I’ve decided to build the Fighter 4+1 VTOL kit. It will use a 6s power system for hobby use instead of the 12s commercial power system. The 4+1 QuadPlane design has always been my favorite performer in wind and has nice safety features built into APM like Q_VFWD_GAIN and Q_ASSIST_SPEED. No servos in the quad power chain.
My 6s power system is also chosen for lower cost for hobby use and for leveraging a lighter flying weight. By reducing the battery weight, it will shorten my flight times but still allow for a reasonable 600g load.
If we work backwards from the 10kg (22lbs) flying weight when using s 12s 16AH LiPo configuration that weighs 4kg (8.8lbs), we can reduce the battery weight by half (or more) by using a 6s pack.
Some Typical LiPo Pack Weights:
- 12s 16AH is 4kg (8.8lbs)
- 6s 16AH is 2kg (4.4lbs)
- 6s 12AH is 1.6kg (3.5lbs)
- 6s 10AH is 1.2kg (2.6lbs)
So I can reduce my flying weight from 10kg by 4kg or more. This allows for a much less expensive and less powerful quad motor system.
I have selected the Tarot 5008 340kv motor which is currently only $37/ea. at FoxTechFPV. By using their 18x5.5 MARKII Matte Carbon Fiber Propellers at $15/set and the Hobbywing XRotor 40A ESCs at $12.50/ea., you can get the entire quad power system shipped via DHL for about $255.
Full throttle on this quad power system will draw 20amps per motor and provide 3kg thrust per motor for a total of 12kg thrust on my 6kg Fighter. This allows for plenty of headroom and will keep the ESCs cool inside the motor mount boxes.
I’ll start posting building photos when my model arrives…
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The pricing seems to have changed in only 6 weeks at these stores. I don’t have an explanation for it.
AliExpress: Fighter VTOL kit is now $619 plus $183 for Standard Shipping to New York or $382 via EMS.
Banggood: Fighter VTOL kit is $599 plus $0.54 for USPS Shipping to New York or $12 via Priority Mail. The “Ocean Shipping” option appears to be gone.
That’s about a $200 difference in favor of Banggood. They are not yet in stock, but it might be worth the wait.
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My quad power system arrived from FoxTechFPV via DHL in about a week. I’m still waiting for the Fighter VTOL kit from AliExpress.
I was happy with the quality of the Tarot motors and 18" carbon t-style props. I have used the Hobbywing XRotor ESCs before and they work great! They should fit fine inside the motor mount boxes and stay reasonably cool with around a 10amp hover current.
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My forward flight power system is comprised of parts from previous projects. The AXI 4120/18 (515kv) motor will use an APC 15x8 e-prop. I also had an older Turnigy AE-100A ESC available which was a re-labeled HobbyWing ESC. It will be overkill for the 1500 watt capable power system as the Fighter will only be using partial throttle for cruising around while mapping.
