Blade mCP X

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The Blade mCP X is an ultra-micro flybarless collective pitch helicopter, designed for intermediate to advanced pilots, released in March 2011. It comes in BNF and RTF trims. Both include two Eflite 1S 200mAh 25c batteries, a single port Celectra charger with AC adapter and a 1S High Current Ultra-Micro Battery Adapter Lead.

The mCP X is completely assembled out-of-the-box, the only potential adjustment is to level the swash plate by adjusting the servo pushrods. The Flybarless system uses MEMS gyros and has no gain adjustment. The push-rods from the servos to swash are adjustable but the pushrods from the swash to the blade grips are fixed length, and because it's FBL there are no other pushrods or linkages to set up. The tail has a heading hold gyro that appears to hold well even in backwards flight (gain is also not adjustable). The tail motor is 6mm (same as the mSR and mSR X).

The battery uses the JST-PHR2 plug, which is larger than the plug used by the MSR and other UM models, and similar to the one on the UM-Beast (which has three wires).

The Ready to Fly version comes with the DX4e, which has been designed to be used with the mCP X and allows switching between flight modes. The 4 channel MLP4DSM transmitter sold with the mSR, mCX, etc is not suitable. The LP5DSM and HP6DSM are not supported.

The mCP X V2 is a minor upgrade, with an improved tail rotor (part number BLH3603), better (30c) batteries and rubber grommets on the swashplate arms - all of which were common users modifications. The circuit board has also been modified for cost reduction and FBL improvements, which has resulted in some changes to the manual.

Performance

The mCP X can perform flips, rolls, funnels and rainbows. It is not a true 3D heli, as it doesn't have the power to perform rapid tic-tocs but if its power limitations are considered it is a very capable helicopter. Both main and tail motor are brushed and long lasting, but upgrading to a brushless motor is an effective way to achieve better performance.

Poor collective management can draw more power than the battery can supply, leading to bogging and cut-off of the tail motor, which results in a tail blow-out and rapid pirouetting.

The stock (25c) battery lasts for about six-and-a-half minutes of hovering. There's enough for three minutes of hard aerobatics, after which there is still enough power to fly for another minute or two but not enough for continuous hard aerobatics. With a better battery you can do continuous flips for 4 minutes.

Skill required

The mCP X is not a helicopter for beginners. It is more responsive and fragile (due to higher headspeeds) than Blade's Fixed Pitch and Coaxial helicopters (e.g, mSR X, 120 SR, mCX2) which makes it unforgiving to inexperienced pilots. Coaxial helicopter pilots, in particular, should probably fly the mSR, mSR X or 120 SR before the mCP X.

Pilots experienced with FP helicopters should be prepared to re-learn how to hover as the mCP X lacks the self-stabilizing tendencies of the 45° flybars on the mSR and 120 SR, and of coaxial helicopters. Unlike those helicopters, the mCP X accelerate away quickly if not corrected, and will not return to a hover when the cyclic is released.

Pilots who have flown small FBL FP helicopters or those with conventional (90 degree) flybars will be able to hover the mCP X straight away but adjustment will be required to the mCP X's sensitive controls.

Indoor flight is achievable due to the precise controls; however, the mCP X will accelerate quickly out of control so learning maneuvers indoors is not recommended. A larger airspace like a small park is a better venue for learning. As it allows time and space for pilots to learn to correct their errors (as opposed to simply crashing).

Taming the mCP X

The mCP X's aggressive tendencies can be calmed to make it more approachable for inexperienced pilots:

  • Spend some time learning to hover a CP heli in a simulator. Practice using Throttle Hold before you crash (do not chop the throttle, or you will drill the helicopter into the dirt).
  • Setting the pitch curve so that zero pitch is at low stick (i.e., pitch curve: 50-62.5-75-87.5-100) will make the collective less sensitive, but this will impact muscle memory development for inverted flight in the future.
  • Set your Dual Rates to 50% instead of the 70% recommended (leave the expo at 30%), this reduces the total possible roll rates and makes the helicopter feel more calm.
  • Consider some training under-carriage, it'll help keep the heli the right way up when you have to 'land in a hurry'.
  • Don't attempt your first flight in your living room, take it outside or to the park on a calm day; it's far more sensitive than the mSR and minor mistakes will send it flying away at high speed. When this happens, hit throttle hold before it hits the ground and the grass will be a lot more forgiving than the hard surfaces indoors.
  • Once hovering is mastered, forward flight should be taken gently at first, as the mCP X is more sensitive - you certainly won't be holding full cyclic like you do with the mSR! The mCP won't slow down on its own, just give it a nudge to get it started and another to stop it (and be ready to adjust the collective, it'll climb sharply if you stop suddenly).

