JF 17 Thunder Block 1 90 mm Electric Ducted Fan Model Aircraft by Khizer Bin Younos
Ever since I saw JF 17 Thunder with the Pakistani Flag at Farnborough air show I just fell in love with this jet because it’s the first ever Pakistani Jet fighter which has amazed the whole world with its simplicity and performance. Growing up as a child I had a deep affection and liking for PAF and now when a I saw our own world class Fighter Jet standing proudly among the 4th + Generation fighters, it was time for me to get a rc model of this fantastic jet. I already have a few static models.
Looking around and searching the web, I found a suitable airframe 90mm Ducted Fan from The Wing Makers ( unfortunately this model has been discontinued now).
This JF17 Thunder airframe is a 90 mm EDF (electric ducted fan) designed to run on a 6S (22.4V) setup with 9 servos.
The airframe is made up of EPO (Expanded Poly Olefin) type foam. This is a closed cell type foam and formulation varies from manufacturer to manufacturer. Normally it is a rough foam not as smooth and shiny like EPS or EPP. However the EPO developed by Wing Maker is silky smooth and has a waxy appearance. This type is used both on JF17 and J10. It’s extremely tough material and very difficult to paint due to its unique waxy texture.
The airframe has 2 aerodynamically engineered inlets providing 125 % FSA which eliminates the need for any cheater holes. This quite unusual for an EDF model as 95% of the EDF’s on the market use some sort of cheater holes.
The airframe has wings blended into the fuselage with long LE extensions which enable the plane to fly at slow speeds without compromising stability.
The first thing I did was to coat all the stress points with Foam Armour which even strengthens foam further to near fiberglass strength with minimal weight increase. I have done over 50 flights and still the airframe is good as new with no signs of any wear & tear. My model is based on Block 1 version , Serial number 10-123, Black Spiders Squadron which was piloted by Wing Commander Zeeshan Baghair at the Paris Airshow.
I have added panel lines and some markings myself to give it more scale appearance.
Since I fly from a grassy runway, I wanted to have a power unit with enough static thrust to take off easily from grass and also wanted to have a good flight time because most EDF’s on the market only fly for 3 minutes or so before the battery runs out.
After doing some research I opted for a WemoTec 90 mm Midi Pro 6 blade with a HET Brushless motor. This system provides 2400 g (~24 N) of static thrust with 6S and flight times of 6 to 6 ½ minutes with some throttle management. My setup uses a thrust tube to further enhance the performance. Based on the peak current draw I used a Turnigy 80A esc.
I used my trusty JR XG11 with RG831 X-Bus receiver to control the 8 servos + throttle to control the JF17. I used Spektrum A3030 digital servos throughout the model on control surfaces and MG90D on 3 Mechanical retract units.
The JF17 can take off from grassy runways with ease even with the tiny 1.5 inch wheels. Aerobatic performance is very good for all regular jet manoeuvres like figure of 8’s, loops, rolls and wing overs. Rolls are very axial and smooth. Due to the design of JF 17 the fuselage is also a lifting body blended with fuselage just like the F16. The plane has not got enough side area and is not affected by cross winds at the same time knife edge flight is quite challenging but that’s okay fighter jets are not designed for knife edge anyway. The ailerons can mixed as flaperons to slow down during landings but I did not feel to use flaperons as JF17 has excellent slow speed characteristics. I have pulled very hard turns on this model and it does not buffet at all even when you pull it from a full throttle dive.
Top speed is very good however my setup is designed for more flight time and more static thrust rather than speed. I believe the model has potential to gain another 30-40 km by changing to a smaller dia. Thrust tube and higher kv motor at the expense of flight time but for the time being I am very happy with my setup.
My timer is set at 6 minutes 30 seconds with a 4500 mAh Battery. I have found this to be the best for right balance and flight time.
Further upgrades planned:
Block 2 –New Tail with ECM Pod containing JR Variometer and Altitude Sensor , Wemotec 9 blade turbine
Block 3 – Wemotec upgrade to 8S setup with HV ESC, JR pitot tube speed sensor, Afterburner
Block 4 – Thrust vectoring nozzle
Video link of the Maiden Flight:
If you have any comments or want to get more information you can write in comments section below.