E-flite Blade mCX
This model was introduced in the fall of 2008.
The lower rotor has two servos driving a swashplate for full cyclic control, the fixed top rotor is connected to a flybar set at a 45-degree angle to the blades; such a setup tends to add more stability than a 90-degree setup. In typical coaxial fashion, the rotors each cancel the other's opposite rotation, making the mCX stable enough so that even first-time R/C users quickly learn to hover.
See also: Force RC
At only 7.5" long and weighing less than one ounce, the mCX is comparable in size to toy-grade, two-channel infrared-controlled helicopters but is far more stable and maneuverable with a more dependable radio link. The mCX has more accurate yaw control and is better able to maintain both speed and direction in any control axis.
As with larger coaxials, the mCX is so stable it might be more accurately labeled an "air car" than a helicopter, as the pilot can more or less "drive" it through the air rather than having to actually fly it, as is necessary with the larger fixed pitch and collective pitch machines, like the HoneyBee FP, E-flite Blade CP, T-Rex, etc.
A new five-in-one on-board control unit contains two miniature servos which control the cyclic functions, i.e., aileron and pitch.
The five-in-one also contains the receiver, gyro and two motor speed controls.
The mCX can be flown in a six-foot (2m) square area or smaller by experienced pilots. Forward flight is limited due to the coaxial desing and the model is crash-resistant because of its low weight. Therefore, even a 12x12' area (4x4m) will be adequate for the novice pilot.
E-Flite recommends that this model be flown indoors only. Like most coaxials, the mCX cannot handle even the slightest of breezes.
The cyclic and rudder controls make the heli controllable in all directions of flight and the model can be quite precisely flown. Spot landings within a two-foot radius or smaller are achievable with some practice.
A tandem version is available as well. The Blade mCX Tandem Rescue (EFLH2500) joins the mechanics of two mCXs on one frame and is topped with a scale rendition of a Canadian rescue helicopter with working navigational lights.
- Rotor span: 7.5"/190mm
- Weight: 1 oz/28g with battery
- Length: 7.9"/200mm
- Included radio system: Four-channel 2.4 GHz DSM2
- Main drive motors: Micro coreless (2 installed)
- Standard battery: 3.7v, 110mAh 1s lithium polymer
- Onboard control electronics: E-flite 5-in-1 control unit
- Flight duration: 5-8 minutes per charge
- List/street prices: US$129.99
- Catalog number: EFLH2280
Problems and fixes
Lower rotor won't spool up
If after a crash, the lower rotor will not spin up or spins at a slower-than-usual rate, the motor connection at the five-in-one board may have worked loose. Gently apply pressure to ensure the motor connector is fully engaged.
Shortened battery life
Users on hobby bulletin boards have reported that the crimped battery connector pin joints can develop higher resistance, leading to early low battery cut-outs. This can be fixed by adding solder to the joints. However, this requires careful soldering to ensure that the connector pins still fit into the connector housing.
Tendency to fly backwards and/or unstable flight after a crash
The swashplate's anti-rotation pin can seperate after a crash or hard landing or the swashplate itself can separate, leading to non-centered controls. The swashplate can be easily pushed back together but once this happens, the problem tends to recur.
Yaw will not stay in trim
This can be caused by a weakened motor. Try switching motors temporarily (with care since the shaft lengths are different) and see if the problem reverses. Replacing the motors should fix the problem. Refer to the shortened battery life issue above, as yaw trim often drifts at low battery voltages.
Upgrades and modifications
Increasing forward speed
- Some users have adjusted the length of the servo pushrod by disconnecting the links and rotating the ball link socket in order to bias the heli to forward flight via slightly extended ball joints.
- Others have shortened the flybar to reduce the stabilization provided by the upper rotor.