UPDATE 1/1/2017 Due to new legislation about drones I cannot fly my drones any more because they need an airworthiness certificate from Hellenic Civil Aviation Authority. Never mind, the costly Li-Pos are already exhausted and I thing it is about time to move my autonomous vehicle interests to other more legal regions :) .So far so good then, I learned a lot about autonomous vehicles and most certain I HAD A BIG FUN FLYING THEM (and a huge aerial photo collection).
Ok let's admit it. Can somebody who likes microprocessors, GPS's and high tec electronics stay away from drones? Nay !!!! So I entered this uncharted region plenty of fear due to the fact that I had once lost a model airplane due to my ignorance of how to fly model airplanes. However I have no fear at all to make a car - ship - airplane - drone -submarine - whatever. So I acquired some aluminum plates, bars, tubes and 3mm inox allen screws and bolts, purchased from E-bay motors , propellers, batteries , autopilots ,GPS , telemetry modules and here it is.... my first drone back in 2013 IN FLIGHT !!!
First quad in flight - RIP
RIP ??? How's that ? Well , I went totally unprepared, without on board pilot camera, no video link, just a simple short range bluetooth telemetry, a 1HZ GPS module (the late EM406) which took for ever to lock , no failsafe programmed on autopilot, on a windy day to a mission which seamed very easy, very close to my house. Failsafe was a nuisance to program and once the quad returned to launch (RTL) on his own and crashed before I understand what happened. I flew it without gps lock and when it got over 30m it drifted away due to strong winds. I tried to bring it back but since I had no colored stripes (or colored propellers) on any of the arms to know where it was heading , I drove it further away and it just disappeared from view towards a hilly forested area. Needless to say that my flying skills were (and still are) NULL.
"Even if you fly in a totally bushed area your drone is going to crash on that single rock between the bushes." The frame below shows the propeller blade separating and causing a drone crash. At first I thought that responsible for the crash was some kind of RF interference. The on board video camera caught the culprit : We had an in-flight propeller blade separation.
After considering more seriously about flying drones I assembled the MKII. It still flies today (2016) despite a few crashes that costed me no more than a few propellers and some twisted aluminum arms and plates. Here it is:
- Don' t use cheap 9.6 inch propellers on a 1.5kg drone - they use to flip on air (happened to me twice).
- Cheap batteries have unexpected behavior .
- Use video link and a camera for the pilot
- Wind velocity rises dramatically 30m or higher or when clear of trees or houses.
- Schedule your mission very carefully
- Be sure that telemetry and osd video are working
- Do a range test
- Check for RF interference
- Program failsafes
- Wait for the gps to lock.
- Stay away from people -cars -airplanes and generally urban areas - 1.5 kilos is not a negligible weight when falling from 70m
- Do preflight tests based on a thoughtful prepared list
- Connect the battery low warning buzzer
- Put a lost model module buzzer on an unused channel
- Write you phone number on the drone.
- Use different color for the drones back arms.
- If you 're not a competent pilot, then let the electronics fly it for you - believe me they can do it both economically and safer too.
- The drone should have ample space for the onboard electronics and they must be accessible without major strip down.
- Video camera - the excellent Mobius actioncam - should be on a proper gimbal offering unobstructed front view and placed well away from the propellers.
- The drone must be foldable and could be easily carried in a plastic tube of 15cm diameter.
- Battery must not hit the ground, but it must be housed and protected inside a frame, and able to be moved to adjust the CG of the air-frame. (this is accomplished by using velcro straps)
The new drone named MARK V (MK V) was designed back in 2015 from scratch using a CAD software .
3mm and 0.8 mm aluminum was used for the baseplates and 1x1 1.2mm aluminum "Pi" frame for the arms.
Notice the orange colored tape on the back legs .....
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CAD of quad MK V
CAD of quad MK V
Quad MK V