Stability

The 120 SR and mSR have a flybar that counter-acts uncommanded inputs (wind, etc.) and damps cyclic inputs to impart flying stability, the 45-degree flybar on the 120 SR and mSR also brings the helicopter to a halt and maintains a hover. The mCP X will not hover hands-free, its FBL gyros will attempt to hold the heli at the last commanded attitude rather than stabilizing towards a hover. If this attitude is a fraction of a degree away from horizontal, the heli will have a constant acceleration in that direction and need a control input to stop it and bring it back, and another to cancel that movement. In practice, all CP helicopters require regular small control inputs to hover.

This does make the helicopter harder for a new pilot, but it makes it much smoother in forward flight and less affected by turbulance. The mCP X flies like a much larger helicopter thanks to the FBL system, and will fly well in a 10-15mph wind (enough to overpower an mSR or 120 SR). Gusts will knock it up and down, but won't disturb its attitude.

Aftermarket parts

Main article: Blade mCP X aftermarket parts

There are a wide range of aftermarket parts available for the mCP X: batteries, metal head parts, carbon fibre frames, color blades, canopies, etc. These upgrades range from must-have (extended tail booms) to just-for-looks (canopies, some metal parts).

Batteries

Main article: Blade mCP X batteries

The stock E-flite batteries are acutely underpowered in the v1 version of the mCP X. The 30C batteries shipped with the v2 are improved, but there are a wide range of higher-quality aftermarket batteries available which can improve flight times and performance. The Hyperion G3 CX 250mAh batteries are one of the most popular, as they are reasonably priced, very durable, have good power output, and are designed specifically for the mCP X so require no additional soldering or modification. The HobbyKing Nano-tech 300mAh batteries are also a popular choice, being cheaper than the Hyperions but they lack their durability and longevity.

Silicone O-rings

Main article: Blade mCP X O-rings

Silicone O-rings can be used as dampeners between the various head and swash parts to reduce play and improve responsiveness. There are 4 sizes of O-rings which can be used on the mCP X:

Brushless conversion

Main article: Blade mCP X brushless

The mCP X is arguably slightly underpowered in its stock form, with head bogging and tail-blowouts being two of the most common complaints. Installing a powerful brushless motor is an excellent way to improve performance. Recent developments in the BLHeli firmware and aftermarket parts market provide a wide range of options for performance and price, with governed headspeeds in the 8000-10000 RPM range achievable with the right motor and ESC.

Known issues

Main article: Blade mCP X known issues

There are a number of known issues with the mCP X, although most of the serious ones have been fixed in the current (v2) version. The most common and noticeable of which are:

  • Main gear slipping down the main shaft during crashes. This leads to vibrations and too much negative pitch if the main gear isn't re-set. Simply press it back onto the shaft (making sure the d-notch is aligned properly) to re-set.
  • Shake in flight which is generally caused by vibrations from damaged parts and dirty servos.
  • Tail blow outs which were more common with the v1 tail blade, but are still easy to induce with poor collected management. There are a variety of remedies to the lack of tail authority, including extending the tail boom, and replacing the stock motor with a larger 7mm motor.
  • Too much negative pitch out of the box. This can be cured by zeroing the pitch properly by adjusting the servo pushrod lengths.
  • Switching out of computer mode when modifying pitch and thottle curves outside of recommended parameters. Rebinding with Yaw held to the right changes the mCP X V2 back into computer mode.

Spares

Almost any part could break in a crash but if you want to buy some spares in advance, these are the most likely to need replacing, with the corresponding references:

  • BLH3502: Tail boom (can be replaced with 2mm carbon rod, which is stronger)
  • BLH3509: Swash plate (in particular, the rear ball breaks off, because its pushrod doesn't have a Z-bend)
  • BLH3504: Skids
  • BLH3505: Frame (the canopy mounting pegs)
  • BLH3510, BLH3511: Blades
  • BLH3514: Blade grips
  • BLH3522: Top links (90 deg twist dog bones, package of 8)
  • BLH3513: Feathering shaft (comes with head dampers and washers)
  • BLH3603: Tail rotor propellor (old version was BLH3517)

Other items you may want are extra batteries (EFLB2001S30), and if you're using the mSR 4 port charger then you can get leads that will allow you to charge the batteries on the celectra. The main and tail motor will probably wear out eventually but seem to have a very good life (similar to the mSR).

The canopy mounting pegs on the frame can be fixed by melting a hole in the middle of both sides with a hot pin and glueing a short length of the pin in the hole when you put the two pieces back together.

