Turbo-Fan 4000
Page 1 of 4
Operating Instru Safety Notes
Turbo-Fan 4000
Order No. 7249/40
The Turbo-Fan 4000 model impeller has been developed by experienced model flyers as a power plant for electric-powered
semi-scale model jets, and its design reflects the very special requirements of electric power. At the development stage our
aim was to achieve maximum possible static thrust, but combined with optimised efficiency of the ducted fan unit at the
typical airspeed range of electric-powered model jets. We have been able to achieve this by fine-tuning the aerodynamic
efficiency of transitional airflow areas, and by introducing geometrical washout in the rotor and stator blades.
Any current type of electric motor with a diameter of up to 55 mm can be
installed in the unit. The compact external dimensions of 90 x 123 mm
(length x diameter of fan ring), with an overall length of 135 mm, make
installation in the model a straightforward matter, and also ease the problem
of efficient aerodynamic design of the fuselage or engine nacelles.
The first step is to glue the stator / motor mount securely in the fan ring
(outer jacket): slide the stator into the fan ring until the trailing edge of the
stator ends flush with the rear end of the fan ring. Mark the position of the
stator blades on the fan ring using the point of a pin. Withdraw the stator
from the fan ring, and sand the marked areas using fine 400-grit abrasive
paper. Remove all traces of sanding dust, then glue the stator in the fan ring
using
UHU-Plus Endfest
(24-hour epoxy). Apply a fine fillet of
UHU-Plus
Endfest
around each stator blade to ensure that the stator is firmly fixed to
the fan ring.
The impeller mounting ring can now be glued around the outer fan ring. The
distance between the mount and the front edge of the fan ring will vary
according to your particular model. Before gluing
the mounting ring, sand the joint area of the fan
ring using 400-grit abrasive paper; glue the parts
together permanently using
UHU-Plus Endfest.
The impeller can now be screwed to the model
by means of the three mounting ring lugs.
We have found the WIHA 334 T-handle allen key
to be a very effective tool for installing the rotor.
The rotor can now be fitted, but only after you
have carefully and accurately installed the motor.
De-grease the motor shaft, and clean the bore of the driver (taper collet) using lighter fluid or acetone.
Don’t touch these parts with your fingers after cleaning them.
Make sure all electrical connections to the impeller unit are isolated before continuing with assembly.
Slide the rotor onto the motor shaft as far as it will go, then pull it back by
about 1 mm and hold the rotor temporarily using two fingers (see photo).
Apply the allen key and
lightly
tighten the rotor.
Take care not to exert any force on the rotor blades while you do this.
Now check with the greatest care that the rotor is free to spin, with
absolutely no hint of fouling or rubbing at any point.
