Author: rwmilton

Autogyrotations

I flew the autogyro again today for the first time since its crash in October. It didn’t go so well.

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These are the before shots. I actually liked the previous all blue colour scheme better, but this one looks more like the RCM&E review model in its red, white and blue.

I was a bit worried that there wasn’t enough wind to turn the rotors for a hand launch, but there was plenty to get up to flying speed. The problem stemmed from the launch, as I’ve damaged my right shoulder and had to hand launch left handed for the first time. Looking at the launch video, it’s not so much a left handed problem as a consciously not throwing it forward too fast problem. The YouTube clips I’ve seen of autogyro hand launches show a gentle push with the arm at 45 degrees tilting the rotor disk to get it to spin up, followed by a slow transition from 45 degrees to level with the horizon and a push forwards. I was worried that my previous launches were more javelin style aircraft launches, in other words, get as much forward speed as possible. This isn’t necessary with an autogyro, as the speed is in the rotor disk. You do have to throw it flat and with some forward speed, which I didn’t do well enough.

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This is a fraction of a second after launch. This isn’t going to end well.

So, a fraction of a second after launch, I had an autogyro prop hanging in a vertical manoeuvre. All I could really do was try and stabilise it laterally, allow it to climb as much as possible and try to flip it around in a stall turn. Another five feet and I would have done it, but it ended with a fairly soft impact directly on the nose.

Spy satellite pictures show more of the descent back to Earth:

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OK, so I had a RunCam filming the hand launch and the images above are from a GoPro Hero 4 Session dug into the grass pointing skywards to the left. I wish I had captured more of the short flight, as you can see what I mean by “stabilisation problems”. I’m not just prop hanging, the head is pointing ground-wards at an alarming angle.

 

The damage isn’t too bad considering. Like I said earlier, I had it stabilised by the point of impact, I just needed more height to fly. It’s snapped the motor shaft, split the fuselage where the LiPo moved forwards and snapped the two spruce tail sticks. I am determined to fix this quickly and get it back in the air next week.

This is the most difficult damage to fix, as it’s right up at the point where the spruce longeron meets the fuselage. I’ll have to have a think about this.

 

 

The split fuselage is easy to fix:

 

Oh, and I nearly forgot, Pete the Pilot isn’t feeling too well:

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It must have been that negative g manoeuvre that I pulled.

So, that was the autogyro. I also had three flights with the RS352. There was one other guy with a high wing foam aircraft practising his touch and goes, the lady with the drones and a couple of guys with some really cool HLG gliders.

OK, where did I put that book on how to fix autogyros for the stupid and impatient?

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Stuck Indoors

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The roads are closed due to an event today, so I can’t get out to fly. I thought the weather forecast said that it was going to rain anyway, but it never materialised and it’s now hot and sunny again.

Never mind, I’ve spent the time filming a micro quadcopter build and setup with my new Taranis QX7S. The blue thing has just flown its first aircraft, although that was only the micro quad you can see in the picture and then only about 2 inches above the worktop to prove that it was working. The plan is to add the FPV and give it a proper go with the goggles later this evening.

The specifications are as follows:

4×8.5mm brushed motors

500mAh 25C LiPo

FrSky XM 1 gramme SBUS receiver

F3 EVO Brushed Flight Controller

CleanFlight Flight Controller Software

The FrSky bound to the XM receiver without any problems, but it was a real pain to get the auxiliary channels working for the arm and flight mode functions. You have to add a mix for the two switches and assign them to channels 5 and 6. The other thing to remember is to set the “Brushed” mode for the flight controller. This used to be something you had to set on the command line with “set motor_pwm_rate=32000”, but it’s now on a drop down option on the menu. With the receiver type set to “SBUS”, the flight controller should talk to the radio without any problems. NOTE: I’m using the FrSky LBT (Listen before talk) European firmware, which was pre-flashed in both the transmitter and receiver module at the factory.

Well, that’s it for now. I’m going to give the quadcopter a go indoors later, so we’ll have to see how that turns out. Hopefully normal flying will be resumed again next week.

Bank Holiday Flying

The weather is perfect this bank holiday weekend. It’s 26 degrees in the Sun with no wind. In fact, I was expecting so little wind that I didn’t bother with the autogyro as I didn’t think there was enough to spin the rotors and allow me to do the hand launch trick. It turned out that wind is the one thing you can rely on in this country, as it was a touch more turbulent than the flat calm predicted.

