atom

Life and Brian

We’ve got the tail end of a Winter storm called Brian this weekend, which has brought with it winds of 50 mph, so flying isn’t possible. I’ve been fixing my ATOM autogyro this week and looking at the video footage from last week’s crash.

Atom away! This is from the video of last week’s launch before things went wrong 26 seconds later. I’m not sure what’s happened with the white spots on the image, but they were both fine before I transferred the images to a Linux machine to upload to the blog.

These rather blurred images are blown up frames from the video as it wasn’t much more than a dot on the screen when the rotor failed. The image on the left shows it flying left to right normally. You can just about make out the tail (bottom left dark blur), fuselage (bottom right) and rotor (top). The image on the right is just after the point of failure when the rotor blades folded up. It’s still moving left to right, but has now pitched up about 45 degrees. The lowest point on the image is the tail (8 o’clock position), with the boom and fuselage visible, then the mast pointing up at 11 o’clock. It just fell to earth from there.

Now that I’ve had a chance to examine the wreckage in more detail, I would say that I was quite lucky with the impact. All it’s actually done is to snap off the nose, break the two booms and do some other superficial damage.

 

Looking at the bits, I think the point of impact was on the right hand side of the nose. That’s with the fuselage rolled 90 degrees right when the ground jumped up and prevented it falling any further. Neither the prop, motor nor undercarriage are damaged, ruling out a direct nose in impact and a wheels hitting first impact. The right side of the fuselage nose seems to have taken the most force and judging from the way it broke, I can see how it snapped. The LiPo exited via the left side of the nose and you can see the evidence of where this happened. I’m assuming that the tail then followed the broken nose into the ground, splitting the spruce 6mm square longerons, but doing very little damage to the fins.

Now, on to the repair and I had already set and glued the spruce tail sticks back together during the week. I used epoxy resin, fitting the split ends back together quite easily and binding them with tape and G clamps in a frame I rigged up to ensure I got everything square. The tape allows me to get some force on the wood to pull it back into shape to then put the clamps on without sticking everything up with glue. Once the glue has set, it can be removed as the epoxy won’t stick to it.

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After that I set about the fragmented nose section. In the end I decided to graft a new 6mm base section on the existing fuselage, along with some new front side sections. The ply firewall is unrecoverable, so I made a new one, but was able to salvage the ply plate for the undercarriage and the internal ply plate. The front section of the nose is a sandwich of multiple sections, which makes for a very strong construction, but complicates the process of repair. I traced the drawings off of the original plan, cut them out and used them as templates for the new pieces.

 

That’s my new base and ply firewall ready to be glued in place. Now all I need are the fuselage side pieces to graft in. I do find repairing aircraft a very satisfying experience.

That’s all for now, more to follow later.

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Autogyro Flies!

After starting the build in Autumn 2014, I can finally say that I’ve fulfilled my ambition to fly my own autogyro. It didn’t all go completely to plan, though.

Last night I added a bit of extra shim to the blades to help with the spin up:

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LiPos charged, I was ready for the first flight of the day, so, here we go again…

 

I decided to use the wind to spin up the rotors and then hand launch, which worked last week when I got my first 10 second flight. This week it was a bit windier at around 8mph, which I figured was perfect. This time I had the trims zeroed, so the head head was at 90 degrees to the mast, which is the recommended position. I tipped the aircraft back so that the nose was vertical, the blades spun up to a speed where there was a definite “lifting noise” from them, increased the throttle and rotated to the horizontal launch position and released the aircraft into the air. Immediately it wanted to go backwards and I spent most of the 20 second flight with the elevator stick all the way forwards trying to control it. Anyway, the landing wasn’t too bad, in long grass over to my left and downwind. On recovering and checking the aircraft, I discovered that the right fin had snapped in the landing.

