A Heatwave, Then Gales

It was very hot yesterday, reaching 35 degrees in the shade. Today, a weather front has caused the temperature to drop ten degrees mainly due to the 15mph wind that it’s brought with it. I think the weather’s gone crazy. There didn’t seem much point trying to fly today. It might only be 26 degrees, but it’s still hot, humid and too windy to fly anything light. I really must make myself that 5 metre thermal soarer. And here I am messing about with indoor autogyros.

 

Seriously, though, I’ve got a lot of work to do fixing quadcopters for our next workshop. I was going to do the soldering yesterday, but it was much too hot. Today hasn’t seemed any better, so I’m waiting for the heat to ebb away before embarking on anything hot. You can see all the flight controllers in the picture that I need to test and then re-solder any wires back where the kids have ripped them off or shredded them. There’s also the dragonfly quadcopter that I need to finish designing and get flying. Unfortunately, this has taken a lot longer than I anticipated, mainly due to my total ineptitude with CAD. Only when I held it up to a Hubsan X4 did I realise that it’s actually the wrong size! I’m not sure how that happened, but it needs to be made bigger and some method devised to attach the flight controller and battery.

Finally, I’ve been putting the videos together of the autogyro build. Again, this took longer than anticipated as I’ve been at it all week. I’m going to try and do some flying shots as I’ve been testing it on a control line, but it’s all very cobbled together. I’ve just removed a HubSan video board which weighs about 4g so that I can film what’s happening as it’s whizzing around in a circle. I’ve been playing around with the balance and angles for a couple of weeks and I think I’ve finally got the sweet spot.

Anyway, no flying this week, but potentially a build video to come later.

Lots of Wildlife

I saw swallows, skylarks, deer and the lesser spotted idiot with a Mavic today. The weather wasn’t great and steadily deteriorated as the morning went on, but I did actually get some flying in.

RS352 and deer. The deer kept getting scared by the tourists and coming over to me for safety.

There was a guy with a Mavic there when I arrived. I said hello to him, but he never replied. Then he tried landing his Mavic with lots of forward speed and managed to fold the prop arms in when it contacted the ground. Undaunted by this, he unfolded the arms, switched batteries and flew again. I would have checked the props first as the bang bang bang against the casing when the arms folded in on landing must have damaged them. What do I know though? He got away with it and wandered off without saying a word. After that I was on my own for most of the morning until another guy turned up with an Inspire. He avoided me completely and set himself up at the extreme end of the field. I’m not sure he really knew what he was doing as he spent ages getting it to work, even going through the full calibration sequence before finally getting it in the air and then not wanting to go too far from himself.

Same deer, same RS352, more iconic angle.

As for me, I got in four flights with the RS352, but I really am getting rusty. I need to fly more, or at least get a simulator to practise on when the weather is horrible. I’m thinking about resurrecting my own flight simulator software again and making it work. The genesis of this goes back to 1992, during which time it’s been C++, Java, Javascript and C#/Unity. It’s difficult being a professional software engineer and working on your own project at home, because the last thing you want to do when you get home from work is to sit down at another computer. However, this taught me how to fly in the first place, mainly because, in the course of making the software work, I ended up flying all sorts of virtual aircraft which had truly awful and potentially dangerous handling. I practised on some really difficult aircraft and then found it easier in real life. Then I ended up test flying other people’s planes, where this early experience with simulators had built into me the kind of intelligence and instant reactions that you need to keep things in the air that want make rapid contact with the ground. I’m very critical when I’m flying, which is why I finished today wondering why my RS352 was giving me a kick of roll every time I pulled up and round into a half loop. It didn’t do this before, but it seemed a bit out of sorts in the increasingly blustery conditions and I was definitely rusty. Now, if you pull up elevator hard and the plane rolls, then that’s probably a bent elevator. Left half and right half come up different amounts, causing the roll. In this case, though, I could pull up, go through the vertical and then only when inverted did it start to try to roll out to level. Something might not be quite straight on the aircraft, but I’ll give it another outing before attempting to make any changes. Like, I said earlier, the weather was doing strange things.

It’s the end of June, remember. This is not summer with a 13mph wind.

