Archive for October, 2011


Easystar 10th w1142

Hello,
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I had my 10th flight with Easystar, a nice number it is.
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This time we flew in really strong wind. I flew in constant steady wind at the sea, that is not easy but you can manage after that you get familiar with wind direction and strength. But same theory did not apply on Sunday. There was a steady wind of 6 m/s most of the time. But every now and then the wind just died to almost calm state, then we got some really strong gusts of up to 13 m/s speed. That was the challenge. Upon start and landing I had major difficulties, I am not at all comfortable with such strong wind. I did not crash the plane, but I had to fight for it several times.
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Prior to flying I changed propeller. I had a 6x4e pusher on, some cheap propeller from Hobbycity. It was not really well balanced from start and then I cracked it when one of my early start attempt ended up in a very low pass over the vegetation. It was so low that I actually flew straight across some tougher grass and the prop acted as a chopper for some brief time. This cracked the last half centimeter on one blade, so it wasn’t really healthy.
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I thought that I will be smart enough to try a 6x3e pusher prop. How hard can it be? It did not really work out. For some reason thrust is very low. It pushed the air backwards but just. Maybe I put it up in wrong direction, I have to check this more. Anyhow, right now I have maybe 2/3 of thrust at maximum. Maybe less. Starting the plane and flying it in that much wind was a major challenge. At some point I thought that wind is pushing it more backwards than I can get forwards. Since it was very turbulent I had difficulties flying straight, it was all over the place.
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Landings were extra tricky. When descending a sudden gust can take away altitude at alarming rates. A quick descent of 3-4 meters is likely. At low height this can mean plane in the lake for instance. So I was very careful above the lake. But no matter how careful you are, some unexpected event can happen easily with such wind speeds. Once I landed already, Easystar was skidding on the grass and slowing down. Suddenly a stronger wind gust liftet up the plane from the ground, since it was strong enough to temporarly simulate much higher speed of air flow around the wings. So even though that the plane was already landed it just took off.
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Another risky event happened at one of my starts. I am plainly rubbish at hand starting the plane, not much to sugar myself about it. Normally you should throw the plane into the wind. So you get more lift at low speed. Now I had reduced thrust on the propeller, my skills are slowly improving (but still being rubbish) and I had tricky wind conditions. I wanted to start, the wind just dropped, I had no good thrust to pull me out of trouble and I probably even threw it badly. So the plane just ricochet from the grass and then it could take off when the next wind gust helped it. A really chaotic takeoff it was. HaBoRC put some funny comment from the depot as you may hear 🙂
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I managed to try out my brand new 35 USD camera, that went without issues. Works like a bliss. In my video you can see the difference. I have a standard definition keyfob camera on the nose of the plane. It has a 180-degrees fisheye converter lens mounted. The Wing Camera from Hobbycity is a stock item, it comes with a nice wide-angle lens from the store as stock. So ready to use. If I count the price of SD keyfob + the fisheye converter I am already above the price of the HD Wing Camera, so choosing the former is just silly. The latter is much better value. You may see a comparison chart in my post from the other day.
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The footage I got with the new camera is simply amazing for me, now I can see much more detail. If I manage to fly this kit on a calm day the turbulence will not influence so much, so I can get really nice footage. Looking forward for some nice sunny and calm autumn day.
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There is one issue with HD resolution. The computer power you require for it is extreme. I have an old computer that was put together by no other than my humble self. This act of brave assembly happened late 2005, I bought some proven components that were already free of childhood inperfections. So I went for stability instead of power. I used following base components:
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– AMD A64 2200+ CPU
– Asus A8N-E motherboard, on Socket 939
– 1 gig of DDR-I ram
ATI X800GTO2 graphical card (a variant of X800XL) with 256 megs or VRAM.
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This was quite okay up to the time when HD appeared. On SD resolution it handles all tasks except gaming. But I don’t do gaming anymore. With HD it becomes a different story. HD videos don’t play on my computer without judder. Even 720p (1280×720) resolution drops frames while the computer struggles on 100% power. 1080p (or 1920×1080) is not even worth trying. It is just some frames every 10 seconds maybe. Hopeless.
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It is important to make some difference between playing an HD footage or processing it. Playing can be helped by some more modern graphical card that can take over computing. So even a low-end computer can handle playing it. But processing in a video processing utility is a different story. For that you need high power from the CPU, a lot of RAM and good data transfer on the motherboard. In short you need a modern computer.
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I made the editing anyhow and had a lot of waiting. When trying to align two video tracks for a picture-in-picture layout I am checking on the preview pane if the two frames are in roughly aligned. It is no professional work, if it plays within a half second I consider it already a pass. On SD footage this operation was already difficult, since my computer is low on performace. There were a lot of dropped frames, you had to sort of “lead” the cursor, move it and wait for the result before you let lose of the mouse button. With HD this is much worse. It takes several seconds for the preview pane to update. A simple play operation is meaningless, it takes seconds without picture update, then you pop up somewhere else on the timeline. Totally useless. The only way to work with it is to move the cursos very slowly and then wait for the result. I fought with it for 2 hours to get 4 pieces of picture-in-picture shots aligned. Very time consuming.
Rendering itself was surprisingly fast, despite HD clips the 8 minutes footage rendered in roughly 1 hour. Not so bad. I render still 640×480 resolution, maybe should try 720p rendering next time. I don’t know if there is so much to win about it in my case.
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What I would need is much more computing power. I read a lot of reviews and came to the conclusion that it is time to buy something that will last for some years in the future. Maybe not 6 years, we shall see how long I manage this time.
I set my eyes on the Core i7 architecture from Intel. It has 4 cores and all 4 can simulate 2, so alltogether you get 8 virtual cores. Despite being “only” quadcore it beats the respective offering from AMD by a good margin in video processing. In some test under Sony Vegas 9 it was almost 2x faster in rendering (compared to a 6 core Phenom II processor). So that is the aim, to have a really powerful CPU. I will target a lot of RAM even. Minimum is 4 gigabytes, but can extend later depending on needs. Considering the graphical card I don’t really have high demands. My favourit RC simulator shall run without glitch, that is the specification. I made some studies regarding this issue, checked homepage of the simulator and checked their recommendations. Also checked some Nightflyyer reviews about specs.
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We shall see how I manage. When I will get the new system running and I tested it I will try to get some comparison.
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Update 2011-10-30
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I tried out my 3-blade propeller. It is a Master Airscrew, 6×4 pusher. MA0640TP is the type of it.
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As a subjective feeling it gives more thrust than the 6×3 I had on during the last flight. I look forward to test it in real life. Made a short test video of it. Looks nice when the tail control surfaces get aerodynamically active at half throttle. Haven’t revved it over 2/3 throttle, it is quite loud in the living room 🙂
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Best regards,
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Sir Crash a Lot
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Hello,