 

I borrowed some cyano and patched it up with sellotape, then I moved the elevator trim all the way forwards and gave it another launch. I had a four minute flight with it this time, flying backwards and forwards in front of myself, demonstrating some semblance of control.  This time I was actually flying it, even if it was a bit of a handful to start off with. The thing is, it was pulling badly to the right, so I spent the first few minutes gently dabbing in a couple of clicks of left aileron trim until it was flying more comfortably. That’s 25 clicks of left and about the same on the down elevator prior to flight, which explains my earlier comment of, “a bit of a handful”. Especially when you’ve never flown an autogyro before, and it is a very odd thing to fly. Also going through my mind was the fact that the fin was held on with sellotape. That’s why I was very reluctant to use the rudder, but I did  give it a go near the end of the flight.

As for the flying, the elevator controls the speed, while the throttle controls the height. I did actually get up quite high at one point, but I was very careful not to let it get too far away from me as the orientation is a problem. I had a couple of moments when it was turning towards me and I lost orientation. What really surprised me was how much height I was losing on the turns. I was flying off to my left, turning 180 degrees, losing half my height, then picking the height back up again as I flew in front of myself, only to lose it again on the turn at the right hand side of the box I was flying in. It didn’t seem to matter if I turned left or right, the height loss was the same, and there were a few points where I couldn’t turn tight enough to fly in front and had to do a big circular circuit around my head. There didn’t seem to be much authority in the turns, but I can live with slow and docile at this point. Like I said before, I did very gingerly try the rudder out at one point and it was effective in bringing the nose around, but I was too scared of the cyano and tape on the fin giving way to do very much. Anyway, that was the battery exhausted, so I had to think about landing. This proved to be very easy and I touched down with almost zero speed and so lightly I’m sure my pilot in the red baseball cap never even realised. The only thing to mention here is that it’s very important not to reduce the speed too much. I was on the point of doing this and could feel it rolling left as the speed was decreasing. Post flight analysis of the battery showed that it only had 10% left.

Four minutes of autogyro flight! I’m only saying that again because it goes a bit downhill after that. On the next flight, the launch was fine, but it just didn’t seem to have any power. I can’t understand it because I did two launches, and both times it didn’t want to climb, landing about 20 seconds later. On both occasions, there was ample power when the aircraft was recovered. I decided to charge up one of the new 1300mAh packs and see what difference that made, but I’m fairly sure I made a mistake launching. There wasn’t enough speed in the rotor when I released it, the aircraft went away, but climbed too fast and rolled to the left. It was like it did a stall turn from my hand and I almost managed to recover it, but it hit the grass quite hard on the two wheels and tail skid simultaneously. This had the effect of partially splitting one of the spruce longerons and put paid to any more flying.

 

I always suspected that a hard landing would cause a break like this, but it’s easily fixed with some glue and a couple of plywood doublers. In my defence, I think the rotors were spinning at the right speed, right up until the point where it left my hand. The wind dropped at just the wrong moment, causing the rotor speed to drop as I brought the aircraft up to the horizontal and applied throttle.

Anyway, I’m very happy now that I’ve achieved my lifelong ambition to fly an autogyro, so I’ll fix it up and have another go soon. Oh, and by the way, there should be video of the event, assuming the camera worked. I haven’t had time to look yet. Post-flight analysis of the flights were there was no power could be interesting. I’m wondering whether I was pulling back on the elevator more than I realised, rather than giving it throttle? I really don’t know, as I definitely had 100% throttle and had to back off to land. Would forward tilt have increased the speed and built up lift? What I would really like is some sort of telemetry to record my transmitter inputs along with the flight video.