Setting pitch limits

Fold the blades back towards the tail. Zero pitch is when the tips are in line. You can determine other pitch angles by measuring the vertical distance between the blades and using this table:

Pitch Vertical distance at tips
3.8 mm
7.5 mm
11.3 mm
15 mm
18.8 mm
22.5 mm
26.1 mm
29.8 mm
33.4 mm
10° 36.9 mm
11° 40.5 mm
12° 43.9 mm
13° 47.3 mm
14° 50.7 mm
15° 54 mm

Although you can also just check zero pitch and adjust the limits to the maximum pitch before the rpm bogs and the tail breaks out.

Specifications

Main Rotor Diameter 245 mm (9.65 in)
Length 235 mm (9.25 in)
Height 93 mm (3.65 in)
Tail Rotor Diameter 36.5 mm (1.4 in) (v2 is 38.1 mm)
Weight 45.5 g (1.6 oz)
Batteries 2x 200mAh 1S 3.7V 25C LiPo (EFLB2001S25) (40x18x7mm) (v2 has the 30C EFLB2001S30) (plug is the JST-PHR2)
Charger E-flite Celectra DC LiPo balancing charger and AC power supply plus High-Current Ultra Micro Battery Adapter Lead
Radio (RTF) Spektrum DX4e 2.4GHz DSM transmitter with 4 AA batteries

Binding

The heli has two different "modes" built into its 3-in-1 that are selected while binding.

  • The mode for computer radios uses channel 1 for throttle and channel 6 for pitch; flight modes and curves are done in the transmitter like a normal CP heli, and programming in the transmitter cuts the throttle when you activate throttle hold.
  • The mode for non-computer radios (DX4e and DX5e) uses just channel one for throttle and the helis built in throttle/pitch curve. Ch 5 does idle up, and channel 6 (bind switch) tells the heli to activate its built-in throttle hold. See below for some tips to set the helicopter in this mode.

In either mode, CCPM mixing is done in the helicopter, as is normal for FBL helis.

Binding to non-computer transmitters (DX4e, DX5e)

The binding procedure for non-computer mode is really tricky, unfortunately that's the mode most of the beginners will need to use. When done incorrectly, the mode will become or stay the computer mode, with the following symptoms:

  • the trainer switch moves the blades while they are not rotating (for instance, juste after having performed the binding procedure)
  • it's impossible to take off
  • the pitch is negative
  • the pitch becomes positive when holding the trainer button

Furthermore, there are several reports of cases when the mCP X will "forget" the non-computer mode after some flights.

To bind in non-computer mode, the procedure is presumably well-defined in the manual (see below for the links), but this manual forgets to mention a very important point: the timing matters! Make sure you move the rudder control stick to full left after the transmitter LED lights flash exactly twice, release quickly the trainer button, and finally hold the rudder to the left until the blue light stays solid. Once this is done, pressing the trainer's button at the end of the procedure will really bring the LED to flash instead of moving the blades.

Binding to Spektrum modules on Futaba computer radios

The binding procedure for computer radios as detailed in the mCP X manual is incorrect, at least for Futaba computer radios using Spektrum modules. As presented in the manual, the steps for the computer radio binding will bind the mCP X to the Futaba computer radio in a non-computer mode. The correct procedure for binding the Futaba computer radio with Spektrum module is:

  1. Disconnect the flight battery from the helicopter
  2. Power off the transmitter and move all switches to the 0 position
  3. Connect the flight battery in the helicopter. The 3-in-1 control unit LED flashes after 5 seconds
  4. Put the transmitter in bind mode while powering on the transmitter
  5. Hold the bind button until the blue LED on the 3-in-1 control unit is solid. (this can take 5-10 seconds)
  6. Disconnect the flight battery and power the transmitter off

NB if using the T9CP Futaba radio, use swash SWH1.


Binding to Spektrum computer radios

To switch the mCP X to computer mode (changing from non-computer mode, for example) when binding to a Spektrum computerized radio (DX5i and above), hold the yaw lever to the right whilst binding to the heli, the led will go solid once successfully bound in computer mode. The full steps are:

  1. Disconnect the flight battery from the helicopter
  2. Power off the transmitter and move all switches to the 0 position
  3. Connect the flight battery in the helicopter. The 3-in-1 control unit LED flashes after 5 seconds
  4. Move the rudder control stick to full right and hold the bind button whilst powering on the transmitter
  5. Hold the bind button and rudder to the right until the blue LED on the 3-in-1 control unit is solid. (this can take 5-10 seconds)
  6. Release the rudder and bind button.
  7. Disconnect the flight battery and power the transmitter off

There have been some reports of the mCP X V2 accidentally going into non-computer mode/forgetting computer mode with LED flashing three times in a row and failure of motors to spool up. Rebinding with right rudder will re-enable computer mode.

References

Useful links

Sources of pigtails with suitable plugs for making your own batteries: (You can buy the plugs and pins very cheaply, but they're very fiddly and the proper crimp tool is extremely expensive)

Manuals