I purchased a shiny new Hobbyking HD Wing Camera recently. Did test it but haven’t wrote a post yet. Now it is high time then.

This camera is slightly bigger than the simple keyfob camera. To summarize the parameters I can write a small comparison for you. HD camera first, SD keyfob second.

Resolution: 5 megapixel vs 0.3

Video resolution: 1280×720 vs 640×480

Memory card needed: Class 10 MicroSDHC (on both)

Price: 35 USD vs 15

Weight: 30 gram vs 15

Wide-angle lens: YES vs NO

Battery life: 2 hours vs 3/4

If you compare the two it is a no-brainer actually. To have decent wide-angle you have to get a converter for the keyfob camera. That jacks up the price to same level as the HD Wing Camera. And then image quality just decides on favor of the HD camera.

Using this camera is very easy. You can find the manual on Hobbycity homepage or just Google on RD32 camera. It is some sort of action camera, that is waterproof and you can mount it on your bike or cross buggy. Or whatever extreme sport you might do.

Appearently this is the same board, but no waterproof shell. Only the circuit board and some shrink wrap around. Hence the price. It is no GoPro, but does not cost 220 USD either.

I made some very simple comparison test. Had the old SD camera and the new HD camera in my hand and tried to pan them around.

I will need to try it out in flight as well. With some tweaks it can be used as FPV camera. Can record and broadcast same time. So quite a versatile unit.

Best regards,

Sir Crash a Lot

 

Hello,

I have two keyfob cameras from Hobbycity, the old SD resolution ones. Their code is #7, the worst of the lot actually. #3 was far better.

These cameras have a built-in battery, that is a 1-cell Li-Po with 140 mAh capacity. You charge it from USB-port. As far as I know traditional USB ports supply maximum 500 mA current. So this would charge up in roughly 17 minutes. I am very unsure how good the battery charging circuitry is in the unit. I would assume not so good. The premature death of my battery underlined this thought.

I was reluctant to just dispose the unit. It costs 15 USD, so quite cheap. But why dispose something if there is a chance of mending it. So I tried.

The idea was to buy a small Li-Po battery (done), and some JST connectors. So that I could remove the small battery, solder on the JST female connector and then use the external battery with some adhesive velcro tape. Brilliant 🙂

I tried to solder the contacts onto the wires. These wires are very thin, so use a fine grade soldering iron. Mine is very coarse, had to be very cautious.

When you have soldered the wire onto the metal pin you have to push together the last portion that forms an open U-shape. Otherwise it will not enter the plastic connector housing.

Then I had to remove some material from the other half of the housing. To have a good support for the connector I removed a rectangular area.

The connector fits nicely.

I double checked the polarity to be sure. Then I could assemble it and glue in the connector. It will be subject to some force when connecting and removing the outside battery. I used CA glue.

Just a size comparison, the new battery next to the camera unit. I will use adhesive velcro to fix it on top.

Maybe I will have the battery on the plane and the camera will sit on the battery. This way I will get better (less) drag coefficient. Important in flight.

