lightning bug

my first DJI Spark trials PART1

  • DJI Spark RTF
  • wheelbase: 170mm
  • FC, motors, RX, intelligent battery, RC: proprietary DJI
  • camera: 1/2.3″ CMOS, 12 Mpixel, FOV 81,9° 25mm
  • 3D obstacle sensing system
  • plastic, carbon fiber, 143 x 143 x 55mm (L x W x H), 300g
  • mods: reflective top cover sheeting, red propellers and propeller guards forward, heli landing gear with 4.2 Volt lipo, LED spots, multi coloured flashing LED strip, plastic protection of the camera gimbal

lightning bug from front japon

Modding the DJI SPARK / DJI SPARK mods

First nondestructive mod of the DJI Spark: Landing Gear & Spot Lighting – The lightning bug

also called “The SearchAndRescue mod”

1. Short description of the Spark
Much has already written about the Spark since it came out in the spring 2017. What I regard as especially amazing about the Spark are its technological capabilities at this small size. For example 3D obstacle sensing system, great hover stability even with no GPS, 1/2.3″ CMOS camera, effective pixels: 12 MP, 2-axis mechanical gimbal, intelligent flight battery and many intelligent flight modes (more when using Litchi as operating app).
A famost parallel in the history of technology, that I can think of, is the jump from portable phones to the smartphone.

lightning bug from below

2. The aim of the mods

  • landing gear for landing safely outside on wet or uneven / rocky surfaces,
  • flight direction visibility from below (red forward propellers and propeller guards),
  • improving flight stability in low light / darkness conditions with a LED illuminating ,the ground below,
  • visually enhancing an already charming drone with reflective top cover sheeting and a multi coloured flashing LED strip,
  • protecting the fragile camera and gimbal.

lightning bug from top night

3. The process of modding

– first the reflective top cover sheeting is cut to form and then carefully fitted.

– the plastic protection for the camera gimbal as well as the red propellers and propeller guards were ordered from a web store and after waiting for some time, attached to the two forward propeller arms for better visibility of the flight direction from below. (The two in back are the original dark grey ones.)

– after a tear down of a toy heli a useful part left intact is the very light landing gear made from plastic and aluminum tubing, which could be mounted under the Spark batteries. Using Velcro© fastener only, it would be possible to fit the same landing gear to all three batteries, keeping the Spark itself and the batteries unchanged.

lightning bug from neutral

– for flying in the dark (outside at night, darkness in SAR situations), I want to fit the landing gear with additional lighting: one LED spot as a head lamp forward to illuminate the forward direction, one LED spot as flood light downward to help the downward looking positioning camera make out the ground below and also for being able to see the landing spot in fpv flying.
The head lamp LED and the multi coloured flashing LED strip also come from the heli tear down and run on 4.2 Volt. After experimenting for some time with the USB 5V voltage output of the Spark, I decided to install a separate, light 4.2 Volt batteries instead, first to keep all of the Spark batteries for flying only and also to prevent shorting or otherwise damaging the Spark.
The little head lamp LED is fitted to a flexible plastic arm salvaged from an old analogue pocket torch.
The downward facing flood light LED is carefully extracted from a small but bright LED torch running on a 1,5 Volt AA-battery. Measuring the actual voltage reaching the high performance LED as 2,9 Volt I devise a simple voltage divider from 2 resistors to run it off the 4.2 Volts battery.
After all the wires from the battery to the different LEDs are soldered and protected by many layers of shrink tubing, the whole assembly is fitted to the landing gear with small cable ties and duct tape. Surprise, surprise, the LED spots shine bright as the day and cause almost no drain on the battery, which will be charged from the Spark charger via USB cable.

– voila, the little Spark is transformed into a SAR drone…!

lightning bug from below in the parkThe only problem is the limitation in the distance of the video transmission, which is very restricting – after only 60 m and a stone wall it is impossible to operate the craft in real time safely, due to strong video lag or latency. I am sure there will be solutions to this problem, like WiFi repeaters, the USB OTG fix or possibly the Parabolic Radar Antenna Range Boosters to be found on Amazon.
This seems to be a problem DJI has to solve, above all in order for the Spark to be able to assist in SAR missions, only its form factor would make possible….

more flying mods videos

lightning bug from above in the park
lightning bug from top

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