Fokker D7 by Foamworks
and available through Electro Aero Modeling USA (http://www.eam.net/)

25 Sep 17 - More information on the gearbox added

Fokker D7 - aft port quarter
 
N of launches/Time 11 1 hour 3 mins

includes flights of all configurations

Wingspan 31 " 0.79 m
Wing Area 298 in 19.2 dm
Flying Weight 9 oz* 262 g* 8 oz* 248 g 8.9 oz. 253 g 8.9 oz. 253 g
Wing Loading 4.5 oz/ft 13.6 g/dm 4.2 oz/ft 12.9 g/dm 4.3 oz/ft 13.2 g/dm 4.3 oz/ft 13.2 g/dm
Wing Cube Loading 3.1 = Glider 2.9 = Glider 3.0 = Glider 3.0 = Glider
Motor Multiplex 150 Feigao 12mm thin Brushless 5800kv Feigao 12mm thin Brushless 4100kv
Gearbox Twin ballrace 9.7:1, supplied with motor Twin ballrace 9.7:1 GWS IPS-DX2BB 'A' Twin ballrace 82T/14T 5.85:1
Propeller GWS 10" x 4.7" (slow-fly) GWS 8" x 4.3" (slow-fly) GWS 10" x 4.7" (slow-fly)
Batteries 7 cells - Sanyo 250AAE NiCd , 7 600mAh AAA NiMH or 7 Sanyo 110AE NiCd*  2S2P Kokam 340mAh SHC cells (20C rating) or
2S1P Kokam 740mAh SHC cells (20C rated) or
2S1P Kokam 910mAh SHC cells (20C rated)
Speed Controller Ripmax P-Xtra-05 Air - 5 to 8 cells - 5A - BEC Robotbirds Budget micro Brushless  10A- 2-3 LiPo - 10A - BEC - Brake
Receiver GWS Naro R-6N/H - 6ch - sub-micro - 35MHz
Servos Elevator - Hitec HS-50
Rudder - Hitec HS-50
Static motor parameters 

7 Sanyo 600mAh AAA NiMH gives 3200 RPM @ 7.6V drawing 2.4A, giving 18W, approx. 31W/lb.

2950 RPM @ 7.1V drawing 2.2A, giving 15.6W, approx. 28W/lb. 2S Kokam 710mAh SHC cells gave 6300 RPM @ 7.27V drawing 4.4A, giving 32W approx. 57W/lb. 2S Kokam 710mAh SHC cells gave 3825 RPM @ 7.4V drawing 3.4A, giving 25W approx. 45W/lb.
Flight Performance Not yet flown I flew very well with the control being very nicely balanced.  However, full throttle only gave a meagre climb and was need at all times. Flies very well with a good rate of climb and will loop from level flight with ease. Flies very well with a good rate of climb and will loop from level flight with ease.  Probably not quite as good as the 5800 rpm/v motor, but I'm still optimising the propeller choice.

25 Sep 17 - I was asked for information on the specific gearbox used so have updated the table.

21 Apr 07 - Repairs complete

10 Apr 07 - The Fokker came a cropper today when I landed in long grass.  It ripped off the wings on one side, but wont take too long to repair.  Whilst it wasn't a problem in flight, I will be sorting out the slight warp in the wing while I'm at it.

7 Apr 07 - Feigao 4100 RPM/v motor fitted to the DVII this morning and connectors converted to 3.5mm gold as I am adopting this as a standard for almost all application.  The only exception will be in application that pull more than 40A where 4mm gold connectors will continue to be used.

23 Mar 07 - Having flown the DVII again I am going to fit the slower 4100 rpm/v volt motor fitted to a GWS 5.85:1 gearbox in place of the current 5800 rpm/v motor and 9.7:1 gearbox.  The slower motor should allow the fitting of a 10" or 11" propeller which will be better suited to this style of model.

14 Mar 07 - I can't believe it took so long for me to get around to test flying the DVII with it's brushless motor.  Anyway, I managed to fly it this afternoon and it is much better.  I think I'll swap the motor for the 4100Kv version (and a lower gear ratio) to allow a 10" or 11" propeller to be used.

28 Dec 05 - I finally managed to get clam enough conditions, on 11 Dec 05, when I could go down to the field and test fly the Fokker DVII.  It flew really well with the control being really well balanced and could be flown by a relative novice - a delight to fly.  However, it was lacking power and needed full throttle all the time to get a meagre climb rate.  As the original Multiplex motor was running at it's limit I had to change motors.  I have therefore got a Feigao 12mm brushless motor and fitted it to the IPS gearbox as a direct replacement for the original brushed motor.  This requires only undoing 2 screws and swapping the pinion between the motors.  I tried it with the original GWS 10" x 4.7" (slow-fly) propeller first, but it drew over 8A, which is above the 6A maximum for the motor.  Swapping to the GWS 8" x 4.3" (slow-fly) propeller pulled 4.3A, giving me twice as much power I had before- time for another test flight.

5 Jan 05 - Finally got around to digging the D7 out from the back of the garage and modifying it to take the 2 x 2-cell Kokam 340SHC Li-Po packs. Despite the frame required to hold the batteries nearer the nose the model is lighter, but the power is down due to the lower voltage of the Li-Po packs. We'll have to see what effect this has on performance. In 2P format The 340SHC Li-Po packs can actually take 13.6A although I would not run them above 10A (5A each) in the parallel configuration. The motor is only capable of withstanding about 2A continuous, so I'd need to change the motor if I were to want more power.

3 May 02 - Model is now ready to fly, and is lighter than I thought it would be with all the paint. Despite a few minor problems, it went together extremely well. I decided to omit the machine guns as they are hardly visible anyway. Hopefully I'll get to fly it in the next few days.

20 Feb 02 - I have done the initial stages of construction and have a completed upper wing and fuselage which has the lower wing attached, which is now ready for painting. The radio gear is also installed in the fuselage. The work required, post painting, is the installation of the upper wing, it's rigging and the undercarriage.

29 Dec 01 - New indoor scale kit just arrived from the USA for use with the GWS "stick" motors.

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