I will need to do this on my other camera, that has reduced battery life. Probably will throw in the towel soon. Since this new battery is 240 mAh (vs 140 for the original) I will get significantly better battery life. And I can monitor the cell voltage with my Cell Voltage Monitor device. Important factor in keeping batteries healthy.

Best regards,

Sir Crash a Lot

Hello,

I would like to write a post about how to assemble Hobbyking Magnetic Prop Balancer device. It might look easy on the picture, but when you get to it you might find this helpful. Since no instruction manual is shipped, like in case of an IKEA furniture you need good assembly skills.

You will need to align the two sheets that have trapezoid shape and connect them with the U-shaped ones. Something like this.

For assembly you will need to slide the metal inserts and bolt them on with the small diameter screws. Please observe that only one side of the inserts is threaded, so you need to insert the screw from the mating side. This way you will have clamping force.

Then you will need to do so on the other side as well. You might need to peel off the protective paper layer. Depends on how tight the metal inserts are.

After this you can insert the big metal cup on one side. Secure it with the larger diameter screws.

One side is open, the other side is like a sunken cup. Into the open one you can insert the matching big cup. It is threaded, allows adjustment.

With the threaded cup:

Then comes assembly of panels.

Now comes the difficult part. You have to tear apart the 2 magnets. They are really strong. Do it carefully. When they are apart you can insert them into the cup features on both sides.

Between the two magnets should the axle float. The axle is pointy at the ends, so friction will be minimal.

Onto the axle you can slide the 2 conical rubber features. This will support the prop.

If I am right the rubber O-ring can sit on the adjustable side of the balancer.

When ready it looks like this.

A short video of how it does work.

Best regards,

Sir Crash a Lot

Hello,

I am proud to announce that I had my first proper crash. It comes sooner or later, you cannot avoid it. Mine came today.

We went out flying with HaBoRC, even though that the city was covered by fog. We thought that it might clear up during the day so we took our chance. When we arrived to the field conditions were far from perfect. I could hardly see the forest close to the field. I took a sweep recording, that shows a more cleared up view actually, in the beginning it was much worse.

Our initial activity involved recovering a plane that was crashed onto a tree some 7 meters high from ground level. We constructed a set of poles (taped together with Duck Tape, a special version of the famous Duct Tape actually 🙂 ). One member of our team was brave enough to climb up on the container containing gardening tools and nudged the plane down carefully. It was as slippery as ice, the fog made everything wet.

HaBoRC started to fly with his flying wing, I took off shortly after him. We agreed to fly close to the field so that we don’t lose sight of the planes. So did we. I started to turn tight so that the plane would stay in sight. I managed to make contact (collide) with the flying wing. I lost orientation of the plane (was extremely high adrenaline all of a sudden), to stabilize it I leveled it out. I was close to the lake, wanted to avoid it. Leveling out was good, but this enabled the plane to fly out of my sight, it went into the fog. I was desperate, tried to turn back blind but realised that with power on in the fog I will just smash it, so I chopped throttle and hoped for the plane gliding smoothly onto the fields.

What I managed I was unsure of. The very last moment I could turn away from the lake, that was good. But did it manage? Or is it in thousand pieces?

I started to walk into the generic location where it went lost. Unfortunately HaBoRC had similar problems. He looked at me fighting and forgot about his own plane. It went into the fog as well. We lost 2 planes within the first minute. Not good…

I walked along the small road and then discovered the plane. It was stuck into the soft vegetation covering the rocks. Pointing downwards, but the wings were on, control surfaces were on. Even the shape was normal. As I got closer I could see that it was gliding against a huge pine tree and ricochet to the soft bush. I could move the ailerons, elevator and rudder. Even the prop could spin up. The only thing missing was the canopy. I tried to find it but the fog was so thick that I couldn’t. I thought that it might popped off when I collided with the flying wing.

So I started to wonder around in the deep wet vegetation behind the field. My boots got totally wet, socks wet, then the trousers got wet even. Nothing. I thought that I might find it when the sun comes around. Recorded the others flying then I got back to the pine tree when the fog cleared up. And there it was my canopy. Close to the other big pine tree. That might took the first contact, the canopy popped off and then the plane crashed into the bushes.

The plane glided so far in the fog.

When I got back HaBoRC recovered his flying wing as well. I just tried to help him, wondered around the motorcross track and when I was back he had his plane as well. Great relief, I felt really badly after colliding in the air.

After a while I started flying again and could record some nice low passes. I still haven’t got my 2nd mini camera working, the replacement battery haven’t arrived yet.

Could record some nice multicopter flight. Quad- and tricopter. And some airplanes. I fetched some chocolate coated cookies, they were a welcome addition. Club members could replenish energy when needed. I will need to get some portable gas burner and make real coffee. Could a future project 🙂

Please see the recording of my flight here.

Hopefully soon I will get my Hobbyking Wing Camera and can get you much better looking recording.

Best regards,

Sir Crash a Lot