Build Articles
HET-RC - F-16 Falcon EDF
By Carl Tulanko
February 15, 2007 - 11:53:25 PM

01 - The F-16 as it arrives well packed from Markos at Warbirds-RC	02 - The model is double boxed and all parts are wrapped for protection	03 - The HET-RC F-16 Falcon ARF Minifan 480 Jet out of the box
04 - The major components of the model. It is very similar to the HET-RC FA-18 in construction and covering	05 - Front view of cockpit area. The glass work is very well done	06 - Rear view showing pre-installed Fiberglass Intake and formers
07 - Construction: Sand the wing saddle on the fuselage for good glue purchase	08 - Five Minute Epoxy is applied in the wing spar hole using a cut down mixing stick to fit the slot	09 - Next, insert a wing spar until it bottoms out in the slot
10 - Spar shown installed	11 - Clean up excess epoxy with some paper towels and denatured alcohol	12 - Spar installation shown completed
13 - There is a left and right wing. The side with less curve is the bottom, so mark them "left" and "right"	14 - The wing is placed over the spar and adjusted so it is centered in the rear and the front of the fuselage. This will adjust the spar to the correct position. Carefully remove the wing and let the spar glue set	15 - The wing shown installed and flush in the front of the fuselage shows a gap at the rear. This will be filled with Epoxy when the wing is mounted
16 - A 1/8" drill bit is used to make some holes in the fuselage. This will allow the epoxy to create "rivots" inside the wing saddle for a stronger joint. Lightly sand after drilling to remove burrs	17 - Fifteen minute Epoxy is applied to the wing root	18 - Fifteen minute Epoxy is applied to the wing root.
19 - The wing is set in place. If you fiberglassed your wing, masking tape is used to keep excess epoxy from adhering to the finished surface. Make sure the wing is centered and the bottom of the wing is flush with the root molding of the fuselage. Keeping the bottom of the wing flush with the bottom of the fuselage will insure correct incidence without any twist for the wing position.	20 - Denatured alcohol is used to remove the excess epoxy	21 - The front of the wing is centered and held in place with masking tape. The rear is centered and held in place with a clamp and left to set
22 - The other wing saddle is sanded for better glue purchase. A small piece of 60 grit sandpaper makes quick work of it, but be careful not to oversand	23 - Epoxy is applied to the spar slot with a cut back mixing stick	24 - Epoxy is applied to the spar and the wing spar is installed until it bottoms out in the slot

25 - Excess glue is cleaned up with denatured alcohol and a paper towel	26 - Spar is installed	27 - Wing is placed in position and centered in the front and back to correctly position the spar, then it is carefully removed before the epoxy sets, then the spar is drilled for rivot holes
28 - Epoxy is applied to the wing root	29 - Next epoxy is applied to the fuselage wing saddle and spar	30 - The wing is installed on the saddle and centered. Excess epoxy is removed with denatured alcohol and a paper towel. Then tape is used to keep the front of the wing centered and the bottom of the wing flush to the fuselage root while a clamp keeps the rear centered until the epoxy sets
31 - Epoxy is applied to the joint as a fillet. A toothpick is used to apply it and the tape was place on the surfaces to catch the overflow	32 - The excess epoxy is wiped off and overflow lands on the tape	33 - The tape is removed, revealing a clean joint. Repeat and do the same on the other side of the model
34 - Wings are shown installed on the fuselage	35 - Front view of wing installation shows wings with a couple of degrees on anhedral. This was due to the design of the fuselage	36 - The vertical stabilizer area of the fuselage is taped off so sandpaper does not mar the finish
37 - Sand the sides of the saddle with 80-100 grit sandpaper. Be very careful as to not oversand as you could cut through the glass	38 - Side view shows edges sanded and ready for epoxy	39 - The top outside edges were sanded so any excess glue would adhere well and form an internal fillet. While it is not necessary, the entire top of the saddle area was sanded in the pic
40 - Stab area sanded. Be careful to not oversand...if you do, simply apply a coat of epoxy on the inside area of the fuselage to strengthen	41 - Marks were made in order to cut two 1 1/2" long slots in the vertical stab area that are used for both cooling and the receiver antenna	42 - A Dremel with a stone cutting wheel was used to open the slots
43 - A hobby knife is used to clean the corners and remove large burrs	44 - Some 400 grit sandpaper is used to smooth the edges inside and out	45 - The two slots are shown finished. This completes the Vertical Stab pre-assembly
46 - The wood pieces that are needed for Taileron assembly. Make sure you make two opposite/mirrored trays, one for the left and one for the right. The side plates are labeled S for Short and L for Long with the long side facing the front of the fuselage when installed	47 - The two ends of both servo trays were lightly beveled with 400 grit so they could fit in the slots of the side plates	48 - Use a ruler to mark center on the servo tray

