Build Articles
HET-RC - FA18 Hornet EDF
By Carl Tulanko
February 15, 2005 - 03:58:53 PM

HET-RC FA-18 Hornet EDF Jet as it comes from Warbirds-RC	It comes very well wrapped with wings and tail feathers taped inside the lids so they won't move. Take care by removing the tape, then they wings and such will come right now	The major components are shown
The model has some small shipping damage, a chipped piece of balsa	The damage was very easily fixed! This is a top quality ARF	Begin construction by sanding the flying stab control wires with 60 grit sandpaper
Wipe away any excess sanding residue with alcohol and towel	Install the washer over the Elevon control wire	Place the washer flush against the fuselage side
Apply masking tape to keep excess epoxy away from the fuselage	Dry fit the flying stab plate	Mix a batch of good quality epoxy
Apply epoxy to the wire and plate, then press the plate over the wire as shown	Apply epoxy inside the flying stab slot for the plate	Install the stab over the plate and position it so it's even with the fuselage sides and flush against the washer
The stabs will "self-bottom" when fully seated over the plate. Clean up the excess epoxy with alcohol and a paper towel	Remove the masking tape	All masking should now be removed

Perform final checks before the epoxy sets, making sure no epoxy wicked into the wire joint	Use a dual conversion receiver for safety	Use Hitec HS-81MG Metal Gear servos or similar for Elevon control
Use a receiver to center the servos, then installl the long horn from the bag. Drill out each horn with a 5/63" bit	Install the supplied EZ connector	Apply some Lok-Tite to the threads of the connector
Measure the horn connector and make sure both sides are the same distance	Set each side to 5/8" from the elbow to bottom of the horn	The knurled nut was a very nice touch. Make sure the unit can spin in the horn without binding, but you don't want any slop either.

A 2-56 nylon clevis is used on each side. Cut two rods so 2 1/4" protruded from the bottom of each clevis

Install the rod in the EZ connector and use a drop of Lok-Tite

Rod assemblies completed. The set screws were shortened a bit for convenience

Test fit the servo... use a piece of medium fuel tubing as a clevis safety	Set the stab to "zero" incidence when installing the servo assembly... it should run parallel with the fuselage	Make a block 65mm high and use the wood block to keep the stab "horizontal"
Install the servo... the receiver was hooked up and turned on along with the transmitter so the servos center before adhering them to the inside	Carefully install each servo, making sure the control rods are parallel to the fuse top	Servos are shown installed. Now is a good time to add the reinforcement mod to the model in the servo area that is shown at the end of this manual
Use a pencil to "find" the guide holes	Open up the guide holes for the wing dowel pins	Use a pencil to mark the wing position on the fudelage

Carefully cut away the covering about 1/16" inside the pencil mark

Make sure you do not to cut too deep

Remove the inside covering

The removed area is exposed

Use a Monokote iron to seal the fresh cut edge

Repeat on the other wing area, trimming as before

Drill 1/8" staggered holes in the fuselage and wing about an inch apart from eachother as shown

Wing holes should be completed as shown

A block was made 65mm high per instructions and used to prop up the wing

Mix up some BVM Glass Mil in with the epoxy to add strength

Apply the epoxy to the wing, ply spar and fuselage side

Wing is shown installed

Use a square to true up the wing, which should be perpendicular to the fuselage side

Make sure the fuselage is square to the table

Allow the epoxy to semi-set like this so it won't all drain to the bottom, but rather sit where it needed to reside, allowing even dispersion. This position also allows easy removal of the excess epoxy with alcohol and a paper towel

Position the fuselage horizontally and measure the inside wing height

Measure the distance of wing tip from the table; it should be the same as the root side distance, 65mm, indicating it was correctly installed with no dihedral

Apply epoxy to the other wing root on the fuselage

Apply epoxy to the wing

Apply a thick coat of epoxy to the wing spar

Install the spar

Apply more epoxy to the outside of the spar

Position the wing for installation

Install the wing in place

Seat the wing flush, then , clean up excess epoxy with denatured alcohol and paper towels	Square up the wing while the epoxy semi-sets	Measure wing distance again ... it should be the exact same height as the other wing
Use the wing block to check inside root and wing tip so that they are both 65mm from the table and are flat on the block.	Wings are shown installed	This is a template that was made for installing the vertical stabs. You can print it and make a jig

Cut out the printout as shown

Use the template to make a 1/8 ply guage

Cut a ply gauge as shown

Mark the vertical stab locations

Remove the covering from the stab area

Removal of the covering will reveal balsa for good glue bond

Use an Iron to seal the edges of the covering

Both Stab areas are shown prepared and ready for installation

Each vertical stab is angled at the bottom... check the bottom to make sure the correct one is used on each side