I did think it was going to rain at one point, but I got lucky. It only got very windy.

I’m aware I haven’t said anything about the mini autogyro that I’ve been building for a while. I have lots of build videos that I need to edit and I was doing some testing yesterday, but I need some radio gear to make it fly and you can’t test glide an autogyro. Despite this, I did give it a go to determine the balance and got a lot of useful data about rotor angles to airflow, hang angle and tail offset. I still need to put all the videos together into a final edit, but this should be done soon. Test flying is going to take a bit longer, but I’m wondering whether I should modify the design to include some conventional stub wings? You see, as the dual rotors spin down, they slow at different rates due to friction, which results in a right hand spiral dive. It might need some additional aerodynamic lift at slow speeds to make it fly in a more predictable fashion. Just a thought, but it’s still a work in progress.

Windy and Raining, Windy and Sunny

 

We have both types of weather today, but each comes with 40mph winds. It’s not a day for flying outside, with the strong winds and blustery conditions bringing sudden, heavy, downpours of rain.

I’ve been messing around building things and working out how to attach a motor and wheels to my small autogyro. You can see the progress so far in the above pictures, alongside my Atom autogyro to provide some scale. It’s balanced with a small 8.5mm drone motor taped to the front, which allows me to try out some test glides. I’ve moved the rotor attachment back to get the balance right, but I’ll wait until I have some radio gear installed before I finalise the position. For now, it just slides forwards and backwards to get the hang angle and balance right. The whole thing is a fair bit heavier than I would like, but it is designed as a test rig. All up weight is 27g, but it only needs a LiPo , Rx and two 1g servos added to fly (maybe wheels too?). Autogyros won’t glide, unless you count a slow descent to the ground and I don’t have something the size of Nelson’s column to drop it from. I’ve toyed with the idea of a wind tunnel made from a ducted fan, or even flying it via control line, but I need to get a motor and speed control in first. I’ve got some micro gearbox bits lying around, so I’m going to see if I can get it motorised and then take the testing from there.

Who knows, maybe next week the weather will finally relent?

Weather on the Edge

That’s weather on the edge of flyable. I don’t mind too much if it’s a clear-cut decision, but today was a bit marginal. Yesterday we had 40mph winds and there was a bit left over for this morning. With a forecast that it was going to get worse after lunch, I didn’t think flying was a good idea. I was also reminded of the weather last week, when I rather misjudged the wind speed. I’m still laughing at the thought of my trying to land going backwards towards myself. It’s a good trick if you can do it, but that particular one can wait until another stupidly windy day.

 

So, I thought, let’s stick the mini-autogyro rotors that I made last night out of the window and see how windy it really is. You get some really weird effects if you try to photograph a moving rotor. In the photo above you can see how the rotors are curved by the progressive scan of the sensor in the camera, showing fast movement in the scene as the frame is captured. You can also see that they’re moving in opposite directions because the distortion is mirrored. The left rotor is spinning anti-clockwise as you look at the image, while the right spins clockwise. Trying to take this picture, I was looking at the camera and wondering when the wind was going to pick up to make both the rotors spin. Then I looked at the rotors and realised that they were. The camera can stop the motion entirely if the motion is slow enough.

These rotors and mount are part of the autogyro build project that I’ve been filming over the last couple of weeks and I’m hoping to be at the testing phase by this evening. It’s the filming of it that’s taking so long, but, until I put all the video together, I have no idea whether it’s going to work or not. As for the autogyro, I think it should work, but these rotors are rubbish and I might have to make some more. The idea I had is to build a wind tunnel and do some testing inside first just to get all the angles right. It’s only 60g, so that’s perfectly possible. I’m now really looking forward to flying a second autogyro, one which I’ve designed and built myself, as it’s very exciting seeing your own designs take to the sky for the first time.

That’s about it, except that I’ve fixed my RS352 undercarriage from last week. After taking it all apart, it wasn’t actually that bad, apart from a manufacturing defect in the carbon fibre laminations. It’s been like this from new, but there’s a gap between the layers of cloth on the right hand leg. Quite a big gap, actually, which is now filled in with some additional epoxy resin. They must have not have had the mould pressed together properly when they made it, because there’s also a problem down at the bottom bend where the wheel attaches. Again, the laminations have a big gap between them, so that might also need some attention soon.

