CMPro Leo-V2 - 1746mm   December-2013

The horizontal stabiliser has two carbon tubes joining the halves through the fuselage. I glued the front tube in place to make the whole stabiliser far more sturdy when ready to fly.

The wheels are 3.5", low bounce with brushed aluminium hubs.

Notice the spark arrestor (left) and arming switch (to its right). Spark arrestors are very effective in eliminating spark-generated pitting in the surface of the Deans connectors.

Notice the gussets added to stiffen the load path from the top of the motor mount through to the sides of the fuselage. Without these the motor could move vertically to an unacceptable degree. Prior to this upgrade the motor vibrated at higher revs!

Notice the servo's mechanical advantage built into the pushrod setup. The outstand of the connection at the elevator is 2.5 to 3 times greater than that at the servo! The same approach is employed at the ailerons. This approach gives the servos great authority, allowing them to hold the control surfaces very firmly and not wobble in the air stream.

This construction indicates a likely range of COG = 177 to 194mm back from the leading edge at the root. These figures straddle the joiner tube as expected.

Wing Span: 1746mm
Length: 1828mm
Weight: 4000grams ready to fly with 8S 4500 35C battery.
Wing Area: 56dm²
Wing Loading: 71.4grams/dm² - comfortable for this type of plane.
Wing Cube Loading: 9.54grams/(dm²)^1.5; - falls squarely in the Aerobatic zone for cube loading.
Essential Features:  - Electric Powered using:
   - 16x8 APC 2 blade prop.
   - OS Motor OMA-5025-375kv outrunner - Enough power for good aerobatics.
   - 120A YEP Opto Speed Controller.
   - 5S in series with 3S (4500 to 5000) 40c+ LiPo battery set. 2000 Watts available.
   - Both an arming switch and spark arrestor system are employed here.
   - No extra weight added to achieve COG. Battery adjustment used for fine tuning.
   - Running a separate 2S 1000mah Lipo through a switch and UBEC to the receiver.
Radio Setup:   - Spektrum DX7S radio.
  - Spektrum AR7000 (incl satelite rx) receiver.
  - Spektrum DS821 servos for ailerons and rudder. Very nice quality!
  - 2 x Hitec HS-225BB analog servos for the elevator. One servo was internally reversed so they could be Y joined and run off a single channel.
Positive Comments:   - Good looking plane!
  - Really floats quite well due to its relatively light wing loading.
  - A good price for this size plane.
  - After having flown about 20 times now I find this a very enjoyable plane to fly!
Negative Comments:   - Design faults:
   - Load path from the top of the motor mount to the fuselage sides is inadequate.
   - Undercarriage mounting plate is inadequate. After just one flight it started pulling out of the fuselage!

  - Manufacturing faults:
   - Covering seems to have been applied in a dirty workshop - lots of dents in the finish and a fair bit of rubble under the covering!
   - Wing rib components not well glued in place. Many had to be reinforced with additional balsa after finding lose bits floating around in the wing space after flying!
   - A lot of additional glue applied to the various structures, especially where inappropriate movement was detected.

December 2013 - Completed assembly of this plane and have flown about 20 times at Fagan Park (Feb-2014)

Red Spinner 75mm
Aluminium Backed

APC 16x8 Propellor

OS Motors OMA5025-375

YEP 120Amp Controller

DS821s used in Ailerons and Rudder

2 x HS-225BB
Elevator Servos
(One is internally reversed)


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