Mark the stabs left and right so they don't get mixed up

Peel away the excess covering on the stabs before gluing

Vertical stab is shown ready to install

Apply epoxy to the vertical stab

Apply a thin coat of epoxy to the fuselage area

Use the gauge to set the stab angle

Pin the stab at the base while the epoxy sets

Epoxy the second stab in place... Add fillets to the inside seams

Vertical stab installation is now completed

Use a good quality power plant. Kontronik is shown, but HET-RC, Mega and Hacker all make good brushless motors

A Wemotec Minifan 480 is used for this model

Photo shows the fan and all the parts. Note that it comes with two silver 2.5mm motor mount bolts, but most motors require 3mm x 6 bolts so these weren't used

When installing a motor adapter, it may need heated with a torch so it slips on the motor shaft easily

Check for a good installation

Add some Lok-Tite to the set screws

Install the set screws... note the spacing at the base needs to be checked so the adapter is not installed too far back or the rear of the fan will rub against the shroud when installed	Install the motor in the fan housing	Two parts not used for this installation can be disgarded NOTE: For those of us who don't check our fans on a regular basis, it is recommended that you add the small spacer ring on the rear of the motor. Over time, the motor screws can and will slowly work itself loose causing the rotor to come in contact with the inside of the shroud. This can result in the blades scraping and in some situations, breaking. Special thanks to Al Mostek for this helpful tip.
Use some 3mm hardened hex bolts to install the motor in the shroud	Install the fan rotor over the shaft adapter	Add the washer and nut

Slot the tip of the shaft so the nut can be tightened

You should have cut a decent slot in the shaft

Use a screwdriver to hold the shaft while it's tightened with a 10mm wrench

The hub can be installed or left off. It is recommended you not use the hub in high power applications above 3S Lipos

The fan assembly has been completed

It is recommended you solder plug tips on the motor, as it allows you to more readily switch between aircraft

Finish installing the plugs on the motor wires

Connect the motor to a receiver and battery to adjust balance. The cone was loosened and rotated 90 degrees at a time until minimal vibration was found while running

Fan assembly is shown balanced and ready to install

Install the fan in the fuselage, noting that it only fits and aligns up one way. If it doesn't fit, rotate it 180 degrees and try again

The rear blind nuts for the mounting bolts were installed in the jet 1/16" too far forward. Lengthen the rear mounting holes in the fan to compensate

Bolt the fan unit to the mounts using the supplied bolts

You can see the rear (right) blind nut and why the holes needed extending

Fan installation is completed

Double-thick double sided tape added to the bottom of the receiver

Install the receiver as shown

This was the best spot to place the receiver, as it allows connectivity to all channels without the use of extenders

A rear view shows the components positions... it all fits

Install an antenna rod by drilling through the firewall with a 1/8" bit

Insert a long antenna feed tube in the hole

Feed the tube back to the receiver area and trim this front tube so the nose cone ftis without binding

I wanted to try this position for the antenna as it give a full run for the wire from the rear to front. It worked well during range check in this position

Run the antenna wire to the front

The paper thust tube was discarded and a piece of clear plastic or Dura-Lar can be used to make a thrust tube

Cut the sheet as shown

Install it over the fan and mark a 1" overlap size front to back to trim

Clut slots 3/8" wide x 1/2" deep to clear the fan mount

Mark the end for trimming

Cut the sheet to shape, allowing for a 3/8" overlap over the outside of the fan

Temporarily install the tube and check for fit...adjust as necessary

Seam the tube with 1" wide strips of clear packing tape...tube is shown with tape already on the inside

Tack the outside tape to the board, sticky side up

Spray the tape with Windex so it can be "bubble free"

Place the tube over the tape and press down

Once finished check the fit in the fuselage. you will have to fold it as shown to get the tube installed from the rear

The correct fit is shown

Cut a wire exit hole for the ESC wires using a piece of aluminum tubing

Hole position is shown

Plug the ESC into motor. Use heat shrink on the leads so they don't come loose

Bend the ESC forward with the black power wire and servo wire tie-wrapped to the motor leads to hold them in place

Feed the two power wires and radio wire through top hole in thrust tube

Slide the thrust tube into place

Feed the servo wire towards receiver

Use a 3/4" wide strip of packing tape to hold the thrust tube on the fan housing

You only need to tape the top section of the thrust tube to the fan

Check your wiring

Make sure the wires do not bind and the ESC is centered

Rear view shows the centered ESC... note the wire tie at rear bend to keep wires from flying around under thrust

Install a battery connector at hte front wires... Deans Ultra Plugs were used and recommended

Apply heat shrink over the Deans Ultra plug wires

Install a battery

Cut a slot in the rear cover to accommodate wiring