RCRCM MiniVec Dorado Instuction Manual page 3

Now let's prepare the fuselage for the ballast tube.
Glue some 80 grit sand paper to some 19mm dowel. If you don't have any dowel to
hand, then you can just wrap some 80 grit paper around the actual ballast tube and
secure it at one end with a wrap of masking tape. Use this to lightly sand the inside of
the fuselage for the length of the ballast tube. Also, use some loose 80 grit sand
paper to prepare the inside of the canopy area for gluing in the servo tray.
We need to create a reference mark on the ballast to make sure that it is glued in the
right place. Measure 111mm from the inside of the rear stopper in the ballast tube,
and make a mark around the tube. This will align with the REAR edge of the wing
joiner hole. This will put the tube directly centred on a CG of 80mm. Test fit the tube
to the fuselage. Make sure that the tube sits well into the top spine of the fuse and
leaves the wing joiner hole completely clear.
Tape your elevator and rudder snakes in the nose area so that they run just under
the wing joiner hole. This is important - gluing the ballast tube in sets their position to
a degree.
Turn the fuse upside down and make a cradle from a card box to hold it in position.