IMP Concepts DJI FlameWheel f450/f550 Stealth Retracts (DJI Arms)

Transcription

1 IMP Concepts DJI FlameWheel f450/f550 Stealth Retracts (DJI Arms) Introduction IMP Concepts retract system for the DJI f450 /f550 Flame Wheel Quad multi-copter series is a great compliment to your quad. The total height from the base of the standard DJI is 152mm or 6 Inches. This provides ample clearance for your FPV equipment. If 6 Inches is not enough for you, Custom units can be made to order in 1mm height increment increases. But adding too much height reduces the stealth effect of this great mod. Custom Parts Required: 4 x IMP Concepts Servoless retract arm mounting brackets. DJI Flamewheel F450 / F550 Mount for the Stock DJI Arms 4 x IMP Concepts Retract Legs (Available in Black & Blue) Perhaps Red and White Depending on demand. Black 126mm Leg Shown. Basic Dimensions:

2 Generic Parts Required: 4 x Servoless Retract Actuators (PZ or HK-15094M): Features, Specifications & Dimensions: Features: -10 seconds automatic electricity protective design to prevent overload and short circuit. - Double shock absorption design ensures best to the gear. - A musthave product for RC Heli fans. Specifications: - Color: Black - Storage temperature range: -20 C 60 C - Operating temperature range: -20 C 60 C - Operating voltage range: 4.5V-6V - Overall dimensions: 55(L) * 32(W) * 2(H) * φ3mm - Limit angle: 90 ± 1 - Item weight: 19g - Support Flight Weight (Each) 2kg. (2.2 Pounds) - Connector wire length: 7.2cm

3 Screws: 4 x 3mm x 16mm Cap screws with one side of the head ground flat. Any 3mm x 16mm screw can be used here, Cap screws are easier to grind. (See Photo). They are ground on one side to accommodate the offset of the servo trunion. (Use a Dremel to grind the side of the head flat, be sure to wear good eye protection) Ground 3mm x 16mm Cap Screw Example: 8 x 3mm x 12mm x.50 thread Cap screws or, 8 x 2mm x 12mm x.40 thread Cap screws The size depends on the servoless retact used. They can come with 2mm or 3mm retaining bolt threads in the metal trunion version. (These go one either side of the arms to hold them to the servo and also act as a grub screw to retain the shaft screw mentioned above). The Plastic trunion units should be tapped to 2.5mm by using a 2.5mm screw. DO NOT to let any swarf or debris to get inside the actuator mechanism as this can cause premature actuator failures. 16 x 1.5mm x 5mm Countersunk Head screws. These are the tiny countersunk screws that come with the retract servos (These are used to hold the stock mount that is discarded, they connect to the printed Arm mount mentioned above to the Servo, they only fit on the 12.5mm x 12.5mm spaced side. 1 x custom made or commercial 4 to 1 Servo Splitter. (See photos for examples of these) They are easily made from servo leads. You will need to make them long enough to reach your receiver or flight Control unit. (The 4 servos connect to this to provide one RX connection) There is no issue with power rating here as servo signals are just that, signals. Control signals and VERY, VERY low current in the MicroAmps). Mounting the Legs on the Servoless Actuators: The shaft retraining screws in the side of the legs should float freely in the legs and not bind with the plastic. You may need to ream the holes to fit the screws you are using. Please do not over tighten the shaft retaining screws as they are designed to function correctly with minimum force. Excess force may cause the actuators to strain and possibly damage them. If the actuator motor gets hot please stop activating them until the cause is determined and rectified. Fine tuning the fit by filing off excess plastic is sometimes needed for smooth operation.

4 Motor Mount & ESC Wires The stock DJI f450 / f550 use M3 x 8mm Motor retaining screws. We use the 2 rear to secure our mount. These will need to be replaced with M3 x 10mm screws as our mount adds 2mm to the length. We have actually built in 0.5mm so when the plastic is compressed by the screws they will not foul the motor windings, however we recommend care is taken not to over tighten these 2 screws as the plastic will compress slightly. As per DJI please use thread locker to secure the bolts not brute force. The ESC wires can be routed as desired there is room in the mount for the 3 motor wires to be routed from the front (Outboard) 2 holes in the arm as shown in the photos below. Mount Screw Detail

5 Installing Mount on DJI f450 / f550 stock arms It is recommended to install the servoless retract actuator before installing the mount to your quad. Important Note: Please ensure the motor screws are NOT too long as you can damage the windings on the motors if they are. DOUBLE CHECK THEM. Install Mount on Arm as shown in photos below: The tabs on the mount, will need to be firmly pressed into the arms and located in the corresponding holes, so the mount is flush with the arm s surface. It will need quite a bit of firm pressure. Once installed, simply press down into the holes in the arm and secure the mount with the 2 motor screws as explained earlier. They will ease into place, and are designed to be a little tight. They are NOT designed to be installed and uninstalled repeatedly. When removing remove the motor screws first, then place a thin flat object between the arm surface and the mount beneath the motor screw holes and ease them up one side at a time slowly. The ears on the locators can get damaged but even with one ear broken, the mount can still be used safely.

6 UBEC for Power to the Retracts (and any other Servos) Depending on your flight controller & receiver system, you may need a UBEC of 3amps in order to power the Servos, we used a Turnigy 3a switching UBEC powered directly from the battery, the gimbal power connector is ideal if you do not have a gimbal. Features: Over current and over heat protection. Switching frequency 300khz. 92% chip efficiency Noise reduction alloy housing Specs: Output: 5v/3A or 6v/3A (selectable) Noise: <50mVp-p(@2A/12v) Input: 5.5v-23v (2-5S Lipo pack, 5-15cells NiMh) Size: 41.6x16.6x7.0mm Weight: 7.5g If you are using a 3DR PixHawk flight controller, the UBEC Output goes directly into the PixHawk Power Rail. Any of these can be used. We used 5 as it was in the middle of the rail.

7 Example Splitter & Hub. Extensions may be needed to reach Flight Controller: We replaced the servo extensions with wires and soldered the extensions to the servo wires, but standard servo extensions can be used. The legs and retract assemblies are not designed to take a REALLY hard landing, but then nor are the DJI arms, we have seen many broken ones to know this. We have dropped out test quads (under duress to test our retracts) from about 1 ft or so on concrete and there were no ill effect other than the hard sound. We were trying to come up with a dampener of some sort but perhaps some ¼ door draft foam glued to the leg bottom would work. But hey we are supposed to land softly right, and on grass or something. The servoless retracts are said to have dampening qualities built in, but we would debate that. Now just set up your radio gear switch on your favorite radio and you are done. Example Gimbal Settings Using RC9 for the Retract Servos on the 3DR PixHawk any of 3 Channels can be used:

8 Sample Installation Photos on a DJI f450 / 550 Quad Arm:

9 Sample Installation Photos on a DJI f450 / 550 Quad Arm Continued:

10 Sample Installation Photos on a 3DR Iris Quad:

11 Go and enjoy your IMP Concepts Stealth Retract system. Web site: RCGroups Handle: The ShokWaveRider