49 - Mark both trays with a center line for your servos

50 - The HS65 servos are a perfect fit and were inserted in their tray to mark for drilling. The was some play in the tray, so the servo was pushed flush against the left side, then holes were drawn on both ends. It was then pushed flush to the right side and marks were made again

51 - You can see the two marks made at each end. Draw a line between them for a perfect center

52 - Use a punch to mark where the holes need to be made

53 - Use thin CA to coat each mounting hole area on both sides of the tray. This will prevent cracking and splintering when drilled

54 - The tray is lightly sanded to smooth out the CA glue area

55 - You need a hobby drill smaller than the standard US 1/16" because the servo mounting screws are so small, so I found that a medium hobby push pin would work. Use a hammer and carefully drive it through the tray like a nail, being careful to keep it straight. Remove the pin and insert it in the back side of the tray to open the hole a bit	56 - Photo shows the pin driven through the plate	57 - Servo mounting screws are installed to "cut" threads in the wood
58 - Temporarily install the servo...the screws should match up with the holes and the servo should be centered in the tray	59 - Insert a tray into a side plate. Note that the thin side of the tray faces upward toward the angled side of the plate. Do not push in all the way	60 - Install the other end of a tray into a plate, with the angled side of the plate facing the thin side of the tray. Be sure to use a short plate on one end and a long plate on the other end

61 - Mix some 5 minute epoxy and use a toothpick to roll it into the joint at both ends	62 - Squeeze the plates in place and flush	63 - Remove the excess epoxy that could prevent the servos from sitting flush
64 - Removing the eopxy leaves a very fine fillet	65 - Square up the tray before the epoxy sets	66 - Build the other tray and make sure you make two opposite "mirrored" trays
67 - Once both trays are completed, add a fillet of epoxy to the rear for added strength	68 - Remove the excess epoxy so a nice fillet is made	69 - Servo Tray construction completed and showing fillets at rear side

70 - From the top of the fuselage- The stab block and servo tray are shown near the positions where they will be installed in the fuselage. Note that the block tapers rearward and that the tray has the "Shorter" side to the rear with the thin part of the tray pointing to the top side of the fuselage	71 - The position for the Horizontal Stab rods is 62mm from the rear	72 - When first installed inside the fuselage, the blocks were set too far back and not centered over the mark
73 - A piece of 1/32" ply was cut as a shim to make the block thicker	74 - The shim is epoxied to the bottom of the block	75 - With the addition of the shim, the block is inserted and the photo shows where it now would sit inside the fuselage
76 - The second block shim is added using 5 minute epoxy	77 - Lightly sand the edges to even out the shim with the block sides	78 - A Warning...the manufacturing process left some strands of fiberglass that were sharp as needles and located where the pencil is pointing. If you have these, carefully break them off inside so you do not get cut

79 - A mark is made on the outside of the fuselage at 62mm

80 - A second horizontal mark is made at the center of the fuselage

81 - A 1/8" Drill is used to open the holes at the crosshairs. You may want to use a small bit to make a starter hole first

82 - Masking tape is used to wrap around the block so it can be removed easily later

83 - The block is temporarily installed in the fuselage

84 - Keeping the drill square, make a small mark on the ply inside but do not drill through

85 - The drill mark is shown centered in the block	86 - The other block is installed and marked the same way. Use the masking tape tab to easily remove the block once it is marked	87 - A drill press is used to drill through the block and keep the hole square
88 - A Hinge drilling jig can also be used to drill a square hole	89 - If you do not have a drill press or hinge jig, the the hole can be carefully drilled by hand. Do a little at a time making sure the bit stays square both horizontally and vertically	90 - Trial fit the Elevon Rod and use the drill to open the hole if necessary so the rod moves in and with little effort