As for the rest of the day, I had a single flight of my RS352 right after the final flight with the autogyro. I buzzed around the sky with an old Corsair, which was a lot of fun. We were dogfighting with each other, but pretending that we weren’t. Him and his father between them had a fair few aircraft, including a Lazy Bee and a UMX Beast, which I’ve flown before and which he threw around the sky very convincingly. There was another guy who helped me with the autogyro last week, but this time he had brought his son and was teaching him to fly with a buddy box. I haven’t seen that for a long time, but together they were flying a Bixler. I also discovered that the aircraft I maidened last week wasn’t a Bixler, but actually a SkySurfer. The same guy was here again this week, but with his Nieuport biplane this time. Unfortunately, the Nieuport had a bit of an incident on its first take-off, then got into the air, completely out of trim, gradually settled down into flying, but suffered another incident on its second flight. This time it looked like the top wing was damaged, so he went back to his car and brought back a contra-rotating helicopter. This also flew, but it looked like the wind wasn’t its thing. When I had to leave at the end of the session, I left him with my sellotape fixing something on it. We also had a lady with a micro drone, brushless, and made from carbon fibre. I think I last saw her on the autogyro’s first outing a few weeks ago, but a couple of her friends also turned up with drones. There were also another couple of drones at the opposite ends of the field not wanting to talk to us (I wonder what they made of an autogyro flying past?). Finally, the guy with the Bixler also had an own design, small, agile, high wing plane that he spent the best part of a decade building. He asked me to have a fly of it and see what I thought. Well, it’s actually very nice to fly. I thought it was going to be very sensitive to roll, but actually, the controls were very well balanced. It was fast, agile and aerobatic, without being overly so. Anyway, he’s got a SIG Cobra pattern ship type plane that he’s just finished and wants to fly next week.

That’s about all there is for this week, except that I’ve still got the video of the autogyro flight to have a look at and edit, plus some repair work to do. I’m still determined to make the autogyro a regular flier.

First Flight: The Autogyro Flies

 

I flew the autogyro! I don’t care about anything else at the moment, I finally flew my own autogyro. As an added bonus, I also managed to catch the flight on my RunCam. I honestly thought I was gyronauting for at least 30 seconds, but the video says it was only 10. It must be down to the number of control inputs I was having to put in, because this was one first flight which didn’t exactly go to plan. To begin at the beginning, I put bigger wheels on the Atom to increase my ground clearance and hopefully help the ground run build up rotor head speed. You can see the big foam tyres in the pictures. I must have spent the best part of an hour running along the ground with it doing exactly the same thing every time. There’s lots of video of that too so I can analyse it later. The aircraft runs straight initially, then veers off to the left as soon as the head gets to a certain speed. I tried altering the head angle (aileron) and rudder to counteract this, but to no avail. If I did get up enough ground speed for the head to spin fast enough to lift, then what would happen is that the right wheel and tail would lift, but the left wheel refused to unstick. I got very proficient at careering along the ground on just the left wheel and dragging the left fin, before crashing into the grass at the left edge of the runway. I just couldn’t get it to track straight and really need a fatter section of flat grass to take off from. The wind wasn’t helping either, because it was very thermic and the wind was from all directions during the morning, but never much more than about 5mph.

To cut a long story short, I hand launched it. One of the guys flying DLG had come over and suggested hand launching, but I was very reluctant, unless I could see the rotor spinning up to speed first. This is where I now owe the weather a favour. While I was discussing the YouTube video I had seen on how to hand launch an autogyro, the wind picked up, the rotor spun up to speed and I just looked at him and said, “that’s it”. With the autogyro’s nose pointing vertical, the rotors were spinning furiously in the wind, I did a control check, rotated it smoothly to horizontal and pushed it forwards. It flew. Well, I say it flew, for the next 10 seconds I had the sticks in all four corners in order to avert was was increasingly looking like a crash. I think my helicopter flying skills kicked in at this point, because that’s what I was doing, watching the rotor head, keeping away from the ground and trying to stay flat and nose down. Needless to say, the head was too far back and it was flying on a stall. Everybody thought it was going to crash, but I’m able to walk away with 10 seconds of autogyro flight, an undamaged aircraft and a lot more knowledge about autogyros. I can’t wait for next time.

