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The Compy300 is a micro helicopter made by J-TEAM in Hong Kong. The Compy is named after the Compsognathus longipes, a smaller version of the Tyrannosaurus Rex.

As of mid 2010, the manufacturer stated that the company was "under reformation due to some law suit so the [parts] supply is not stable"


  • Length:500mm
  • Main rotor: 550mm
  • Tail rotor:140mm
  • Flying weight: 390g - 470gram
  • Gross weight: 195gram
  • Main gear: 140T
  • Belt Gear: 40T
  • Tail Gear: 11T
  • Head/Tail Speed Ratio: 3.63
  • 3s 1000-1300 mAh 15-20c battery

It uses a 3mm main shaft, so the rotor head is compatible with the Esky CP2, blade CP and CP Pro and several other micro helis and a number of alloy rotor heads. Many of the CP2 head parts are interchangeable with the Compy.

It uses a cut down T-Rex tail boom, unlike most helis in this class that use motor driven tails. The tail parts aren't all exactly the same as the T-Rex, but because the boom is the same diameter, you can fit a whole T-Rex tail. The main differences are that the T-Rex uses larger balls on the blade grips and doesn't have a ball on the pitch slider. It is possible to glue a spare Compy ball onto a T-Rex SE pitch slider to make it fit.

The standard frame allows all 3 servos to rotate in the same direction, which in theory avoids CCPM interaction.

There is also a carbon frame, which is stronger but heavier and doesn't have the servos rotating in the same direction.

A popular ESC is the 30A dynam (CC ESC's are nice, but pricey and the 20A dynams are trouble) The Hyperion 20A Titan ESC is not quite fast enough in governor mode (2100rpm maximum).

The stock rotor head and stock blades are good and HDX CF 255mm blades are also popular.

Recommended pitch range is 10 degrees each way.

The recommended max head speed is 2200rpm, but 2500rpm is much nicer to fly (and it doesn't fly apart)

Compy V2 preview!


  • The preferred motor is the 400DH (Kv: 3800kv) with a 9 tooth pinion.
  • The AKE 450R35LT (Kv: 3500rpm) is also recommended by Aero-Fever, and needs a 10T pinion.
  • The ARC110 /10T works well but gets hot, even with a heat sink.
  • The ARC130 /8T was ktm520's favourite
  • The HDX300 also fits.
  • Some also use the E-sky 3900Kv


Fibre frame

Fibre frame
J-Team also delivers a fibre frame with much tougher landing gear. This is only 13g heavier than the stock frame and a lot stronger. It looks like carbon fibre, but is actually coloured fibreglass.

Although this frame was designed for the CCPM Compy300, is also supports two servo FP heads and is a popular choice for belt tail FP micro helis.

The servo arrangement is different to the stock frame, with the tail servo under the boom and the rear cyclic servos stacked behind the main shaft. This means that you need a few other parts:

  • A longer carbon push-rod for the tail servo,
  • A longer push-rod for the lower cyclic servo. The long push-rod from the Compy head is a good fit for this, if you fit a spare ball to the servo arm. (Actually, the frame kit received from cy-model did include the longer rod and a ball link.)
  • A slightly shorter main shaft, you can either cut down the stock shaft, or order the 80mm shaft, or go for the one-way bearing (which, in this frame, uses the stock shaft with an extra hole).

As an alternative, the tail servo can be mounted on a boom clamp.

amf14's Compy Fiber Frame review and build log.

If the instructions are missing you can find it here

The fibre frame is almost identical to the Guru-Z Neon, and many parts are interchangeable, and easier to source.

Auto-rotation one way bearing

This needs a longer main shaft with an extra hole. A number of people have had problems with this, and a heli this small and light will not auto-rotate well.

CP2 main gear

This is often fitted as a replacement because it's available locally, but it doesn't have the pulley for the belt. You either need to find a separate pulley (i.e. from the HDX300) or cut out the pulley from your old Compy main-gear. If you have the auto rotation set the CP2 gear is a direct replacement without any modifications.

Replacement heads and blades

There are a number of alloy heads and carbon blades that fit, mostly designed as upgrades for the CP2. The TRex metal tail case can be used, but makes the Compy a little tail heavy.

TRex carbon tail blades are a good way to add more power to the tail.

Plasti-Blades tend not to break in a crash.

ktm520 has fitted metal balls on the mixer arms but it can cause binding

The Esky Honey Bee FP head and shaft will fit the Compy 300 to make a FPBD heli. Guru-z asymetric blades are a good choice for this. The Honey Bee blades produce too low a head speed for a good tail-hold. The swash guide should be shortened to avoid possible clashes with the fly-bar.

Main shaft lengths

There are 3 different lengths of main shaft for sale, depending which frame you use and whether you have the stock main gear (that is fixed to the shaft) or the one-way bearing autorotation main gear.

80mm (2 holes):

  • For Compy FP
  • For Compy + G2 Fiber frame with fixed main gear

86mm (2 holes... the stock one):

  • For Compy with stock frame with fixed main gear

86mm (3 holes):

  • For Compy + G2 Fiber frame with one-way system
  • For Compy with stock frame with fixed main gear (just ignore the mid hole)

93mm (3 holes):

  • For Compy + stock frame with one-way system

If you're making your own shafts, the distance from the centre of the hole to the end of the shaft is:

  • Bottom hole : 2.25mm
  • Top hole : 4.0mm
  • The auto-rotation pin is 11.5mm above the bottom hole (centre to centre)

All holes are 2mm diameter (a #53 drill)

Common problems

Tail slider needs to be almost all the way out to hover. You have the tail blade grips reversed. Turn them around and the tail slider will be in the middle of the shaft when you hover. The arms of the grips should point in the direction of the leading edge of the blades according to the instructions, and rotating anti-clockwise when seen from the starboard side. Note that the screws must be entered from the back side if you want to pinch the blade grips. The blades should be free to move though.

Tail is not powerful enough, heli pirouettes at maximum power Check that the belt is tight enough. Hold the main gear and check that you can't turn the tail by hand. Check that your maximum pitch is not excessive and that your head speed is high enough.


Low Budget

  • Gyro - Telebee HH, Esky HH, or even HK401B
  • Tail servo - TowerPro SG50
  • Cyclic servos - TowerPro SG90 or E-sky 8g
  • Battery - 1000mAh 11.1V (3s) Loong-Max
  • ESC - E-sky or Turnigy Plush 12A
  • Motor - E-sky 3900Kv or HDX

High Budget

  • Gyro - Logictech 2100
  • Tail servo - Futaba 3154
  • Cyclic servos - HS65
  • Batterym - 20c 1300mAh for sport flying and 1000mAh for 3D
  • ESC - 20A with governor mode and 3A BEC

Component Weights

  • compy auw - 375g
  • compy plastic canopy - 12.4g
  • compy fg canopy - 25.3g
  • logictech 2100T - 9.7g
  • compy skids - 13.5g
  • 22E skids - 13.8g
  • superskids w/adapter - 23.0g