It was just me and my friend with a big thermal glider first thing. We watched a red kite soaring around effortlessly above us and listened for little skylarks calling to each other and doing their characteristic death dive down in to the long grass. After that a lot of drones turned up and it was chaos. Before that, though, there was a new guy with a small foam (<1 metre) thermal soarer type of aircraft. It was one of the cheaper ones as the TX had no rates and we couldn’t turn down the elevator as much as it needed. Being this small, it was more agile than he wanted as a beginner, so he went through a sequence of launching, climbing away, turning the motor off, flying, dropping a wing, panicking not knowing what to do and then hitting the ground quite softly. The front was glued and taped back together when required and off he went again. Possibly I should have flown it for him, but the nose was a bit of a wreck and it looked a handful. His persistence and slow improvement was something to watch as he really wanted to be able to do it for himself. His friend had a drone, which seemed to know how to fly all on its own. This was an F450 with a big black box of electronics that kept it airborne. After that we had two kids with 250 sized FPV drones, an Inspire, the usual guy with his wife and a Mavic and then at the end the two guys with a collection of wings, high wing soarers and helicopter. In addition to this my friend on the bike came over with an aeroplane. I haven’t seen him for ages and he brought a very old high wing white foam cabin model on 27MHz. I think it was a Hobby Zone Mini Super CUB, as the wings were held on with bands and it had been in the garden for 3 years. We didn’t have enough bands, so taped the wings on with white tape and flew it anyway. I absolutely loved it. The only thing was the throttle, which sprung back to the centre position (zero), so all the throttle control was from the centre position to full forwards. Then, every time you let go, the throttle would spring back to zero. Despite this, it felt like I was flying an old fashioned balsa and tissue plane, even if it was foam. I ambled around the sky for a good 10 minutes before making an absolutely perfect landing, running along the wheels to a stop right in front of me.

In addition to the Cub, I got three (maybe four?) flights with the RS352. I can do a really good right spin now, but left spins don’t work nearly as well. In the course of flying, I nearly took out a model helicopter and one of the drones a couple of times. We really need to do something about this as the drones are invisible and have no awareness at all of where they are and who is around them. Also, we nearly got hit by a high wing model as it was being launched. The guy threw it and the model just dropped the right wing a bit and very slowly did a 180 degree turn back towards us, skimmed our heads as we ducked and crashed into the ground. We also had a drone nearly hit someone flying from a chair as the pilot flying FPV didn’t know where he was. Apart from that I got some really good flying in and really loved the opportunity to fly the old fashioned cub.

Finally, another friend turned up just as I was leaving with a brand new foam Corsair. He hadn’t flown it yet and was obviously nervous, but this was the same type as I flew for another guy about a year ago. As I said to him, with the AS3X technology, anybody could fly a warbird and this one was an absolute dream to fly. I saw him with it in the air as I was on my way home, so it went up OK.

That’s all for this week, sorry there are no pictures, but I forgot to take any with all the stuff that was going on. I’m on an enforced rest next week, but might have some interesting news to tell.

Canada Downtime

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Grid Drones

I’ve only just got back from Canada after attending the CHI2018 conference, so I really needed to do nothing for a bit this week. The weather was quite bad anyway, so it wasn’t much of an opportunity missed. It’s been a very grey morning, cold, with more wind than they forecast and light drizzle while we wait for the heavier rain to arrive in the afternoon.

Anyway, while I was at CHI I got to see a drone demo which was interesting. I had a chat with the guys while they were setting up and their drones are about 60g with a square frame comprised of carbon fibre cross pieces. They use very thin carbon strips of about 0.5mm thickness and about 5mm wide, but end on. The six sides of the cube have a carbon cross in them so that you are looking at the 0.5mm face and the 5mm depth makes it strong if you push on the side. And that’s exactly what they got a little kid to do. They put him inside the net and let him move the drones up and down and around, which is what they’re designed to do. They are based on the 100mm brushed motor type drone with 8.5mm motors and 55mm props, so they’re not dangerous. Added to that, there is the carbon cube frame, so you can’t put your fingers into the props very easily. The individual drones are position tracked, using the infra-red emitters you can see at the back of the picture (red circles on tripods). This means that they stay in place and adjust up and down to make a surface as you move them up and down. It was all very impressive, so now I’m left wondering whether I can make something like a drone turtle for national robotics week in July? I would like to make something that the kids can program and see move around a path that they can set. I’m off to have a play with some microcontrollers now.

A Grey Day with Clouds Brewing

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My Atom autogyro modelled in Blender (work in progress)

The weather didn’t look good this week, so I had decided not to take the autogyro out. It was just that it was very changeable throughout the whole morning, with strong winds, then calm, but always with lots of threatening dark clouds overhead and occasional sunshine peaking through.