Autogyros aside, it was a very eventful morning for other reasons, not least of which because the weather was perfect and there were more people and aircraft than I’ve seen in a long time. There were already three guys flying DLG exceptionally well when I arrived and another with an own design trainer using the path as a runway. Then the guy from last week arrived with his F15, bringing along his daughter this time. I got to launch the F15 on its first flight. Somebody was flying a drone (noisily) over by the river. My first flight of the day actually came from the guy who brought a UMX Spacewalker over on his bike. The Atom was actually my second maiden flight of the day as another guy I see a lot had a brand new Bixler. I flew his Hurricane a few months back, and he was going to fly this himself, but then we got into, “I can stand next to you while you fly if you want… can you launch it for me… why don’t I just give you the transmitter and you fly it?”. So I flew it for him, which was probably a very good thing. I noticed on the ground that there wasn’t much aileron movement and it really did need more in the air. Luckily the rudder worked OK. I had to check the rate of ascent from the launch, as it wanted to go vertical, then it was rolling left badly, so ended up putting in lots of right aileron trim. I was fairly happy with it flying more or less level by this point, but it was sluggish and really wouldn’t turn right. I was holding in full right aileron and nothing was happening. I kept increasing right aileron trim, which did help, but it needed more movement. Landing was interesting, as I lined it up to run past in front of us, I realised I needed to correct to the right, nothing happened and I elected to add power to go directly over our heads and go round again. The landing on the next circuit was perfect. The owner then added more movement, I took it up again and handed it over to him. It flew perfectly after that and he had a few more flights on his own. I was really impressed at how well it would glide. Although I called it a “Bixler” earlier, it might have been one of the other clone versions, but basically, it was a Multiplex Easy Star type.

We had two more arrivals in the form of the guy who flew the Witch drone at Halloween last year, who was flying a Mavic. The other was a guy I’ve known for ages, who usually has a Stryker, but this time had a UMX A10. He broke something on the first launch and had to tape it back together, but his one and only flight after that was very impressive. The Mavic had a go at filming my adventures with the Atom, but I think the only footage he would have got was me crashing into the grass at the side of the runway. There were at least two other people flying drones by lunchtime as well, so there was so much activity this morning I couldn’t keep track.

After messing around with the Atom almost all morning, I also had two very quick flights with my RS352, swapping LiPos and going back up without even switching off the transmitter. The time on my transmitter display shows 50 minutes this morning, most of which was with the Atom. So, just to recap, the planes I’ve flown this morning are: UMX Spacewalker, Bixler (Maiden), Atom (Maiden) and RS352.

Anyway, I’ve got about an hour of autogyro video to analyse before my next flight.

 

Post Autogyro

The weather wasn’t very good this week, so I didn’t get to do any flying. The forecast was for heavy localised showers and, right on half past twelve, it rained. A lot. I might have got wet, or I might have got lucky, but, either way, it was just as windy as last week. If the weather had been calm, then I would definitely have had another go with the autogyro, but there didn’t seem much point with the weather like this.

I’ve been looking into the problems with the autogyro and come to a number of conclusions. Firstly, the video I captured was rubbish and didn’t tell me anything. If I try that again, then I’ll have to get the camera higher up. The next thing is that I don’t think I got the rotors up to flying speed as everything I’ve read says that there is a characteristic “whirring” when this happens. It’s supposed to take off at walking pace, which I achieved, but I think there might be something wrong with the rotor head. I went round all the factory fitted bolts and discovered that some of them were quite loose, which was causing a lot of play in the head. In addition to this, I’ve been reading the “Cruiser” autogyro build article from the November 2015 RCM&E, which is basically the same design as the earlier Atom. There is also the larger “Panther” autogyro article from the Model Flying Workshop Special, published in 2015, which contains all the original articles which were serialised in RCM&E from March 2013. These all contain basic instructions on the design of the head and how to test fly an autogyro. However, while they advocate short hops to ascertain the trim, I’ve seen a video on YouTube where an Atom was hand launched in almost gale force wind. This is something I’d never seen before, but you can apparently hand launch an autogyro very easily: https://www.youtube.com/watch?v=OdrfQxKu1Ik

This video is also interesting, as it suggests that the left wheel sticking to the ground is normal and that you can power on past it: https://www.youtube.com/watch?v=9OVpcZOvsOs

If the camera I was using had worked, then this is a carbon copy of my experience last week, except that I wasn’t brave enough to get it into the air. After some playing around on the ground, my feeling is that the left wheel coming up last is due to the anti-clockwise direction of the main rotor.

This is the other hand launch video of an Atom that I found: https://www.youtube.com/watch?v=5bVkgLwmBAc  I’m just not sure I’m that brave.

