R/C Park Flyer Gearbox Instructions

Power Drive 350+ (GPMG0253)

The Power Drive 350+ is suitable for for use in park flyer models up to approx. 17-1/2 ounces of total flying weight. The 5:1 gear reduction allows the use of large, efficient propellers. For you, this means high drive power with long motor run times. The power drive 350+ operates best with the enclosed APC 8x6 SlowProp and a 6-7 cell NiCd battery pack, preferably Sanyo N500AR. The following table highlights other meaningful combinations of propellers and batteries. The molded-in mounting flanges make installation in your model easy. Please read the assembly instructions and refer to the exploded view before assembling.

Propeller Number of Cells Remarks
APC SlowProp 8x6 6-7 N500AR For fast park flyers and aerobatic models like the Sukhoi SU-31.
APC SlowProp 9x3,8 or 9x4,7 6-7 N270AA For slow-flyers like the Pfalz, Spad and Fokker DR1.
Also well suited for indoor flying.
APC SlowProp 9x3,8 9x4,7 6-7 N500AR Extra performance for slow-flyers like the Pfalz, Spad and Fokker.
Recommended for experienced indoor modelers.


  1. Filter the motor (1) with the enclosed capacitors (6). Solder three capacitors to the motor. One each between the power terminals and the motor housing and one between each terminal. When soldering the capacitor leads to the motor housing, be sure to clean the area to be soldered by using a small file or sandpaper. The leads of the capacitors need to be as short as possible.
  2. Solder your ESC directly to the motor terminals. Refer to the diagram for proper polairity.
  3. Install the pinion gear on the motor. Gently push the motor into the Gearbox case. Insure you don't push the motor into the case too far by turning the prop hub by hand. If it binds or doesn't engage the motor pinion, adjust by gently moving the motor in or out of the case.
  4. Install the propeller (4) onto the prop shaft. Install the prop nut (5). Securely tighten the nut, being careful not to over-tighten. Again check the operation of the geardrive by turning the prop by hand.
  5. Attach the assembled geardrive to the model with the enclosed screws (7).
  6. Plug the ESC into your receiver. Attach the battery and briefly test the operation of the gearbox and motor Note: Despite the relatively small size and power of the gearbox, danger of injury exists because of the sharp propeller blades. Check that the prop is turning in the correct direction and that it is not vibrating excessively. A good way to balance the prop is to apply a small piece of adhesive tape to the back of one of the propeller blades. If the imbalance becomes worse, move the tape to the other prop blade. Determine by further test runs and variously sized pieces of tape the required size of the tape, until the drive runs vibration-free.

Lubricate the large gear with the appropriate lube (Ecolub # 130,004 0 recommended) After approx. 5-10 flights the gearbox will run more easily and more quietly, especially after lubricating the gears.

Installation and cooling

Install the receiver as far as possible from the ESC and motor. The motor must be cooled by sufficient air supply. Be sure to allow the motor to cool after each flight.

Safety notes and preventive measures

  • The motor is appropriate for typical Park Flyer models.
  • Check all mounting screws for tightness. All wires and connections need to be properly insulated to prevent short-circuits.
  • Do not overload the motor. Overloading leads to overheating and can damage the motor.
  • When the motor is operating, please stand clear of the arc of the propeller.
  • Do not stall or block the motor. The high current draw can lead to a damaged motor and the battery pack. If the motor is stalled or blocked for an extended period of time, it can get hot enough to be a fire hazard.
  • Use of an ECU with a soft start feature is highly recommended.
  • Check the prop and battery for nicks or damage often. Especially after a rough landing.
  • Do not operate the motor in the proximity of magnetically sensitive devices (clocks, cardiac pacemakers, data storage devices, music cassettes etc..)