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Posted by mandevil | May 07, 2012 @ 04:02 PM | 4,318 Views
This weekend was the second extended 5-day weekend, but I went flying only once and used up only one battery.

Mostly I practiced basic aerobatics: rolls and inverted flying, with some attempts at "rolling ascents" (near vertical ascents with the plane performing rolls). Also, I tried to get hang of using brakes (ailerons extended up). They surely work, but they definitely make controlling the plane fairly finicky. It's very easy to exceed the stall speed with brakes on and then one may not have enough time to get the plane up to speed again, and it means the plane goes down hard. I definitely need more practice with brakes to actually be comfortable to use them to land in tight quarters.
Posted by mandevil | May 06, 2012 @ 02:49 PM | 3,961 Views
This is the first of the three videos in my editing pipeline -- not the best one, maybe it should be shorter, but I can't stand editing it any longer.

Střížovický vrch (Bixler / GoPro HD Aerial Video) (5 min 51 sec)

Posted by mandevil | Apr 27, 2012 @ 04:46 PM | 3,862 Views
I took a leave from work on Friday and spent much of the time flying. I have drained my set of three batteries twice. Great time.

As I mentioned, with the new transmitter I have full range on ailerons available. With this I can actually do rolls with Bixler and that was what I practiced a lot. Suprisingly, with some care and little help of headwind, one can make vertical rolling ascents. Impressive.

I also have mixed rudder into ailerons and set up differential ailerons. Honestly, I don't see much difference.

I also shot aerial video on two location and have one in backlog from the last weekend. Good stuff is coming, especially the last video looks much more stable than all previous ones.
Posted by mandevil | Apr 22, 2012 @ 06:14 AM | 6,874 Views
Yesterday I took my Bixler to test my new FlySky TH9X transmitter. Conditions were rather windy, making the plane's handling quite difficult at my first location. Then I moved to different place, which was as windy as the first. On the last flight I managed to soar for 11' 40" after one minute climb. I just kept flying into the wind with no attempts to circle. I guess there must have been some thermal in there, despite it being almost 7pm. Funny thing.

At any rate, the TX works fine. For the benefit of very first timers I detail the basic setup I did prior the maiden flight below.

1. The first step was to make ailerons work. I use two-channel aileron setup, with ailerons on the usual channels 1 and 6. The first 4 channels are default, the channel 6 needs to specify source AIL. Also I needed to reverse ailerons and rudder, which is done by setting their values to negative.

2. The next step was finding a way to be able to cut off throttle and make this default after the TX is switched on. Well, turns out that ER9X has specific function for this: "Safety switches". So I specify a setting for channel 3 (throttle), that makes the TX override the channel value with -100 when throttle switch is in OFF position (that's the !THR). Optionally, you can enforce the position of this switch on power up (in screen 2)

...Continue Reading
Posted by mandevil | Apr 20, 2012 @ 11:03 AM | 3,953 Views
Yesterday I picked up my FlySky FS-TH9X. It now has the latest stable ER9X firmware, programming connector outlet in the body and also processor-controlled back-lit display (which is really good investment, the readability in indoors is way way better).

Hopefully I set it up today for tomorrow's flight test!
Posted by mandevil | Apr 11, 2012 @ 06:22 AM | 3,574 Views
So this is second week of no flying. The last time I forgot to take wing spar with me, this time it was too windy. Too bad.

During the last week I received new radio, the SkyFly FS-TH9X (from Giant Cod, really quick delivery). I am little underwhelmed, the quality isn't that great (the display glass fell off, the battery compartment cannot be closed with AA batteries, the original software has lot of limitations). I switch the TX to mode 1 and used the AA battery cage connector to attach LiPol 2500 mAh TX battery. The last mod to do is, of course, to flash ER9X software. But I cannot really do this myself as I a) don't have the ISP programmer and b) I really don't know how to solder the cable necessary for the flashing. Therefore I'll use the service of more experienced guy to do this.
Posted by mandevil | Mar 25, 2012 @ 04:41 PM | 3,266 Views
Last weekend I cracked Bixler's tail. So during week I glued the crack and applied hot water. There still remains some bend, but it's fairly minor I don't think it has any bearing on actual flight. Also, I glued 3 mm carbon rod into the groove in the bottom of the fuselage with epoxy resin. Never worked with epoxy before, but it seems to hold fine.

OK, repaired plane goes to the nearby slope on Saturday. There's quite fresh wind and I go on slope soaring for the next three hours. I mostly try to just soar, with only occasional bail-out with motor. I try to get the hang of slope soaring, I try quick turns along the slope edge (no, that doesn't seem to go very well with Bix, I don't seem to be able to do them fast enough and I lose lot of altitude, I try to do gentle circles (seems to limit altitude loss, but wind is often too turbulent and changable to do this well), I try to keep plane afloat at all cost, as if I don't have motor (which inevitably leads to crashes when I try to turns when too low or too late). At any rate it's fun and learning experience. I only use about 600 mAh of battery, I'd say about 80% of the flight time is completely unpowered. I probably could use little stronger wind with more intense lift. Bixler is no fast glider so you really cannot gain too much kinetic energy from the wind, which limits its slope abilities.

