Archive for April, 2011


Hello!

I was honoured by being invited to Balltorp field as a guest flyer. I could do my maiden flight there. I took my 2 keychain cameras (fixed on the plane) and my hat cam.

The maiden was divided in two parts actually. HaBoRC kindly offered me to have an instructed maiden and a demo before I do my actual maiden. As I was way too excited to fly I was glad to follow his instructions. We had an average wind with some sudden gusts, you can see the direction on the map in the video.

First HaBoRC checked the CG balance on ground. Was okay, I set it as good as I could. Then he took the plane up in the air and checked if it needs trimming. It was difficult to tell due to the wind, but looked neutral.

Then he checked if the plane is easy to land and drove around with it several times so that I can see how it reacts, how the sight changes with distance, how it “feels” up there. As he made some rounds I got calmed down (somewhat), and then we gave it a try.

I could choose between two options. Either HaBoRC takes off and handles over the radio in the air or I just take off myself. We took one round with the first option for the sake of safety. I landed the plane in the bushes at this point, drove it in the wind (against wind direction to minimise ground speed) and then “dropped” it from 1.5 meters into the higher grass. With a foam plane you can do that unless you do it from higher altitude. No damage on the plane, this time I did not dare to land on the real landing area.

Next time I took the cameras, set up everything during HaBoRC flew with his planes. Had one keychain camera on the nose of the plane. One under the wing, facing backwards and my trusted hat cam, that always gets some smiling faces when people see it. It looks “deeply professional” ๐Ÿ™‚

So unless you fell asleep in the first few paragraphs you can see that my maiden was actually several maidens together. The one that you see is a semi-maiden, I gained some bravery and went for it. This time I aimed for a proper start and a proper landing. I was extremely cautious with the wind. My fighter plane simulator experience echoed in my head along with the comments from HaBoRC.

You have 2 types of energy. Height and speed. You can convert one to another. Unless you are low on both you are mostly okay. If you have height and lose speed you can always convert some height into speed through diving. So I tried to fly somewhat higher and medium throttle. I have a 2200 kv motor in the plane with a 6×4″ propeller, this delivers insane power at full throttle. So I had reserve there. The bottleneck is my inexperience and my lack of control.

The control: what needed setting up was the radio actually. I needed to dial in some expo, so-called exponential setting. This makes the center of the yoke movements less sensible, you can control fine movements easily, there is no worry for hard inputs. And with full deflection you have full control surface action. I added 33% on all controls and 20% on aileron due to wind gusts. So I had less sensitive action on elevator, rudder, but a bit more sensitivity on aileron. This helped a lot as I explain it with my funny language.

I took several flights, 5 in total. Practiced round flights, some 8-figures and tried to turn left and right. The Easystar glides so well that I needed to extend my turns above the small lake so that I gain more length. Otherwise I glide over the whole field and cannot slow down.

Later the wind picked up and I almost crashed into the depo area. That one was tricky, I flew against myself and then I had to save it with low altitude and close distance to the obstacle. The camera doesn’t really show the distance due to the 28 mm wide lens setting but it was close enough for me.

This time I landed and decided that it is going to be enough for the day. I flew 5 rounds, gained amazing amount of experience and had great fun. I need to keep up the practicing, I need to have same respect towards the wind and the plane, I think.

Thanks again for the great instructions and the possibility for the flight as a guest.

I think I need to consider joining the club (www.mmflyg.se), flying is great fun ๐Ÿ™‚

Best regards,

Sir Crash a Lot

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Hello!

Happy Easter!

I thought of practicing with simulator again, need to prepare for Easystar maiden flight. For this I committed an A.A.S. what stands for Another Act of Soldering ๐Ÿ™‚

I had two flat type Li-Po batteries for transmitter usage, one is used in my helicopter radio, the other is a spare. Since the Lama v3 radio transmitter that I use for simulator control is without batteries right now (I used them up for the Turnigy 9X v2) I had to mod that radio. Now it features Li-Po as well.

Back to the practice, I tried to fly smoothly and after a while I tried to coordinate my turns with rudder while compensating with ailerons. I don’t say that I managed well but tried.

