Mecabricks Editor - Need help w. hinge design

[Chickeenz]

Hello Eurobricks! First time poster here. 

Im in the midst of making my own model of a spaceship from an older anime. (3D rendering of the ship by Renan Longatti   https://www.artstation.com/artwork/EW1KN ) 

Now, i've made the main bulk of the engines and moved on to the cockpit part - my problem is i cannot figure out to make a sturdy enough hinge design for the various 'flappy' parts on the engine cover, while keeping the scale uniform with the stationary parts without having too much bulk ie. making the engines too bulky/wide, and I'd hate to remake the model for scaling problems again (Have already done this once so far)

I've troubleshooted on my own for a weeks time now and think i'm beginning to go blind for possibilities myself.  

I have a relatively clean model up on mecabricks that people can play with, and if someone could help i'd really appreciate it. 

Model on mecabricks: https://www.mecabricks.com/en/models/b82xKJ71a1z  

A final thing to keep in mind - my plan is to complete the model and buy all parts when done and assemble irl so everything have to be correctly put together(no cheating for 'looks' sake) 

Thanks in advance - feel free to ask for further info or otherwise, I'll reply asap :-)