T25 Introduction:
T25 is the beta version 25KG VTOL abbreviation, it uses 4+1 power configuration, the pursuit of reliability. The V-tail layout and tail-thrust further enhance cruise efficiency.
The whole machine is composed of aluminum alloy, carbon round tube, carbon square tube, carbon sheet, wood piece and EPO foam.
Design parameters:
Wingspan 3.3 m, fuselage 1.75 m, fuselage height 0.36m(with carbon fiber tripod)
Wing area: 112 g/dm²
Wing load: 223 g/dm²
Economic speed: 22m/s(25KG takeoff weight), 20m/s(20KG takeoff weight)
Payload bay: 300×213×135mm (can carry lightweight LiDAR)
Battery compartment: 340×220×152mm (can hold 4 6S30000mah solid state batteries)
Motor and paddle
The maximum take-off weight of T25 is 25KG. Considering the influence of altitude change on pulling force and the 3.2V discharge cut-off voltage of solid state battery, the thrust-to-weight ratio of multiple rotors is planned to be greater than 2.
With reference to the same level configuration, the motor is selected in 6 series, 7 series and 8 series, the KV value selection is between 150-300, and the propeller is selected as 20-24 inches.
Finally, the motor and paddle were arranged and combined on the pull table for testing, considering the weight of the motor, the heating condition, the maximum pull force and other factors, and finally selected the rotor motor 6218 KV230 and the paddle 2075, and tested the maximum pull force of 12S on full charge 13.7Kg.
If taking off and landing at an altitude of more than 4,000 meters, you can replace the multi-rotor paddle with 21 or 22 inches.
The fixed wing thrust-to-weight ratio is expected to be 0.5, enhancing the aircraft's wind breaking ability. The fixed-wing motor can not measure the real tension in the air, temporarily choose 6225 KV205, paddle 2013, 12s full charge static maximum thrust 10KG. If the tail push is large, there will be insufficient tension or efficiency, and then the power adjustment will be made according to the data of the current size and throttle ratio in the later stage of the airline test.
Electrical part
The electric regulator took several engineering samples from the manufacturer, nominal 12S 160A. In order to increase reliability, I generally choose the nominal current is about 2 times the measured maximum current. The main factor is that the nominal tests are under ideal heat dissipation conditions, and it is difficult to achieve ideal conditions when installed on the aircraft.
Interface of the electric harmonic wing is temporarily connected by screw, affected by the aluminum alloy processing cycle, the straight pipe used in the test phase, and the planning arm is foldable.
Interface of the wing power supply and signal adopts two high-current connectors, with a single high-current connector lasting a maximum current of 40A and working for a short time to 80-100A.
Steering gear section
The 3054 model for aileron steering gear is driven in parallel by two steering gear because the rudder surface is too large
The airspeed gauge is mounted in the rudder compartment and leads the pitot tube towards the leading edge of the wing
The tail adopts metal steering gear, the working torque is 10kg.cm, and the direct drive mode is adopted. The steering gear is not installed in the tail wire.
The tail rudder surface is also relatively large, the rigidity is not enough, and the direct drive may lead to unsatisfactory conduction, which is temporarily strengthened with stickers.
Flight control section
The GPS is temporarily placed outside the cabin, using an external compass to resist interference. It was eventually installed in the cabin near the top. There is no GPS safety switch, the safety switch is independently mounted on the side of the fuselage.
PixPilot V6 Pro for flight control and T900 Pro for data transmission
This PMU has been modified to support 14S 160A current detection. However, the heat detected by resistance sampling is relatively large, and the Hall detection of 200A will be changed in the later stage.
Power supply of the steering gear is still independent UBEC to avoid interference.
Battery part
Temporarily used 4 pieces 16000mah format 15C general pressure, the weight is about 7.2KG;
The next step is to use 4 pieces of 22000mah format 25C general pressure, the weight is about 10KG;
The final plan is to use four 30000mah solid state battery 5C, weighing about 10.5KG;
For the time being, it is not planned to use a larger 36000mah solid-state battery, for a 20KG class aircraft, the battery weight accounts for more than half of the aircraft, and the load efficiency is not very high.
Summary section
The above is the electrical part of the aircraft, without batteries and loads, the empty weight of 9.5KG.
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The future of the T25 is full of uncertainties and needs to be created together with users. Welcome to vote, your participation can help us get close to the real needs, improve the user experience, and make simple, beautiful and universal products.
In what scenarios do you think T25 is useful? Multiple choice
1. Equipped with 3KG LiDAR mapping
2. Teaching and training as VTOL four machines
3. Carry 3-5kg as a prototype for logistics transportation
4. As a research platform for large load and long voyage
5. Other
How many S batteries do you want the T25 to use for easy installation and charging? single-choice
12S lithium polymer battery
14S lithium polymer battery
18S lithium polymer battery
24S lithium polymer battery
What length do you want the T25 to be after packing? single-choice
1.35m (can be placed in the back of the car)
1.5m (can be placed in the rear of the SUV with one seat down)
> 1.5m (large models, length is not a major consideration)
How long do you expect the T25 to carry 3KG? single-choice
About 150KM
About 200KM
More than 250KM
How long do you expect the T25 to carry 5KG? single-choice
About 100KM
About 150KM
About 200KM
More than 250KM
What capacity batteries do you usually use? Multiple choice
6S 16000mah
6S 22000mah
6S 25000mah
6S 30000mah
12S 16000mah
12S 22000mah
12S 25000mah
12S 30000mah
Other capacity