Balancing Act

I’ve no lift this week, so I would have had to go on the bike, but I spent all Saturday working and didn’t quite manage it. The weather forecast for this morning isn’t what I saw on the BBC last night either. When I got up it was bright and sunny, not overcast and cloudy as they forecast, plus the 6mph wind was a lot stronger. I’m going to have to consolidate all my weather forecasting tools and put them online now I can’t just watch it on the news any more.

After spending the week trying to fix my solarfilm iron, I’ve finally given it up and decided to buy a new one. First, I thought it was the oxidisation on the screw connections.


Half the ring is cleaned (shiny brass) and half isn’t (top).

Then, after I figured out how to get the handle off,  I checked out the diode rectifier.

The diode is fine, so by this point I had got down to the heating element at the very bottom of the iron. Running the continuity meter along the element wire I found the point where it had broken. This isn’t something that can be fixed because of the heat, so it would require a whole new piece of resistance wire. Now, while I was tempted to try replacing it with nichrome wire, common sense says spend £30 on a new one.



So, I’m now putting the autogyro back together as best I can, while not being able to solarfilm anything. This morning I’ve been working on the new blade.


It’s not easy to balance one of these blades, but I managed to get it to balance perfectly between two pins taped to some old 12v batteries. When I first made all four blades, I used a profile template cut out of 6mm plywood to make the airfoil. It took me a while to find this again, but it meant that I could run it up and down the span of the blade to get the profile identical to the other two remaining ones. Having cut the fibreglass hole reinforcements off of the broken blade, these are now ready to be glued in position once I work out where the mounting hole needs to be drilled. This is why I’ve been balancing the blade all morning, because the hole needs to go 1mm back from the balance point.

OK, that’s it for this week. I’ve not flown anything so far today, but I might have a go with a quadcopter indoors later on. This is what I should have done this morning, except that I should have put it in a ruck-sack and got the bike out. You never know, somebody might have let me fly a proper aeroplane?


The Universe Hates My Autogyro


I was making good progress building my autogyro last week, up until the point where my solarfilm iron packed up.


MacGregor Industries, my trusty old solarfilm iron, it worked for decades and then it stopped.


It must be over 20 years old, so I can’t really complain. I bought it at Sandown Park all those years ago and have been using it ever since. I spent the whole week trying to fix it, but I think one of the power wires is broken and I can’t figure out how to get the wiring out of the handle. I’ve removed the screw, but it looks like it’s glued inside. Oh, well, if I can’t do anything with it today then I’ll have to go out and buy a new one.

You can see from the pictures above that I’ve got the bottom and both fuselage sides covered and had just started on the top of the nose when the iron gave up the ghost. I’ve just got the nose, the fin outer sides and the trim to finish, then the new blade. I was almost there and then I got stuck, so I’m going to push on and fit any of the equipment that I can while I work out the covering situation.

As for the weather this week, it’s a beautiful bright and sunny day, just with a 30+ mph wind and sub-zero temperatures. I haven’t flown any real aircraft for ages.

Sun With Teeth

I’m told that “Sun with Teeth” is a common Greek phrase, but we also refer to a biting cold wind, so I can’t help but wonder how the similarity came about. Translating this into today’s meteorology we get, “it’s only sunny because the wind has blown all the clouds away”. Today is not a flying day, but then I really need a break after yesterday’s drone masterclass that we ran for thirty kids aged 12 to 13.



The drone masterclasses always take a heavy toll on equipment and the dragonfly was the first casualty, coming into contact with a window and then the floor. I’ve still got to go through all the equipment and test it, but it does look like we got more of it back than last time.

As well as letting the kids have a go at making and flying quadcopters, we also showed them an FPV drone.


I did design my own frame, but then found one on Thingiverse which was better and I was a bit short on time. My own frame flew for the first time on Monday, using some 75mm diameter props which I’ve had from Unmanned Tech Shop for a while now. The problem is that they just don’t work. On both the first test with my own frame and the second test on Tuesday with a different frame, the aircraft exhibited severe oscillations indicative of over-damping in the PID parameters.


These props caused severe oscillations.

Initially, I turned down the PID values, using just a low value “P” as a tuning base, but this made no difference. Having looked at the settings for an identical F3 EVO based quadcopter that worked, I ascertained that I was in the right area and switched to the standard HubSan 55mm diameter props (the black and green ones on the quad in the photos above). The problem was aerodynamic, but I’m not really sure why at the moment. I’ve got four packs of these things as they came with the motors, so I need to do some more investigations. The markings on them are very weird, having A1, A3, B1 and B4 on one set and A2, A2, B4 and B4 on another. I’m thinking that the pitch might be different and they didn’t realise and put them into the wrong packs? I have actually flown a bigger quad where I accidentally put the wrong pitch propeller on, but it didn’t exhibit this sort of severe vibration issue.

Anyway, that’s our current event over until the next one in March, so my time is my own again. Let’s go and fix an autogyro…


That’s Busy Building Quadcopters…

It’s too windy to fly this morning, but I’m really busy with the preparations for the Drone Workshop we’re running next week. Yesterday I got an EVO F3 Brushed flight controller working with Cleanflight and the new Frsky XM16 receiver I bought. This meant flashing my Taranis with the new EU LBT firmware, which was an experience in itself. I spent most of the day getting it to bind, then the rest of the day getting the SBUS to work to the flight controller. Eventually I got it all working, so now I need a frame. After finishing up yesterday making improvements to our existing frames, today I’ve moved on to designing a new one for the FPV quadcopter from scratch. I want to use the bigger propellers for greater efficiency, so I need a bigger frame than we currently have. I’ve spent all day trying to build this in FreeCAD and seem to be getting nowhere fast at the moment. We’ll just have to see how that one turns out in the end.

Raining Raining Raining Raining

Actually, I think it was snowing for a bit. Oh, well, it doesn’t matter anyway as I’m busy converting and fixing quadcopters for the next workshop in February.



I’ve been working on the Honey Bee model and managed to get the frame weight down to 13g, so it should fly well. The interesting part is where the air from the two front motors blows through the wing detail. On one of the failed prints I cut out some bigger holes which improved its stability in the hover. I might do a bit more tweaking around the aerodynamic flow to improve it a bit more, but it’s probably OK as it is. Then I’ve got 6 flight controllers to fix and about a dozen new motors. It’s been a long weekend with the soldering iron while the rain hammers down on the skylight.

First Flight of the Year

It was a very grey day, but hardly a breath of wind for once, so I finally made my first flight of 2018. Actually, I flew somebody else’s Ares Taylorcraft UMX plane first, having not flown since mid December. It appears I can still do it as I had four flights with the RS352 and another with the Taylorcraft. That is until the transmitter started making a really shrill beeping sound. We couldn’t figure out what it meant but thought it a good idea to land as it’s probably a battery warning. Whatever it was, it was really annoying me.

There were a lot of people around today. First, there was a new E-Flite Valiant flown by the guy who had the Fly Baby lookalike and Opterra wing. Another guy and his son were getting back into the swing of flying after a break as they had a new foam Spitfire waiting back at home. They were flying a Carbon Cub, but I think it was having some balance issues. On the first flight, a perfect take off from the ground was followed by a vertical climb, then left hand circles always losing height until it came back down to earth. It seemed to be tail heavy, so, after some fixing, the next flight was a lot better. I’m not sure if they’ll fly the Spitfire next though. We also had two guys, both with Mavics and a lot of FPV kit. One had a ZOHD Dart while the other was managing to fly a small T-Tail foam pusher around for what seemed like ages. Another Dart also turned up while I was leaving and I also saw another guy with his son walking across carrying a DJI Phantom drone. Apparently, there were a lot of them around right after Christmas. Anyway, the final drone flyer turned up with another Mavic, but couldn’t fly it because it had decided to do a firmware update. Personally, that puts me off ever owning one of those things.


As you can see, I’ve started re-covering the Autogyro. Unfortunately, I’ve run out of silver blue, so this one is going to be red up to the canopy line and blue on the upper sections. I’m not sure I like the red all that much, but it should look like my Extra when I put a white line along the join. I really just want to get it flying again at this point, but I’m currently trying to figure out where the best place to source the 0.8mm fibreglass head plate from. I also need to make another blade, so I’m not quite there yet. However, once all those bits on the table have found their way back into the fuselage, then I’ll feel like I’m almost finished.

Honey Bee

I can describe today’s weather very easily: bright and sunny, 20 mph wind, sub-zero wind chill. I’m staying inside as I’ve got loads of work to do anyway.



One thing I’ve been up to this week is 3D printing the new design for a “Honey Bee” quadcopter for the drones for good master class that we’re running in February. Later on I need to test out all the kit to see what’s left after the last lot of kids destroyed everything. The first flight of the honey bee will be the only flying I get up to today.


The Fuselage is Finished

The last day of 2017 and the weather is wild. Wind and rain makes it a building day, but I’ve finally finished the repairs to my autogyro’s fuselage.



It’s standing on its own two legs again, in amongst all the left over debris from the crash in October. All I need to do now is a bit of final sanding and then cover it. What I’m going to try and do, though, is to recover enough of the metallic silver blue film to cover the inside surface of the left fin. This blue film was left over from my first electric model, a Galaxy Models Aerojet from about 20 years ago. I used the last of the left over bits on the original covering, so I’m going to see if I can use some of the removed bits to cover the fin, using a bit of extra adhesive applied to the balsa first. This is so I don’t have to re-cover the whole tail section, as the right fin still has the blue on the inside and I’d rather not have to remove it, but two different colours would look decidedly odd. On the outside left and right fin, I’ll probably use something visible and different, like a bright red. The remainder of the fuselage will get the deep blue left-overs from my Extra 300. Anyway, that’s this afternoon’s job.

Here are some of the inter-repair photos on the tail end:


After the ply doublers had set, I sanded them back to expose some of the grain of the ply, as I really loved the look of the spruce grain longerons that I had just covered up. The ply grain doesn’t look as good as the spruce, but it will have to do for now.

As for the main part of the the fuselage, I finally relented and added some sensible 1/32 ply reinforcement to the inside where the two side pieces are grafted together:


There, that makes me feel like the fuselage isn’t going to snap in two. Now I’m going to use my covering iron on a low setting to try and peel away some of that remaining silver blue film to see if I can recycle it for the fin. Just in case you’re wondering why I haven’t removed the film on the fuselage bottom and sides before this point, I’ve always found that it acts as a useful protective covering while I’m doing any major work on an aircraft. Leaving the covering on can prevent a lot of dents and scratches that the exposed balsa can pick up on the workbench if you’re not careful, and, when you know the repair is probably going to take months, it’s a sensible precaution to take. As for accidentally dropping glue on the fuselage while you’re sticking the tail back together, nobody would ever be that stupid, but we all know that the glue won’t stick to the film anyway.

OK, so let’s see what scraps of film are still usable.

Wrapping Up My Presents on Christmas Day

Well, that’s the tail fixed and (almost) covered. The left fin has had two triangular fillets added for strength. The right hand half, which is still covered on the inside with film, I’ve decided to leave as it is. It already had a triangular fillet added on the top after the first crash. It’s a lot of effort to add a bit on the lower left, for no real benefit, so I’ve decided to leave it uneven. I fixed the top part of the right fin, so that will do. If you look at the left and right photos below, you’ll see what I mean:


Right, so now it just needs some covering on the vertical pieces, then I’m on to making a new rotor blade.


Merry Christmas 2017

Merry Christmas and a Happy New Year!

Here’s hoping that there’ll be a lot more flying done in 2018 and that I finish the autogyro repairs over the Christmas break so I can fly it again early in the new year. Who knows, I might even buy myself that little biplane I’ve been looking at?