I also comment on my pilot errors, you can read my comments during flight.

I think I will practice more until next week, when I may do the maiden some day. This is getting exciting!

Best regards,

Sir Crash a Lot

Hello!

I was very careful to have all the wires and connections right, as I described in last post. Nevertheless I commited a stupid mistake, quite embarassing one.

Since the two halves of the fuselage are glued together it is good idea to go through everything before you actually glue togerther the fuselage. I had servo wire extension leads routed forward so that I can connect extra components later.

I wanted to connect the ESC directly into the receiver, however I connected it to the wrong channel. There is a “battery channel” above all the other channels. You may connect the ESC here for testing the servos, they will work fine. But you cannot operate the motor from here.

I noticed this when I connected everything and wanted to test the motor. It never beeped as it should be (telling the number of cells of the battery). Then I knew that I made wrong.

I was forced to cut open the fuselage, fortunately I marked where that cavity is located in the fuselage. So I cut a small brick out and could retreive the connector. Then I could replug it to channel 3 as it should be.

When everything was connected I did some testing again. Last time I haven’t actually checked if the ailerons are set right. They weren’t I had opposite travel on the aileron channels. If I launch the model so I perform the shortest maiden flight of them all, I would have crashed short after. Good to check everything.

I checked if the throttle channel was set right in the radio. With my previous test I assumed that it is okay, but better to check. So I connected the motor to the ESC and tried out some in the kitchen. My wife was doing her training, so she did not complain about the noise. (She doesn’t know yet that internal combustion engines are much louder and electric motors are considered as silent in comparison…)

So please find here my test installation and then my test recording. Made with a hat cam.

And the video:

I will need to set the canopy hatch and then the model is ready to maiden, I think. Maybe during next week this will happen. Very exciting.

Best regards,

Sir Crash a Lot

Hello!

Please find the follow-up of my build here. Last time I started with the actual build, now I shall tell you how I continued.

I intend to have an installation that does not require any future opening of the 2 fuselage halves. So I thought of using servo extension wires and lead all 8 channels forward.

I got into a dilemma: should I use one lead for the ESC even or not? I checked how the ESC lead would connect to the extension wire and was not 100% sure of the connection. So I went for directly plugging the ESC into receiver. That connection is solid. It would be a pity to lose the model do to a sloppy electrical connection.

I numbered the leads so that I can see which cable corresponds to which channel. Beautiful handmade numbering, of course ๐Ÿ™‚

I added some ballast weight in the rear. My experienced RC colleague raised this point to me, very important indeed! As I plan to have FPV gear in the front the plane will get nose heavy. So it is better to have weight in the tail and compensate with extra weight in the nose until I replace the front ballast with FPV gear. I am not sure if I did enough in the tail but more than nothing.

The receiver is going to sit on velcro tape. This will secure it to left side fuselage half. I tested the extra strong adhesive velcro on canopy to see if it will “eat” the foam (if it will get into reaction with the foam, to formulate this nicer). It did damage it, so I used my non-adhesive velcro and epoxy.

I taped together the fuselage halves and checked if my ESC wire is proper length. Guess what: Murphy worked again and it is too long. The ESC will get too far from the motor. I had to cut the wires and resolder (“sodder” for US ๐Ÿ™‚ )ย  the connectors. By-the-way I can see some marginal improvement in my soldering skills, although I am not really a soldering Paganini or similar…

There is a V-shaped cut in the fuselage, this will enable the cables to be routed in a channel. So when the canopy is attached they will not interfere. When I will have FPV stand there the cables can run behind that similarly. I hope this will work. If yes we might call this a great idea even ๐Ÿ™‚

Using the wing joiner rod I try to test mount the tail. It should be parallel to the main wings. There is a slight angle, I will try to correct this during the epoxy hardening process.

I glued on the tail, connected pushrods to stabilizers. Mounting test, everything is put together. Servos connected, motor is NOT connected. This is quite important, a live motor can be dangerous, only plug in your motor when you are sure of it.

Next picture shows my amazingly low budget balancing stand. I forgot how much those mineral water bottles cost, but since my wife buys them anyhow I could consider their purchasing cost zero in my modelling perspective. I had to fill them up though, so some water cost is there. Water is needed to stability, the bottles sit more solid this way.