Anyway, I’ve checked the balance by measuring the hang angle using some rulers and a bit of trigonometry. By my calculations it’s 18.5 degrees, which is spot on. I’ve also modified the 0.8mm shims on the underside of the rotor mounts as they were getting caught every time the blades got tangled up last week. I’ve now lengthened them and covered over them, but I suspect that this might be where my problems lie. When I spin up the rotors on the ground, I just don’t feel like I’m getting much movement of the air. Now, the HK head has a known problem in that it’s constructed upside down and shipped in a state where the rotors would give no lift (souce: modelflying.co.uk Atom build thread). I took it apart as directed, fitted the fibreglass triangle to replace the plastic one which breaks and rebuilt it the other way up. I’ve added the shims as instructed, which put the blades at a more negative alpha and aid in spinning up the rotors. I’m not convinced that this is right, though, so I’m going to do some more investigating before I try and fly again.

That’s it for this week, but work is taking over again, so I’m not sure how much I’m going to be able to do on the autogyro. I’ve got this close to getting it in the air though, so I’m not going to give up now.

First Autogyro

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I was determined to test fly the Atom autogyro this weekend and I finally managed to get everything together. I don’t know whether this is the first autogyro that’s been flown at this site, but in all the years I’ve been flying here, I’ve never seen another one. I also don’t know whether this counts as a flight, because the left wheel never actually left the ground, but this was my first attempt.

My first flight of the morning was with somebody else’s UMX Champ. Weighing only about 35 grams, this was probably a stupid idea in the steadily increasing wind, but I’ve flown it perfectly well in windy conditions before. This time, though, a gust flipped it upside down and I crashed into the ground. I was able to partially rescue it, so there wasn’t much impact and it was undamaged.

Then I put the rotors onto the autogyro and had run out of excuses for not flying it. Although, it was a close call as the wind was way above the recommended “light winds” stated in the magazine article for the first test flight (RCM&E Autumn 2015 Special). I was determined to give it a go and try running it along the ground and “hopping” when the rotors began to lift. The rational behind this is to trim the head angle, but I didn’t have much luck. I had the foresight to take a GoPro Hero 4 Session camera with me and record the flights so I could watch them back later, but I had it in the wrong mode for the first set of flights and only ended up taking stills. I really don’t like that camera, but I had lent my preferred RunCam to somebody on Thursday.

As far as the test “hops” went, the rotor would spin up fairly easily in the wind, but I’m not convinced I was getting up to full flying speed before running out of runway (for “runway”, read “patchy bit of bumpy grass”). I wasn’t able to steer effectively with the rudder and it seemed to be yawing to the right. When it did start to lift off, the left wheel seemed stuck to the ground and it wanted to roll over onto its left side. I thought this might be a head trim angle problem, so I progressively added right aileron trim, up to the point where I had 15 clicks right trim and there seemed to be no difference, even when holding right aileron while it ran along the grass. The airframe is impressively resilient though. I had it tip over on its left side numerous times and tangled up the rotor blades, but it still went home in one piece. I think that, in all the years I’ve been flying, maybe I’ve learned how to crash well?

After resting the autogyro for a bit, we then had another go with the Champ. This time it went really well, much more like I would expect, so either the wind had eased off a bit, or it was just less turbulent than before? However, while I was flying the Champ, the Atom got blown over onto its side twice, tangling up the three rotor blades again. Luckily, there was no damage, but, with its three rotors now attached, the wind was causing them to spin very fast, resulting in it tipping over. I would have said that it was at flight speed at one point, they were spinning that quickly in the wind. Seeing this happening, I brought the Champ down for an almost perfect landing and rushed over to the Atom with the transmitter still in my hand to assist the owner of the Champ who was trying to figure out how to stop the blades. This confused him completely as he missed my landing and thought his aircraft was still in the sky. Anyway, still no damage to the Atom or Champ. The RS352 tried to take off on its own as well, but it’s fairly indestructible. I’m starting to think that maybe this wasn’t the best day to test fly an autogyro?

