch was 75% of the appeal to me. during these three years I had a lot of failures and a couple of wonderful successes.
I have only used estes engines (mainly D)
Which brings us to my question... is there an ideal minimum weight for the rocket for each type of engine? I currently have a rocket designed (using openrocket) which is 140g, would it be ok to shove a D12 in a rocket so light?