91 - Install the block in the fuselage with the angled side toward the top. Do not glue the block in place yet	92 - Make sure the hole is aligned and centered on the markers	93 - Temorarily install a Elevon rod to check the angle
94 - Rod shown in correct position, perpendicular to the fuselage where it exits. Note that the fuselage is molded to include a downward angle on the rod when compared to the wing...this is normal	95 - Two 1/8" wheel collars are required to retain the horizontal stabs. You may have to purchase a set as they were not in the kit	96 - Apply some blue Loktite on the setscrew for the wheel collar
97 - Install the setscrew in the wheel collar	98 - The Horizontal Stabs may need to be ironed to remove wrinkles	99 - The wheel collar is shown installed where it is used to mount the stab

100 - The wheel collar deforms the top of the monokote	101 - the first 1/2" of the Horizontal Stab rod is roughed up with 60 grit	102 - Install the rod in the horizontal stab and lock it in place with the wheel collar. Make sure that the rod extends past the collar and butts against the left wall as shown. Also, note that the side of the rod that was sanded is shown to the right and will be glued into the fuselage block
103 - Apply epoxy inside the hole with a toothpick	104 - Apply epoxy to the top and bottom of the block	105 - Install the block in the fuselage
106 - Install the Horizontal stab into the inner block hole until the root butts against the side of the fuselage. This will keep the block aligned inside. Put your finger inside the fuselage and make sure the block is settled in its location. Hold the stab tight in place with masking tape	107 - Check stab position from the rear to make sure the angle is aligned with the fuselage trailing tip	108 - Epoxy is applied with a toothpick to the second block hole
109 - Epoxy is applied to the top and bottom of the block, then it is installed	110 - Horizontal Stab is installed through the hole and into the block	111 - Masking tape is used to hold the stab flush to the fuselage side. Check your rear angle as you did with the first stab and make sure it aligns with the fuselage trailing edge
112 - Horizontal Stabs shown installed and in place	113 - The stabs have a slight downward angle from the rear, which should be even on both sides	114 - Use a hex wrench to loosen the retaining wheel collar

115 - Remove the stab and wing collar from the fuselage	116 - Horizontal Stab rod installation completed	117 - The fuselage halves were assembled using what appears to be Aeropoxy, as shown by the arrow. This will prevent the servo trays from seating all the way into the fuselage area. It cannot be easily reached to be sanded
118 - Masking tape is applied to the side of the fuselage area and marked for servo cutout	119 - A Dremel with a stone wheel is used to cut out the opening	120 - Opening is shown rough cut. It was very difficult to cut through the Aeropoxy ridge inside. I used a pair of 90 degree long nosed pliers to break through
121 - The opening is filed until the servo can pass through easily	122 - The tape is removed from the opening	123 - The other side is cut with a dremel and corners are cut with a hobby knife
124 - The opening is filed until the servo can pass through easily	125 - A notch is cut in the area where the Aeropoxy seam hits so the tray will sit flush with the outer wall	126 - A slight bevel was added to the tray for easier insertion of the servo
127 - Epoxy is applied to all edges of the tray, both top and bottom	128 - The tray is inserted into the fuselage and placed in position	129 - The tray is shown set in place; make sure it is centered over the cutout you made for the servo. Add fillets of epoxy as necessary
130 - The second tray is prepared for installation	131 - The second tray is installed	132 - Trial fit a servo into the tray
133 - Servo set in place...do not screw in place yet	134 - Push the servo out of its tray from inside and using your radio or a servo tester, center the servo, then temporarily install the horn	135 - Install horn so it is perpendicular to the fuselage
136 - Remove the upper portion of the horn and sand to round it out	137 - A 1/16" drill bit is used to drill the hole that is closest to center	138 - The horn is cut at the second hole and rounded as shown

139 - Install the sevo horn pointed down and centered, then use the servo horn retaining screw to premanently fasten the horn

140 - Perform the same steps to the other servo horn, cutting to length and shaping. Install the horn pointing downward

141 - Install the servo horn retaining screw

142 - The servo is mounted in position using the supplied mounting screws

143 - Slide one of the two washers in the kit over the Stab shaft. This will act like a bearing for the stab and prevent rubbing on the sides of the fuselage

144 - Install the stab and retaining wheel collar

145 - Holding the stab tight against the fuselage, tighten the wheel collar

146 - Install the other washer, stab and wheel collar, then tighten