At this point a couple of guys arrived with a chair and a drone and proceeded to sit right where I had been doing the Atom test hops before. I’m not sure where they were from, but their English wasn’t great. There was also another drone flying right up the far end of the field, ignoring us completely. This was an East European couple and their son, as the lady did come over to us later on to borrow a screwdriver to change the battery in her son’s mini drone.

OK, so having had a think about the autogyro, and with the wind lessening a bit, I had another go. This time, though, I managed to get the camera in the right mode, so I’m hoping there should be some video there for me to review later. This went the same as before, trying various directions into wind and trying to get forward speed and rotor speed for flight. Along the ground it was yawing to the right if the rotors were spinning, but tracking more straight if the head didn’t spin. The ground handling wasn’t good enough to to keep it in a straight line along the runway I was now using, which was almost directly into wind, but narrow and with stubby grass either side. I kept ending up in the grass to the right. Moving to another area didn’t really help as the aircraft would never pull its left wheel off the ground. In the end I gave up, which was very disappointing. I would have taken any sort of air under the wheels, even millimetres. So, to review, rotor spinning means yawing right on the ground and left wheel won’t unstick despite extreme right tilt and good rotor speed. I need to go away and do some research for next time.

After that I had 3 flights with the RS352, which loved the conditions on its new batteries. I had one of the older batteries (3S 1100mAh, 18 months old) in the Autogyro, which showed 50% full when analysed after the test flights. The other one I flew in the RS352, but it just didn’t have the punch of the newer cells. As I had the GoPro set up anyway, I decided to point it at a patch of sky and film myself flying the RS352. I don’t know what footage I got yet, but maybe I got something good with the wide angle lens?

While I was flying the RS352, we had another person arrive with a drone who I’ve never see before. She also wasn’t like all the other drone flyers as she knew what an autogyro was, even if she didn’t know the English word for one. My guess is that she was East European from her accent, with bright red hair and a mini drone which she had constructed from bits herself. It was a bit bigger than a 100 size (but not by much) and had tiny brushless motors and FPV. Unfortunately, she had forgotten to charge the goggles, so couldn’t fly with FPV and didn’t feel confident enough to fly with line of sight because of the orientation. She apparently files bigger drones too, but she obviously knows what she was talking about as we were discussing why neither of us would do some of the stupid things the other guys were now doing with their DJI Phantom. After that a husband and wife also turned up with a Mavic, but I had to go at this point.

That was quite an eventful day of flying, so now I’ve got to go away and do my homework on autogyros.

Remembrance Sunday 2016

It’s Remembrance Sunday this week, so what we usually do is to put an aircraft up and wait until we hear the cannon. Not having a Spitfire or Hurricane (or Tempest), I had to resort to flying a Taylorcraft.

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The weather was perfect, with lots of sun, no wind and not at all cold. I had one flight with my RS352, then the Taylorcraft, followed by a Hobby King Bixler (EasyStar clone). The Bixler had an issue with its flaps not being connected to anything, causing them to flap around on their own. After the owner had flown it, he asked me to have a fly to see if I thought it was behaving oddly. Not surprisingly, the free flaps were causing it to fly in a rather erratic fashion. It was flyable, but you had to constantly correct it. Also, he didn’t tell me until afterwards, but he had the rudder trim and aileron trim on opposite sticks. I had been feeding in right aileron during the flight, which was actually right rudder. I can honestly say that I’ve never seen that type of setup before and can’t think why on earth you would do it. He said that the idea was to be able to trim it without taking your hands off the sticks, but it’s just confusing. I also did a dive test to determine the centre of gravity, which turned out to be round about neutral. It didn’t quite tuck under in the dive, but it sure wasn’t stable, so we suggested adding nose ballast until he’s comfortable with the flying characteristics. Thinking back, I did fly one of these a few months ago which was very tail heavy and was a real handful to fly. It must just be down to the kits. As for the flaps, I suggested he put the hinges in and glue them so they can’t move. There are cutouts and horn positions if you want to add flaps, but apparently no instructions or obvious way of fixing them if you don’t.