When I arrived, I bumped into a guy with a drone on his way home. After that another guy turned up with a Phantom, then the lady with the custom drones, a couple with a DJI Spark (selfie copter) and another Phantom. I had the only fixed wing of the day in my RS352. However, another guy came over on a bike and, after chatting for a while, he said that he was definitely going to bring his aircraft over one Sunday morning to learn. That’s a good result.

Anyway, I had 4 flights with my RS352. My flying was really erratic this morning. I think I must be getting out of practice. I managed some good landings in the blustery conditions, though. Although I didn’t take the autogyro, I have been slowly building a virtual 3D model which I can put into my simulator. That’s the image at the top of the page this week, but it’s still very much a work in progress as I’m not very good at 3D modelling. The only outdoor photos I took this week were a set of selfies of me and the RS352 with the clouds in the background, but I’m not going to inflict them on anybody. They didn’t come out very good.

That’s it for this week, but I’m on an enforced break next week due to being out of the country, so the next flying is in two weeks time.

My Autogyro is Flight Ready

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And there he is in all his autorotating readiness. I’ve finally finished repairing my Atom Autogyro after only 6 months and it’s now ready to fly again. Except for the fact that the weather isn’t playing nicely. We’ve had heavy rain earlier in the morning and then that sort of light misty almost not there rain that soaks into everything.

Oh, well, that gives me more time to check out all the autogyro’s systems to make sure everything is working perfectly.

 

OK, that’s quite a lot of autogyro pictures, but I’m rather pleased with the results. I can’t wait to fly it now.

Talking about flying, now that I’ve got it all back together again, I’ve been wondering how the propeller managed to shear the blade off in fight the last time.

 

The pictures above show the full forward, centre and full back positions, as near to side on with the propeller vertical and the blade in the directly forward position as I could manage it. By my measurements, even in the full forward position, the blade has to bend down by 13cm in order to hit the prop. The dimensions of the blade and position of the strike just about work, if the first contact came with the prop about 45 degrees on the right side of vertical. There’s what looks like an initial hit on the leading edge of the rotor blade, then the whole thing has sheared off about 2.5cm inwards, so it’s entirely possible that there were two contact points on successive rotations. I’ll never know for sure, but I’m now going to look further into how much the rotor needs to tilt forwards. I think autogyros generally need to keep the rotors in the back position and never forwards of the horizontal, but that’s something I can research during the week.

Let’s hope next week brings some good autogyro weather.

Easter Fools

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It’s Easter Sunday today, in addition to being April Fool’s Day. The weather forecast for the days I’m not working during the Easter weekend went something like this: rain, rain, rain, overcast, rain, snow, rain. Today was the overcast one, so we all trusted the forecast and had a go at some flying.

When I arrived at the field this morning, there was my friend from last week with a 3.8 metre Explorer electric F3J glider. This is a serious bit of kit, weighed almost nothing and could make three flights totalling over an hour on a single 1350mAh LiPo. For comparison, I had three flights this morning, of 7 minutes each, giving me just 21 minutes of flight time. The Explorer looked so at home in the sky, it’s just such an elegant thing to watch effortlessly defying gravity. In contrast, I should have got more air time this morning, apart from the fact that my LiPos weren’t charging properly. There’s a problem with the balance lead connectors which was causing the battery voltage to not be read correctly, and it kept aborting the charge until I fiddled with the wires. Either that, or they just didn’t like the cold weather, because it felt like it was freezing when I was flying. I just couldn’t get warm today and shivered my way through all my flights.

In addition to us two, the lady with the micro drones arrived towards the end of the morning, along with another guy and his girlfriend who had a UMX sized Extra 300, a Falcon helicopter and a small drone. The Extra went really well and looked a lot of fun. I’m sure I’ve seen one of these before, but I can’t remember who the manufacturer is. It might be one of these, though: [nitro planes link].

Along with us, there were also a few drones around. The first was a guy we noticed flying out towards the road, then another in the direction of the rugby field who had what looked like a racing drone that was absolutely lethal. We were at quite a distance, but he obviously didn’t know how to fly it. At one point the group of four looked like they ducked as it was hovering in front of them and then raced over the top. They were still there when I left, so I picked a safe route back across the field.

One thing I did notice this week was that the stream has got water in it again after being dry for so long. There was a huge torrent of water running down and into the drain, which I haven’t seen for quite a few years now. The huge amount of rain that we’ve had over the last few days made it quite boggy this morning.

