Quick and dirty code with few protections.
Print in vase mode with some not to brittle plastic
Don't go crazy with radius .
As usually i appreciate reports of successful prints especially in flex type materials .
x = 25; // bellows inner measurement
y = 50; // bellows inner measurement
approx_z = 100; // bellows relaxed height without sleeves
steps = 10; // number of folds
step = round(aprox_z / steps);
z=step*steps; // exact height
ext = 1.5; // fold horizontal extension multipler
radi = 1; //
verticalsegment = 0.2; // vertical segment between folds
sleeve = 20; // Sleeve at ends
sleeve_ext = 0; // Sleeve horizontal extension (multiplied by sleeve value added to x/y)
sleeveFN = 20; sides of sleeve