ok, since there is no proper tutorial on this, i shall show you:

step 1:
look at my lovely Z-10

step 2:
go to export as model file (like exporting anything):

step 3:
before you finalize the export, you need to edit the code seen here:

step 3a:
replace this line

with this:


step 3b: scroll down to the first main rotor line, replace it with this:

it should look like this:

step 3c: do the same with the first heli tail rotor line

should look like this:


step 4: finalising the correct tail code so your choppers tail doesn't become an "inhuman cutting drone"
NOTE: this part is tricky, locate your helicopters tail rotor position, not the offset though. copy each x,y,z position to the designated code:

also, the Y code, do not include the negative -, that just fucks things up.
it shall look like this: