Autogyro Repair, the Sequel

 

Well, true to my word, I repaired the autogyro back to flight ready status in a week. Unfortunately, the weather conspired against me. We had violent electrical storms the night before and forecasts of storms the next morning. Although it did rain quite hard, I’m not sure that the storms every really developed, but one place I don’t want to be is standing in the middle of a field holding a radio transmitter when there’s electrical activity overhead.

As for the repair, I stuck the spruce longerons back together again.

 

Then the fuselage sides got glued back together where the LiPo had moved forwards in the crash and separated them. You can just see in the picture below that I’ve also had to add a plywood plate where the spruce longerons meet the red fuselage. It’s just visible on the right of the picture and, if you compare to the area with the sellotape in the picture above, you should be able to make out the new 2mm plywood strengthening plates.

 

I’m a bit worried about making this area too strong, as it will eventually just break at the point where the spruce meets the fuselage. After that, I’ll be trying to dig the longerons out of the fuselage to replace them as they extend right up to the rear former.

Apart from sticking Pete the pilot’s head back on, the only thing left was the motor.

 

I probably could have bought a replacement shaft for the motor, but I chose to make my own out of a piece of 3.2mm rod.

 

You can see my new motor shaft at the bottom of the picture. It’s not quite perfect like the machined original above, but I made it and I like it better. Actually, it made me wonder what the commercial motor shafts are made from, as the original was obviously designed to fail rather than bend the motor bell in an impact. That didn’t exactly work and a shaft costs £3 while a brand new motor costs £10. My solid steel shaft is a lot stronger than the original, so one more hit on the ground like before and it’s going to be a new motor. I can live with that.

 

So there we are, one fixed autogryo and I’ve now got a whole week to properly test that everything works before committing it to the air again. Next time out I’m going to increase the shim under the rear of the blades to 0.8mm, which should reduce the lift and help with the launch.

That’s it for this week, but I did video the autogyro’s reconstruction last night, so I might post that later depending on how it came out. Let’s hope the conditions next week are more conducive to autogyroing.

Autogyrotations

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

 

 

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.

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:

 

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:

 

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?

Stuck Indoors

 

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.

We Won An Award!

 

I can’t believe it. On Tuesday we picked up an award for our work with the Drone Masterclasses.

Here’s looking to the next event during National Robotics week in July.

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.