Here East Summer School at the Queen Elizabeth Olympic Park

We ran the second Drones4Good workshop of the week as part of the Here East Summer School at the Queen Elizabeth Olympic Park. That's two workshops with a turnaround time of 4 days, which is the fastest we've ever done. Basically, if we destroyed all the kit on the first one, then the second one wouldn't have been possible, so it took some organisation.

The video above shows the space that we were in. This was taken using the HubSan drone camera, so the quality isn't great. It was done in rather a hurry too, as there were people wanting to get their hands on my drone. As you can see, though, it's quite a big space with a very high ceiling, which caused quite a lot of damage. We also discovered that the floor is made from a strange type of metallic tile as the motors were sticking to it. This didn't seem to affect the calibration of the flight controller's sensors though.

These are the frames with the Top Trumps cards. You can just see the Lima animation on the screen in the background.

We had 13-16 year olds for this session, so I wanted to make it a bit more fun and came up with the idea of Top Trumps for drones. Usually, we just lay out all the frames and it's a bit arbitrary which ones they decide to build. Over the weekend I had the great idea of making Top Trumps cards with the different features of the frames on them. The mass is very scientific as I weighed all the frames I have at home (and I have a lot) to get an average. There's more variation in each unique design than I first realised due to differences in the 3D printing process and filament. The MakerBot is definitely lighter but the Ultimaker is more accurate. Anyway, by adding features like "flying difficulty", "building difficulty" and "crash resistance" it gave them something to discuss when they were choosing which frame to build. Admittedly, I did just make these numbers up, but then, I've flown all the frames more than most, built all of them more times than I can remember and seen all my hard work repeatedly crashed into walls and floors.

Drone Top Trumps - if you want to make your own, it's easy in Powerpoint

We didn't have any opportunity to see the space beforehand this time, so we had no idea of how big or high it was going to be. The end wall turned out to be the biggest problem as it shredded most of our props. The height was the next problem as it gave gravity more time to do its work. This is the first time that we've seen drones hitting the ground hard enough to smash the motor armature right through the back plate so that the core and windings fly out of the metal case. Usually they just break the wires off, but this was damage on a different scale.

The Dragonfly3D was a bit too much for most to handle. That's the motor core that should be inside the metal casing of the broken rear yellow arm. What causes this is hitting the floor inverted from 20 feet.

However, this was one of the most fun sessions that we've ever done. The students were really interested in taking stuff apart to find out how it works. I only took two HubSan controllers with me and no dual control, so it was chaos, but not on the scale of the events where we've had six flying at once. Maybe if we knew how big the space was, then three flying would have been better? We did end it with a bit of a queue of people wanting to fly with different frames and had to ration the flying time. But, then a lot of it didn't last for very long. The videos below show how we lost a lot of the equipment.




One of the students wasn't very good at coordinating the throttle, so, in order to give him a bit of a go at flying, I had the throttle and rudder and let him fly with just the ailerons and elevator. This does partially work, but his control inputs didn't really bear any relation to what the drone was actually doing. This was definitely a more challenging group than the last one. The photo below shows the survivors.

The survivors from the session. Note the two smashed motors near the yellow dragonfly. These are only the four damaged frames, flight controllers, motors and props as they ended the session. The full set of frames are in the next picture.

If you look at the photo above, the more astute might notice that there are only five flight controllers when we started out with six. This was because we declared one of the students a winner due to his excellent flying ability and gave him one of the frames as a prize. I think it was a butterfly with the flight controller and four motors, plus I gave him a few of the frames (H and X?). Looking at the frames left over, I can't figure out what happened, as my intuition says that we damaged many more frames than this. The damaged dragonfly 3D, dragonfly II and two H frames are above, but we must have smashed many more than that, surely? This is the surviving frame count (minus what I gave out as a prize), so it's missing 2 CASA X, 1 H Frame and 1 Butterfly, which I'm assuming I gave out as the prize:

Did we we really break so few frames? No butterflies, bees or ghosts died during the making of this workshop.

Incidentally, the second yellow dragonfly 3D also survived unscathed, mainly because they never tried to fly it. Looking at the videos of the event, I can see what happened to the Dragonfly II, Dragonfly 3D and H Frame, but no other frame damage is obvious. Usually we break at least one butterfly in half or shatter the wing. I don't pay much attention to the frames as they're considered throw-away items. All I do after each session is to count the flight controllers and batteries and do a rough estimate of motors, plus a check of any other expensive items. For the record, I still have 13 usable frames at the end, and it's always the props and motors which are the determining factor. I seem to have 31 working motors left, with 8 "B" props and "22" A props, but that's before doing a full check. It looks like about 8 motors were damaged during the workshop and 16 props, but the props have all come back in bits, so it's difficult to know how many there were before. A lot of them disappeared, never to be seen again.

OK, so that's another successful session completed. Now I go into a post flight mode where I cycle all the batteries and put them into a storage state for next time. All the kit then gets dismantled and tested before being packed up ready for use again.

Thanks again to all the helpers, Valerio, Farzaneh and @en_topia, and also Diane and Elpida from @UCLEngEdu for inviting us, along with Here East who organised the whole two week summer school.

Spot the drone? This won't end well.