Finally, watch this space as I should be autogyro-ing again very soon. The picture above shows the almost complete state of my Atom Autogyro. All I really need to do now is to balance the blades. I had a bit of a problem here as, although there were originally four blades that I made up, I picked the closest matched three to use. This meant that my fourth, backup, blade was a bit heavier. Now, I couldn’t weigh the other two and remove some excess weight from the third because the other two are covered. All I could do was to estimate what the weight of the new blade would be once it was covered. Well, I covered it yesterday and it’s 1.0 grammes heavier. My three blades weigh 26.0g, 26.5g and 27.0g. That’s not a bad result from my guess, but they don’t balance. I’m going to need to add more than just tape as I need a gramme of weight to balance them. It took 12 pieces of tape, which I then weighed and substituted with small pieces of lead shot. What I’m going to do is to slice the two light blades with a knife, insert the lead inside and seal it up so it can’t get back out. Given how fast these blades spin, I’m a bit paranoid about things flying off from the blade tips.

That’s all for this week, I’m now off to do the final blade balancing on the autogyro.

Cloudy, with a chance of Drones

It was a dreary, overcast morning today, but eminently flyable. I bumped into an old friend who I haven’t seen for ages. He was flying a Heron motor glider, at least he was up until the point where the right flap servo stripped in flight. All was OK, but it put an end to his flying for the day.

There were lots of people around when I arrived. An Inspire was hovering away in one corner, another drone was a little further away. The lady with the micro drones arrived later in the morning, and another guy had a drone and a blue high wing Cessna type aircraft (more like an Aeronca?). There was also somebody with an array of flying wings with FPV and a big twin boom foam aircraft which he was running iNav on for the first time.

Early on, we also had a young boy turn up with his parents and sister. I don’t think he could have been more than about 10 years old and he had a brand new, unflown, Ares trainer. I think it was a Gamma Pro 2, but I’m not sure. Anyway, we helped them out with it as the controls were a bit stiff, there really wasn’t much elevator movement and the battery was free to move around inside. After sorting out the elevator and stuffing the battery with tissue, the balance was fine, all the controls worked fine, so there were no excuses left. The thing that makes me nervous with this type of aircraft is the automatic control system. Personally, I would do the first flight on manual, trim it and then let the beginner loose with the computer backup system. It even has a panic button on the top left of the controller in case they need it. However, it’s always a bit of a risk flying a new aircraft and I was mindful that the boy wanted to fly it, so I launched and he had the transmitter. The launch was fine, it just needed a touch of up elevator from him to fly away, but he ripped the undercarriage off on the ground before it escaped terra firma. It flew around quite impressively, though, and I never touched the controls once. He landed OK, then we had another go at launching, this time without the undercarriage. It got away without incident this time and he was flying around quite happily while I was standing next to him watching and talking to his mum. He seemed to be getting the hang of it, but really wasn’t concentrating on what he was doing very much. I’m annoyed as I should have been paying more attention, but his mum distracted me and he managed to fly it into the ground. I saw him do it before it happened, but there was no way I could prevent it. The damage wasn’t too bad, but the wings had parted company at the centre join were the spar locks the two halves together and the tail had snapped off. Looking at the huge strake on the fin, though, you could easily glue it back together and use that as a strengthener. The wings were also easily fixable, so, hopefully, we’ll see them back soon. I did offer him a go of my RS352, but he really didn’t want to. I might be wrong, but I think his mum might be more interested in flying planes than he is.

Because of the clocks going forward this morning, I lost some of my flying time, so I only got two flights with the RS352. They were a good two flights, though, as the plane was feeling very aerobatic. Obviously, it hadn’t flown much this year because of the weather, so it was making the most of the zero wind conditions, even if it was grey and murky and looking like it could rain any minute.

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Finally, I have a new solarfilm iron, so I can finish off the autogyro repairs. As you can see from the pictures, it’s now got the film on the nose and fin, plus some white lines to hide the join. All I need to do now is to cover the blade and balance it.

 

I was very surprised at how different it was using the new iron compared to my old one. You obviously need to learn where to put the temperature dial, but the new one has a much more slippery shoe and the temperatures for the profilm I’m using are all in the top range of the dial. The quality of my covering on the blue nose is appalling, which is strange when you think that I’ve been covering aircraft like this for the last 30 years. I just liked my old iron.

One last thing, but the solarfilm iron wasn’t the only new thing I bought this week. I’ve also got a new Taranis QX7S which I’m going to use for the quadcopters and indoor flying.

 

Snow Butterflies

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It’s the impression left by the dragonfly quadcopter in the fresh snow.

We had several centimetres of snow overnight and the strong easterly wind is making for a wind chill of about minus 3. I’m quite happy to have a rest indoors this weekend, though, as I’ve just got back from showing the quadcopter flight simulator at this year’s Big Bang Fair.

 

At this point, I’m quite happy not to go outside in the sub-zero conditions and have a well deserved break instead. I’ve been having a go at filming the Leap Motion controlled drone simulator which counts as having a rest for me. You might see the results on YouTube soon.