After that I had three more flights with the RS352. In between all of this, there was a guy with a drone filming a keep fit group. He was interesting to talk to as he’s just got his permission for aerial work. Talking to him, he said it was really easy to get and just required a lot of paperwork and a flight test. Near the end of the morning a family turned up with a white Piper Cub (see picture). The older kid was actually quite good at flying it, but it’s the little one launching that got me. The picture shows him having just thrown it into the sky.

We also had the EFlite advance and, just as I was leaving, another guy turned up with a flying wing. I only saw it flying from a distance, but, given the small holdall it came out of and the FPV kit, it may well have been a Bormatec Ninox?

I’m back to building micro drones now, when I really want to be finishing the AutoGyro. You can see the parts I’ve just had delivered above. I’ve got two sets of F3 EVO Brushed flight controllers and the generic FrSky receiver that the Eachine QX90 drone uses. I’ve also got four sets of our modified HubSan quads with 3D printed frames repaired and ready. This is for the “Drones Masterclass” that we’re running at the end of the month. The parts above are intended for an FPV micro drone that we’re going to try running a 3D reconstruction from.

Here’s an example I captured of the ATOM autogyro:

http://www.123dapp.com/fullpreview/embedViewer?assetId=6342729&size=medium

Here’s a link in case the 123d Catch embedding doesn’t work: [ATOM Autogyro]

Hopefully there’s going to be more on this project later.

Rain Stops Play

It’s been raining hard since about 7am this morning. If it does ever stop then it’s going to be because the wind has blown all the rain clouds away, so that’s no good either.

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So today’s going to be a building day, which is why I’ve included an image of the tail of my autogyro with its new starburst pattern. The blue and white looks really good and should be a great aid to orientation in the air. I just need to add the white lines and logo on the side and finish balancing and covering the blades.

On the subject of making the “ATOM” lettering for the fuselage, I traced the outline from the plan onto some white paper, cut around it with scissors and sellotaped the paper to a piece of solarfilm. Then I cut around the paper outline very carefully with scissors and the result was a very passable set of four letters. I just need to make sure I can tell which is paper and which is solarfilm when I iron them onto the fuselage. Solarfilm sticks, paper doesn’t. Seriously though, it did take a bit of manual dexterity, and cutting the hole in the “A” and the “O” with a knife, but it was very quick to do and produced four good letters.

I seem to be busy with too many other things at the moment, so the ATOM build is taking a back seat to work again.

 

This is Autumn

It’s blowing a gale this morning. Then it started raining. The type of light misty rain that means if you have to wear glasses to see the aircraft, like I do, then you need windscreen wipers. I’ve missed three weeks running because of the weather now.

Anyway, I’ve finally covered the AutoGyro. At least I think I’ve covered it. I’ve never know an aircraft like this. Normally you cover the bottom of the fuselage, then the sides, top, bottom of wing and top. There are so many awkward bits to cover on this that it’s taken ages, plus the 35 degree ambient temperature hasn’t helped. When I put it all back together I keep finding bits to cover that I hadn’t realised needed it. The front face of the main former holding the mast is a case in point. It’s highly visible because of the cut-out for the head control rods. I didn’t know whether to do it black or the silver blue colour, so I opted for blue in the end. With all the exposed wood, I don’t know what to cover and what to leave, so I’ve just been doing a bit at a time and then seeing how it looks the next morning. This is why it’s been taking so long, but it’s been quite fun to do.

I really like the silver blue, but I think I need some white trim in places. Now I need to put all the radio gear back in and make it work again. That only leaves the balancing and covering of the blades as the last major item.

Red Autogyro, Blue Autogyro

I’m a bit late this week as I’ve spent the day covering my ATOM Autogyro. There’s no flying this week as yesterday it was blowing a gale and this morning isn’t much better. It’s taken me a long time to get to the covering stage as it’s just been so hot recently that I couldn’t bring myself to plug the covering iron in.