I put the model onto the bottle caps and aligned them so that the center point will get 5 mm in front of rear seam of wing joiner cover. The manual shows this very clearly, you can check it there.

The manual of this model is truly excellent, the germans did great job with the design.

I had the battery in the nose (all the way to the front) and checked if it is easy to nudge the model out of balance. It was sitting quite okay. So I could clear the preliminary balancing.

Then I took the model on my fingertips and tried to balance it so. This is more accurate since the water bottle has a flat cap and my fingers are more round. (If somebody is suspicious: I am not showing fingers to anybody, no offense meant there…)

The video recording of all this can be viewed here, please.

I will need to put some coins in the nose as well, they will be standing in until my FPV gear will get sorted out. This concludes my balancing.

Best regards,

Sir Crash a Lot

Hello!

I would like to start with an announcement: after long preparations I started with the build. Or should I say “The Build!” maybe ๐Ÿ™‚

First I glued in the motor:

Then I glued in cockpit clip bracket.

Then I extended the rudder. Bigger size, Du-Bro hinges and clearance for the elevator. Made of 2 mm plywood, “carved out” with a screwdriver and a hammer. Yes, I worked like a caveman, really sophisticated way ๐Ÿ™‚

Notice that the rudder is not glued in place, the hinges are test mounted on picture.

Glued the tail, was very careful to have 90 degrees angle between stabilizers. I want to have a plane that is capable of flying straight.

Test mounting of radio receiver unit. Since the fuselage halves will be glued together I need a bullet-proof solution for the receiver. I thought of carving out some foam in front of it and having servo extension wires going into the front. So that when I will need the rest of those 8 channels I can just plug them in. And then I don’t need to tear down the foam fuselage.

I thought to have the ESC wires in front, slightly carved into the foam. So that when I shall have my FPV mount on place the cables won’t interfere with it. A future-proof build I intend to have.

I used a d 8,5 mm inner diameter plain washer to support wing retainer rod. So that the entry of the hole will not get sloppy with time. Epoxy glued it there.

I secured servo cables onto the wings with small blobs of epoxy. In case of damaged servo it can be removed with some dexterity. In normal use it will not allow the wires to vibrate. I left some length available so that I can connect to the connectors on the fuselage.

Rudder and elevator servos are glued in place. The cable channel could be used to glue there a 20 cm servo lead extension wire coming from the receiver. This will allow me to connect aileron servo leads coming from the wings with ease. Connector is solid fixed in fuselage, easy to connect to. I will mark polarity on the fuselage, ground wire is on bottom. As ground is usually.

Two half parts mostly done.

I even glued in the pushrod wires (bowden) along the fuselage.

Next I will need to locate the electronics to their respective location. The ESC and the receiver need a good fixation and wiring routing. I have a concept already, will develop it in detail.

This build is very exciting. I took my time with the wings and those small details that deviate from the standard build. I know that it is very difficult to have a perfect build from the start but I would like to get as few mistakes in my build as possible. We shall see how I manage.

Best regards,

Sir Crash a Lot

Hello!

Please find 3rd part of my aileron mod here.

Last time I cut out servo cavities and made all reinforcements in wings. This time I finalize servo mounting and pushrods (also known as piano wires).

I received comments from my experienced RC colleague, he pointed out that rotation point of aileron should be close to servo bracket rotation point. This meant that I had to reverse bracket, now it points forward. This enables more deflection on control surface.

I glued in servos finally. First I put heat shrink on servo, so that I don’t ruin servo itself with glue. This makes possible to change servo if needed.

I added glue on two faces only, in front and behind servo. This is not impossible to remove if I might ruin one servo later. Hopefully they survive though. I have metal gear servos, just in case.

Healing of glue. Kitchen table looks like a small-scale disaster when I am doing my work there. In 15 minutes I can clean up everything and restore full functionality of table. Tested ๐Ÿ™‚

In motion it would look like so:

I think that now the wings are ready for assembly, I can actually start building the plane now. Quite promising.

Best regards,

Sir Crash a Lot