Post Flight

Nine broken props

It has been a week since the UK Drone Show agility competition and I've been going through the post flight analysis. The competition saw flights 6, 7 and 8 of the Diatone 250 Ghost Frame and the first three flights of it with the Taranis X9D transmitter, X8R receiver and Fat Shark FPV kit. The picture above shows the nine props that I broke in the course of the competition, mainly while trying to land on the top of the box and missing completely.

The damage to the vertical cable tie in the centre of the picture, which forms the mast for the CASA flag, was caused by one of the props clipping it in flight. You can see the black marks and the damage to the prop in the previous picture. This was the reason for my rapid abort and landing part way through the agility competition. 

The UK Drone Show Agility Course. The black ring isn't part of the course, but the other gates and boxes are.

The Diatone 250 Ghost frame with the blade guards and FPV kit, as flown during the initial two test flights on the Saturday.

The blade guards didn't survive the competition very well though. Our thinking went along the lines of, "we're only going to get one chance at this, so anything that gives us a margin of error is good". The two front ones were broken during the Saturday test flights and tested almost to destruction again in the competition on Sunday when I bumped into the box and then promptly fell off it, hitting the near edge and landing upside down.

Part way through repairing the two blade guards. That's 5 minute epoxy and gaffer tape.

One interesting thing worth mentioning was what I think caused the loss of radio connection when I was testing the quadcopter in the hotel room on Saturday evening. Having fixed the mechanical bits, I put it on the bed without the props on and went through all the electronic systems to see that it all still worked. It was a bit surprising when the radio link dropped out, despite there only being about 50cm between the transmitter and receiver. OK, so I now know the failsafe works and then the link re-established, only to drop out again about 30s later. It wasn't until the morning that I realised what the cause of the radio problems might be. When the sun came up and I looked out of the window for the first time, I was surprised to see an aircraft landing on the runway at Birmingham airport about 200 yards away. The radar tower is even closer, so I think this caused the radio issues as I've seen similar things happen before. As the radar sweeps through 360 degrees, the beam passes through the hotel room every 30s and disrupts the electronic equipment. Usually you can hear this sort of thing as a blip of noise when you're using a phone. It just makes me wonder whether this was causing the problems during the FPV racing as the NEC was on the other side of the airport?

I've also started getting the QuadSim code ready to release, but in the meantime, I had a go at building one of the FPV Nano Gates which I flew though on the agility course. This wasn't as hard as I thought, so it looks like it's going to be relatively easy to recreate the entire course in the simulator.

One of the FPV nano gates built using Blender.