Crazy Last Days of Summer

IMG_20170924_121344.jpg

 

The weather seems to have got the memo this week and we had warm sunny conditions with enough breeze to hand launch an autogyro. You can see from the picture how I’m stopping the blades from spinning with a rucksack.

It was crazy this week as I think everybody saw this as probably the last good day before the weather turns Autumnal. We had three drone parties in various positions around the field not talking to us in the middle. One was a father and his two kids with a toy drone (Syma?), another had a more professional one at the opposite end of the field, while the third was a couple I’ve seen most weekends with a Mavic. They were right in our landing zone, which wasn’t great. As for everybody else, there was a guy flying a Mavic when I arrived, plus someone I’ve known for ages on his bike with a UMX Fokker DR1. Shortly after this we had the guy with the Cobra, along with his son and daughter, then the Skysurfer, a guy with a DLG from a couple of weeks ago and a lady with a micro drone and FPV. Finally, towards the end we had another two guys from last time with another Skysurfer (or Bixler?), a small helicopter and a drone.

As for flying, in order of take-offs I flew: the Fokker DR1, the Skysurfer, my ATOM Autogyro, my RS352 and finally my 3D printed Dimorphodon quadcopter. The DR1 was a bit of a handful in the wind as flying a 30g box kite on a windy day is always interesting. Anyway, it was really pitching up badly this time, which I can’t remember it doing when I first flew it after its front end repair the other week. I ended up putting in about 10 clicks of down elevator, but I think it’s partly thrust line as things definitely improved when the motor was off. I did some fairly impressive vertical aerobatics while I was busy hitting the down trim, but then the motor wouldn’t come back on, I tried going back to zero, then 100% to clear the ESC, but there was no power so it was time to land. Back on the ground power seemed to be restored, so I can only think that the aircraft had had enough and decided it wanted to be on the ground more than getting blown about in the air.

Next up was the Skysurfer which I did the maiden for a few weeks ago and thought was an absolutely wonderful aircraft to fly. This time, the launch was a bit too interesting. I elected to hand launch and fly, but once I released it, the aircraft dived into the ground. There was a moment when I would ordinarily have cut the throttle, but the motor’s at the back and up top, so I just bounced it off the ground and slid my way into the air. This time out it was pitching down badly. Why I’m not quite sure as it had only had its wing fixing improved since last time out. Anyway, I got it sorted with about 10 clicks of up elevator and a bit of right, then let the owner have a fly. It wasn’t liking the conditions much, as it felt a bit spirally unstable in a tight left turn. It still flew well, though and the owner had a few more flights on his own too. – NOTE: it occurs to me afterwards that I’ve just flown one aircraft that was pitching up and needed me to fly with 50% down elevator, then switched straight to another plane that was pitching down and required me to fly with 50% up. It’s all good experience.

 

OK, so I fixed the ATOM autogyro yesterday and now it was time to fly it. One alteration that I made was to put the receiver on the rear wall of the pod rather than inside, as the internals are rather busy. Facing into wind and holding the nose vertical, I waited for some significant spinning to happen. Sure enough, it started humming and the wheels started to vibrate, which is the signal that the rotors are spinning fast enough to launch. But, it failed to really fly. I find myself having to tilt the rotors forward to prevent it going over my head, it flies away from me, but never seemed to be really on step enough to gain height. I had three attempts and every time it flew forwards, rolled and yawed around to the left, lost what little height it had and hovered in for a landing having not quite completed a full circuit (at about 10 feet height). I’ve switched to a 9×6 prop from a 9×4.5 to try and give it a bit more bite, but it hasn’t made any difference. Also, I’m using 0.8mm shims under the blades, but I did this as two 0.4mm shims on top of each other. The top one was sellotaped on to make it removable, so the next obvious thing to try was to remove the extra shim and fly with just 0.4mm. This didn’t seem to make any difference, so I’m going to have to take this home and have a think about it. The aircraft has flown from a hand launch in this configuration (with a 9×4.5 prop though) as I had a 4 minute flight. My feeling is that it’s the launch and not getting into the right part of the flight envelope. The left bank on launch says to me that the rotors aren’t up to speed and then it never gets out of this stalled mode. I was flying with the throttle at 100%, but with no noticeable effect on airspeed, rotor speed or height gain. Something isn’t right here, so I need to do some more homework on how to fly autogyros.

After that I had three flights with the RS352. I’ve only just realised, but this aircraft’s birthday is around this time of year. I bought it in early October, but I can’t remember if it’s now 4 or 5. I’ll have to have a look, but I like to live with my aircraft for a long time. I don’t know whether it was my new charging regime, but the good LiPos which I put in for the first two flights just didn’t seem to have the punch that they normally have. I used the storage charge of 3.88v two weeks ago, then fully charged them Saturday night and used them without topping up on Sunday morning. Normally I would top up and fly, so that might be the difference? I was a bit preoccupied with the autogyro though.

Finally, I flew the 3D printed Dimorphodon quadcopter that I made a while ago. I’ve never had a real go with this until now, but it was a lot of fun. It’s based around the HubSan flight controller and I had to use Expert mode because of the wind, but it doesn’t fly like most other quadcopters. I always wonder how much is to do with how an aircraft looks, but with its odd shape and more aircraft like wings rather than being square like a quadcopter, it seemed to want to spin round on the spot. It was great fun to fly, but I need to do something about those pointy wing tips as I managed to stick one in the grass at one point. That can’t be safe, so I’ll round them off before I publish the STL file for other people to make.

One final thing is that I’ve taken two sets of photos of the autogyro in order to attempt a 3D reconstruction to build a mesh for my flight simulator. I did one inside and one outside, so I’ll run that once I get back to work. The more I get into autogyros, the more I want to build a simulator for one.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s