Greg Covey

The Great Planes ElectriFly [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYXN6&P=ML]F-20 Tigershark[/link] is a sport-scale EDF ARF made from lightweight and durable Aerocell foam construction. It includes a HyperFlow ducted fan unit with a powerful Ammo [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLWX8&P=7]20-45-3790[/link] inrunner brushless motor. Also included are two AIM-9 Sidewinder missiles and a display stand that lets your F-20 EDF look as great on the ground as it does in the air!

The F-20 Tigershark EDf ARF can reach speeds of 85mph using the recommended power system. The pre-assembled cockpit includes a pilot, dashboard controls, and is held in place with powerful magnets. There are few parts to put together so the assembly is fast and easy.

Specifications:[ul][*] Wingspan: 22.5 in (570mm)[*] Wing Area: 162 sq in. (10.4 sq dm)[*] Weight: 26.8 oz (760 g)[*] Wing Loading: 23.8 oz/sq ft (73g/sq.dm.)[*] Length: 37 in (940mm)[*] Center of Gravity: 3.75" (95mm) back from the leading edge of the wing measured at the fuselage[/ul]
Features:[ul][*] Made from lightweight and durable Aerocell foam[*] Two-piece wing with carbon wing spars and pre-hinged ailerons[*] Removable foam wing tip missiles (for display only)[*] Clear canopy with painted pilot bust and instrument panel decals, magnetically secured canopy hatch is removable for battery access[*] Foam Display Stand with easy tab and slot assembly (NOT AeroCell foam)[*] Ammo brushless motor (24-45-3790) with HyperFlow ducted fan unit (Included)[/ul]

Greg Covey

The fuselage and parts were very well secured in the box using plastic bags, custom compartments, and tape. There were no loose parts to get damaged. Two manuals were included, one for the HyperFlow fan assembly and the other for the model assembly. One of the decal sheets provided was for scale markings and the other for promotional branding.

The control surfaces were pre-assembled including the horns and quick links. All the control horns were additionally protected by custom foam pockets that could easily be removed after shipping.

I was surprised to see servo extensions and a motor included in the kit. This was a nice added touch by Great Planes!

Greg Covey

A closer look at the fuselage revealed several design details. The AeroCell foam made the fuselage very light but not delicate. The surface did not appear prone to dents or rash. The detailed canopy was magnetically secured for easy access to the F-20's battery compartment. Likewise, the aft hatch that secures the HyperFlow DF could be easily removed by sliding it back and then lifting out.

Strings were pre-placed inside the fuselage to allow easy routing of the servo control wire extensions.

The air intake ducts and exhaust area were optimized to provide maximum speed and efficiency to the F-20.

djsqueeze

My Feedback: (7)

What?? No landing gear?
I like it, but are you going to make any mods. to it?

Greg Covey

Landing gear on these smaller hand-toss foamies just make it look less scale when flying. They are easy to launch and belly land in the grass. Check out the similar design by Great Planes of the L-39 Albatros EDF Jet [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=1098]here[/link].

Greg Covey

I'm using the following components to complete my F-20 Tigershark.
[ul][*] Great Planes Silver Series [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKSY6&P=7]45A[/link] Brushless ESC[*] Great Planes ElectriFly LiPo Pack [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXWRA7&P=ML]4S 14.8V 2200mAh 25C[/link][*] Futaba [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXTHL6&P=ML]R617FS[/link] 2.4GHz FASST 7-Channel Receiver[*] Three Futaba [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNCV6&P=ML]S3114[/link] Micro High-Torque Servos
[/ul]

Greg Covey

The Tigershark assembly begins with gluing a carbon rod into a channel on the bottom side, followed by the wing halves and a foam filler piece. Since Aerocell foam loves CA and kicker, this is a quick assembly.

Likewise, the horizontal tail piece is glued to the bottom of the fuselage into a custom channel. The piece is held forward in the channel to allow for proper operation of the pre-assembled elevator joiner.

Before you know it, the model looks like an F-20 Tigershark!

serge1

My Feedback: (1)

Ya landing gear on those little jet are really not needed. I fly my 6S jets with no landing gear for maximum scale appearance and speed.

Greg Covey

Assembling the HyperFlow fan unit was fairly straightforward. The unit allows for several size motors so I needed to trim away the alignment guides for my AMMO 24mm motor. This job was made much easier with a Dremel tool sanding barrel.

The spinner is left off for this model and the stator extension is pressed into place onto the back of the ducted fan housing. The extension is secured with a few drops of medium CA. Locktite thread locker was applied to all screws on this part of the assembly.

The instructions recommend testing the fan unit prior to gluing it into the fuselage. I was disappointed when the pre-installed bullet connectors on the AMMO motor did not fit properly on the Silver Series 45A ESC connectors. They were simply too loose. Fortunately, I had many bullets on hand from previous projects and found a mating set to replace the ones on the ESC.

The rotor had a slight area of rubbing onto the fan unit but I knew that a few seconds of running this soft plastic would correct the issue. When I ran the system up on my bench, I was happy with the excellent amount of air getting pushed through the fan. This power system should work very nicely with the F-20 Tigershark.

Greg Covey

The tested ducted fan unit is secured in the fuselage using glue or servo tape. I used a small amount of 5-minute epoxy.

When using the Silver Series 45A ESC, the wires are too short to reach from the motor to the cockpit. Great Planes has provided extensions for the three motor wires that also act as size converters for the different bullet connectors on the ESC and AMMO motor. Three pieces of shrink tubing are also supplied to cover the connectors at the joint.