As you can see, it’s taken me a long time to get this far and I’m not quite there yet. Normally you cover the bottom of the aircraft and it’s a nice and easy way to start, doing something that isn’t terribly visible and is square and flat. Not with this fuselage. I hadn’t realised how many compound curves there are to go around on the bottom. The sides were a piece of cake by comparison. It seems you never lose the knack for solar filming though, even after you realise that the blue metal flake film is partially transparent and is going to magnify every tiny little mistake. If you look at the tail closely, I’m disappointed at how visible the joins are. I was covering it using up my very last scraps of old (20+ years old) film and ran out on the top horizontal stabiliser surface. You can see the overlap where I’ve had to join three pieces together in a funny position. Oh, well, I’ll just have to get creative with the trim graphics. I still haven’t decided what colour to do the fin end plates or the blades, but that can wait for a bit. What worried me a little when I was covering the fuselage is just how top heavy it is. I’ve never covered anything like this before and it was so difficult to hang on to the thing as I was smoothing out the film as it kept trying to twist out of my hands. There’s just nothing to hang on to or rest flat on the work surface.

OK, so that’s the autogyro, but I’ve actually spent most evenings this week working on the quadcopter simulator. I’ve had a play around with a control system that could be used for automatic navigation. In the simulator I could just tell it to head in a particular direction at a certain speed and height and the controller would just get on with it. I was thinking that I could try out some of the synchronised manoeuvres that I’ve seen the GRASP Lab at Penn University put up on the Internet. I’m thinking of simulating it first as I’m currently lacking a vision system, but it would be interesting to explore what’s possible with some of the cheap hardware that’s around. In addition to this, I’ve been improving how the quadcopter flies in the simulator. It’s well worth having a look at the MultiWii rewrite controller in the Cleanflight code to see how it’s done on a real aircraft, but there are some subtle differences between that and how it’s done in a flight simulator. It’s all very interesting once you get into it and it’s making me think about whether I could construct something novel out of all this automatic control theory.

Easter Rain Day

It’s Easter Sunday today and the clocks went forward onto British Summer Time this morning, so I had already lost an hour of flying anyway. After the current run of good flying weather, it’s all been brought to a halt over the Easter weekend. So far this morning we’ve had gale force winds, torrential rain, thunder and lightening, hail and bright sunshine. I remember when I used to test fly my new models over Easter and could get several consecutive good days of flying in. One year I remember bringing a succession of Kyosho F16 EDF, Vampire EDF, Extra 300 and Flying Wing on different days to comments of, “I’ve seen you here four days running with four different models” from a guy I bumped into.

Needless to say, pressures of work mean I haven’t got the ATOM Autogryo finished yet, but I have made some progress with “Bob” who’s going to be flying it for me. You can see him here in the cockpit and I’m really rather impressed with how he’s looking. Bearing in mind I was intending to do a pilot with a helmet and then changed my mind after reading the RCM&E article on pilot models. This was about how you don’t ever see someone flying a plane in a motorcycle helmet like the ATOM prototype has, so I think it’s come out really well considering. I had already made the head helmet shaped, so added a cardboard peak for the baseball cap and painted the top of his head red. That worked, so I mixed some red and white and gave him pink skin. Later today I’m going to give him some blond hair, eyes, nose and a mouth. The eyes I can cover up with dark glasses, but I think the nose and mouth might be my undoing (scarf?). Anyway, I’ve got two weeks off work so I’m hoping I can finish this now and fly it when the wind finally drops. I have discovered a bit of a problem, though, in the way the motor wires don’t reach through to the speed controller. I’m going to need to make the hole in the firewall a lot bigger and just hope for the best. Other than a few awkward bits and pieces (and painting and covering), there isn’t much left to do but make it work.

As for doing any flying this Easter, I do have 18 batteries (yes 18) left over from the Royal Institution session we did a couple of weeks ago. That would give me quite a lot of flying time with the HubSan X4C, but I am starting to get really fed up with quadcopters. I want to do something unusual, so have a look at the 3D printed frame on the left in the picture below:

IMG_20160327_140802.jpg

Does it remind you of anything? Have a look at some of these images of an Eagle from Space 1999: https://www.google.co.uk/search?q=space+1999+eagle+images

That might surprise a few people if they saw it flying around. It’s an Eagle, NOT a Drone.