Apache project 1/18 scale

General characteristics

Data from http://en.wikipedia.org/wiki/AH-64_Apache

• Crew: 2: pilot, CPG (co-pilot/gunner)
• Length: 58.17 ft (17.73 m) (with both rotors turning)
• Rotor diameter: 48 ft 0 in (14.63 m)
• Height: 12.7 ft (3.87 m)
• Disc area: 1,809.5 ft² (168.11 m²)
• Empty weight: 11,387 lb (5,165 kg)
• Loaded weight: 18,000 lb (8,000 kg)
• Max takeoff weight: 21,000 lb (9,500 kg)
• Powerplant: 2× General Electric T700-GE-701 and later upgraded to T700-GE-701C & T700-GE-701D (1990-today) turboshafts, -701: 1,690 shp, -701C: 1,890 shp -701D 2,000 shp (-701: 1,260 kW, -701C: 1,490 kW) each
• Fuselage length: 49 ft 5 in (15.06 m)
• Rotor systems: 4 blade main rotor, 4 blade tail rotor in non-orthogonal alignment^[39]

Performance

• Never exceed speed: 197 knots (227 mph, 365 km/h)
• Maximum speed: 158 knots (182 mph, 293 km/h)
• Cruise speed: 143 knots (165 mph, 265 km/h)
• Combat radius: 260 nm (300 mi, 480 km)
• Ferry range: 1,024 nm (1,180 mi, 1,900 km)
• Service ceiling 21,000 ft (6,400 m)
• Rate of climb: 2,500 ft/min (12.7 m/s)
• Disc loading: 9.80 lb/ft² (47.90 kg/m²)
• Power/mass: 0.18 hp/lb (310 W/kg)

Armament

• Guns: 1× M230 30x113 mm (1.18x4.45 in) cannon, 1,200 rounds
• Rockets: Hydra 70 FFAR rockets
• Missiles: combination of AGM-114 Hellfire, AIM-92 Stinger, AIM-9 Sidewinde

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I couldn't afford the 1/7 scale, so I looked around and found this on Youtube: a 1/18 scale model.
I liked what I saw so I bought the Apache 1/18 scale from ebay (BBI 21st Century Toys Elite Force AH-64 Apache 1/18) for $65. This project took most of my spare time and I started it the wrong way. I ended up swapping three different mechanical parts in and out to get it right. I will try to detail them as much as I can.







BBI 21st Century Toys Elite Force AH-64 Apache 1/18


First off, I was frustrated with the available 4 blade rotor head. I went ahead and bought an old lathe to make my own rotor head. I've never operated a lathe before, but I can tell you it's not that hard anyway.



With the old lathe and mill combination machine in hand, I started to make my own parts. This is the 4-blade head I made. It has 5mm shaft, but later on I transferred into 8mm for the Trex500.


Complete assembly inside look


Detail of the mechanic


Detail of 4-blade rotor head and the anti-vibration on top
Note that the rotor head fits onto the Trex500 8mm shaft and the grids are Trex450


Torque tube tail drive. Custom made for angle.


Closeup of the angle


Detail of the 4 tail blades. The tail blade is made from the CX2 blades


After several weeks' work, here is the completed model ready for its first test!















4 blades tail














From top














Here is the flight test on July 22, 2008, a month after the cobra.
My back yard is small, so the test was just vertical up-and-down flight. I haven't tried to land on a small landing spot like the 5 gallon bucket nearby yet - I actually may not be able to land on small areas like the cobra can. I found it harder to fly compared to the cobra - it must be heavier.


Will have more video when I test it at the park.
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First test at the park. Unfortunately, I don't have the right battery (not enough discharge current for the 500), so I lost power to keep it up. Will try again when I have the right battery.
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Second test at the park on Sunday Oct. 26, 2008