Since I didn't see my supplied extensions until later in the assembly, I extended my own ESC battery wires by 4" so that I could have reasonable access to plugging in the battery pack.

Note that I color-coded my black wires on the ESC with paint so that I did not need to re-test the power system for proper rotor rotation. I also added two small cable ties to secure the motor and ESC wires from vibrating during flight.

The intake ducting looked like it was designed very well and should be quite efficient. Even the combiner area of the two intake ducts formed into a round foam rod that actually plugged into the rotor center. Since the foam is soft, the first second or so of the motor running will seat the rotor properly if there was any rubbing. I cut about 1/4" of the foam rod off for a proper fit without excessive rubbing on the rotor.

Greg Covey

I made a mistake in the assembly by not finding the supplied motor lead extensions. They are made with larger connectors on one end for the Silver Series 45A ESC and smaller connectors on the other end for the AMMO motor. They are supplied in the bag with the servo lead extensions and eliminate the need for any soldering. It looks like Great Planes has thought of everything.

The Futaba S3114 servos mounted in the custom pockets using a small amount of medium CA. The servo leads are tied to the strings and then routed back towards the DF unit. The leads are then connected to the supplied extension and Y-harness before their final routing through the fuselage to the battery bay.

I used a small amount of medium CA to attach the plastic extension connector to the foam side and neatly routed the wires. Although heat shrink tubing is supplied to secure the servo leads in the extensions, I used some green 3M masking tape. Before fitting the motor hatch to the fuselage, I removed the 72MHz antenna tube since it was not needed. The hatch has plywood hooks and strong magnets to secure it in place.

barnesjonr

My Feedback: (1)

I have been following your thread with interest Greg ... and when you posted that you had to extend the leads, i was a bit surprised, as Great Planes and ElectrFly typically do include the necessary extensions. I am glad to see they still do and am sorrow you missed them.

I am really looking forward to seeing you get this little EDF in the air!

Greg Covey

Hi Jon,

Yeah, I should have looked closer at all the parts. Fortunately, I can solder so my concern was for others that may not want to do it.

The Tigershark design looks quite efficient in the ducting design. I hope to test fly it on Memorial weekend so stay tuned and feel free to comment.

Regards.

barnesjonr

My Feedback: (1)

I will be building one myself soon.

I am currently flying another recent release from the same folks,  the ElectriFly Evader. It uses the exact same power system as the F20. It is quite slippery and really hauls the mail!

Greg Covey

The control rods were any easy install since they were pre-bent and cut to length. The Z-bend went in the center servo hole and the straight end into the pre-installed quick link. I added some Locktite to keep the screws secure.

The aileron control surfaces were aligned to meet the fuselage flat bottom and the elevator to center in the stabilizer. The main wing appears to be flat on the bottom and the stabilizers are symmetrical airfoils. Once the rods are installed, the servos covers simply press into place after peeling the paper off the pre-applied double-sided tape.

The vertical stab presses into place after applying some medium CA to the base. The tail cone can either be taped in place or held by a few drops of CA. I used some CA for a cleaner look.

vwalton

Regarding the aileron servos: you have strings running from the aileron bays back to the EDF bay? On mine I have strings running from the aileron bays forward to the radio bay - and a third string running forward from the EDF bay to the radio bay (for the elevator servo). And for the life of me I couldn't figure out how they expected me to get the y-harness on those servos!

Greg Covey

If you look closely at the center photo in post #10, you'll see the two aileron strings are looped into the back EDF area before going up front. Perhaps your model was installed wrong at the factory. I don't think the strings can pull through due to the fuselage foam blocking the loopback section.

Good luck on your Tigershark and keep us posted!

Greg Covey

The CG lines were marked at the recommended setting of 3-3/4" back from the leading edge (LE) of the wing at the fuselage. Don't use the air intake duct as it is 1/4" forward.

The battery needed to go as far forward as possible to achieve the CG. This required that the hook and loop material did not go forward of the battery half point for it to fit in the nose.

It was time to add some decals...

Ductedfann

My Feedback: (2)

Nice little plane, nice post Greg.

Morris

Greg Covey

Thanks, Morris. I hope you have some of those nice Dual Rotor Upgrade Kits ([link=http://www.ductedfans.com/SF_airways_45.html]WE504ex2[/link]) in stock because my new AMP'D column will be out this weekend and it's all about Business Class EDF.

Regards.

Greg Covey

My F-20 Tigershark was Ready-To-Fly at 27.1oz (1.7lbs) including the 8.7oz LiPo pack. I measured 550 watts at 37 amps after 10 seconds of full throttle. This provides an awesome 324w/lb so this little foamie should really go!

I know the decals are not exactly scale but I got carried away.

I mounted the F-20 in my trailer for some Memorial weekend fun. I'll report back next week with some video and flying photos.

barnesjonr

My Feedback: (1)

MIne goes up for it's maiden today ...

Greg Covey

Jon,

I noticed that you used the non-scale flag on the right side. The flag must always have the stripes toward the tail of a plane. The decal set should have provided this because many of the other decals were properly reversed.

Good luck on your maiden!

barnesjonr

My Feedback: (1)

Whoops, thanks Greg! I better fix that before Iget her in the air or snap any more photos!

barnesjonr

My Feedback: (1)

Maiden and one other successive flight went off without a hitch. The F20 is an honest flyer but like other F5/F20 variants Ihave flown, the stubby wings create just a wee bit of a need to keep your eyes on it without a untimely blink, lest your brain fool you as to it's orientation. Itook it easy on the new battery and didn't push it too hard. Moves nicely on the stock power system, with an easy hand launch and landing too.

Hope you don't mind me posting this in the thread you started Greg?