OK, well, I’m off to do some soldering on some micro drone motors to repair all our kit for another drone workshop in six weeks time. And of course, finish building my mini autogyro.

My Undercarriage is Broken

 

Yes, I got some flying in this morning! It’s been a month since the RS352 last flew, but it was stupidly windy. Sunny and hot, though, but with 15 to 20 mph winds that made my fourth flight of the day rather eventful.

There were already two people there when I arrived this morning. One was a beginner with a HobbyZone Apprentice (Cessna-like high wing trainer with SAFE), while the other was an HLG competition flyer with an all carbon aircraft. They stayed for most of the morning, but there was also a DJI Inspire, Phantom and a couple of smaller drones, none of whom came over to say hello. My first task, as always, while my batteries were charging, was to do a litter pick. Today, though, the wind had spread the rubbish all over the place so we tidied up all the stuff that was blowing around and pushed it down into the bin.

It was a day of mishaps really. First, the HZ Apprentice crashed due to pilot error in the strong wind. It came to rest upside down, but with no damage. I was collecting a particularly annoying piece of litter at the time and saw it from close range. Not long after that, we could see one of the horse riders up near the woods slip off the side of her horse, which duly bolted and had to be caught by the other rider. Both her and the horse were fine. Then, the HLG glider suffered what would appear to be a complete radio failure and went nose first into the ground. Damage to the fuselage seemed to be around the nose and wing fixing points with the wing surviving undamaged as far as we could see. As for me, I seemed to get lucky as it really was too windy to fly a 450 gram profile model.

The landing on my first flight was rather hairy. I was doing a fairly standard steep and fast approach, right up to the point where the wind appeared to pick up the aircraft and throw it ten feet to the right. It was a bit of a heart stopping moment, but I got it down OK, if a bit heavy on the right wheel. This was when I discovered that there was a problem with my undercarriage. The landing obviously didn’t help, but I think the bend in the carbon U/C piece has been gradually weakening for some time. It needs to be re-inforced, so I’ll be buying some carbon cloth and disassembling it later today.

You can see that there’s something funny with the right leg here, as the wind tries to blow the aircraft from right to left.

On the close-up you can see the crease in the carbon near where it meets the double fibreglass boards (white horizontal mark on the black carbon near the top).

Flight four was a bit of an event too. Now, I’ve flown in windy conditions a lot, but part way through my final flight, the wind decided it was going to a different level. I’d love to have an anemometer to find out how strong the wind actually was, but I’ve never flown in anything like that before. I was two minutes from exhausting the LiPos and thinking that there’s no way I can get the aircraft back down in this. Basically, I pointed the aircraft into wind and it struggled to penetrate, so I ended up flying backwards. I backed the power off and let it come backwards towards myself, thinking that this is how I’m going to land if the wind doesn’t let up. It was far too strong to attempt a circuit as I would have been blown too far downwind as soon as I presented the slab sided profile of the RS352 directly into the wind direction. Anyway, I did a few of these test “landings” just to get the hand of it, allowing it to come backwards and down until it was 10 feet high directly in front of me, whereby I would put the power on and crawl forwards and upwards to begin the “reverse landing approach” again. However, I got lucky and there was a lull in the wind at a very opportune moment, so I did a quick circuit into a more normal landing position and brought it in fast. Possibly a bit harder on the right leg than I would have liked, but, in these conditions, down is down. It has made me think, though, that maybe most of my landings have been more on the right leg than the left due to the way the aircraft often “crabs” in to land. I’ll have a closer look at this once it’s all fixed again, but it’s possible I might not have it trimmed very well.

Anyway, the only other thing that happened was a visit by a Chinook.

 

They talk about drones being a hazard to flight safety, but this guy has some heavy metal under his control and flew directly across the flight path of an A380 on final approach. It’s difficult to gauge how close they were, but with planes landing with only 30s separation, this must have given the pilot of the passenger jet a bit of a wake-up call. There’s no doubt that the helicopter went across and under him, then crossed the flight path again to go back off in the other direction.