My girlfriend was kind enough to shoot some nice in-flight pictures. See more pictures in gallery.

When I was almost ready to...Continue Reading
Posted by mandevil | Mar 18, 2012 @ 04:34 PM | 3,246 Views
On Saturday I did some video flying under castle ruin Blansko and took about 25 minutes of footage, but unfortunately, it doesn't appear to be any good. I have no idea why, but the flight is very jerky. It's as if the plane is constantly being upset by something. With my previous plane (which had the exact same airframe) the flying seemed smoother (though still far from ideal).

On Sunday I took Bixler to a slope. I didn't expect slope soaring, but actually the wind was fairly favourable and I managed to keep the plane in air for a while. After some time I noticed that both my ailerons are little up -- both the same amount. This looked strange and I suspected something wrong with servos. I readjusted the clevis/pushrod linkage, but after more flying the ailerons were up again, this time little too much for comfort. I thought the session's over and started packing, but then an idea flashed in my head. I turned the right knob on my TX and indeed, both ailerons raised and lowered as the knob was turned. I completely forgot that I still have active setting, that allows to adjust the ailerons symetrically when the right switch is on (that is either as spoilerons or flaperons). Oh well, I readjusted the aileron linkages again and continued flying. Unfortunately the wind was quite changeable and I suffered few light crashes. It all ended up when I discovered that my tail is crooked from a crack in the rear of the fuselage.

Note the raised ailerons. This was the moment when I decided that something is seriously wrong and decided to stop flying.

This is how I ended the day; the crack in fuselage is barely visible right below the horizontal stabilizer on the right side. Inevitable when you fly too carelessly.
Posted by mandevil | Mar 13, 2012 @ 05:59 AM | 3,378 Views
On Saturday I did some powered flying, mostly training catching the plane on landing (with not that much success). I discovered quite strong tendency of the plane to turn to left with high throttle. Nothing unmanageable, but fairly noticeable. The wings have tendency to unlock on harder landings and also catching the plane by wing is not good thing to do, but the wings seem to hold well during flight.

On Sunday the wind seemed to be quite strong, so we went to a nearby slope. Even if the wind direction wasn't optimal, there was lot of lift there and it was fun soaring for about 20 minutes. Then the wind picked up enough that I started to have problems staying on the upwind side and also worried about the integrity of the plane as I saw it being buffeted by strong gusts. Fortunately I managed a perfect landing by snatching the plane from air in mid-flight. Quite a stress test, but a successful one.
Posted by mandevil | Mar 04, 2012 @ 01:49 PM | 3,537 Views
Today we went to a slope and tried some soaring. There was some lift, but not enough to sustain flight, though paragliders were soaring nicely nearby. Maybe the spot I was on wasn't very good. I also crashed a little, but nothing got broken. Then we moved to another location and after quick test I put on my GoPro HD Hero and spent rest of the time flying with the camera attached. I made some 45 minutes of footage (on two batteries). Flying was OK, nothing unexpected happened (apart from my accidental switching off throttle and gliding to unexpected landing), wings were holding just fine, even ESC wasn't sliding off its velcro strip. Great.

Unfortunately, the footage is quite disappointing. The flight is very unsteady and I don't have good idea why it is. I reviewed my previous raw videos and they are definitely steadier. My hope is that the wind was rather gusty and that flying in better conditions will yield better video, but I'm bit dubious about it. Well, I have to wait and see.

I'll post the video when it's ready (that's gonna be at least several day, just first pass of Deshaker is about 6 hours).

BTW, I used up 4150 mAh (in three batteries).
Posted by mandevil | Mar 03, 2012 @ 03:47 PM | 3,360 Views
So finally, weekend is here, so I get ready my new Bixler (after gluing back aileron control horn that came loose after I hand-forced servo... aehm). It's been sunny, but windy and chilly. I made number of launches, testing various modes of flight. Relatively strong wind made it impossible to do any fine-tuning. I tried some aerobatics (loops, inverted flight). My main concern was if the wings are held together sufficiently well. Well, on about two occasions, the wings became partially unlocked, though not completely loose. At home I discovered, that one of the magnets is unglued. So I glued it back and we'll see. Maybe I will need to add more magnets, maybe I need to try something better.

Another little thing is that I use stick-on velcro to hold ESC in place. Unfortunately, the glue starts to flow when ESC gets warm/hot and the ESC gradually slides off the velcro. I used some CA glue and we'll see what happens.

As for the motor performance (Turnigy 2826 2200 KV): I haven't flown my previous plane for half a year so I cannot do a good comparison, but I would expect a little more from motor that has some 140 W of rated performance more. It's hard to evaluate the climb rate with ever present wind, but it doesn't seem to be that radically better. Sure, it's got a lot of power, but it's still not vertical climb. We'll see when I get some calmer day.

Posted by mandevil | Feb 26, 2012 @ 04:21 PM | 2,988 Views
Completing the Build

"We're going to fly it on Sunday!" said my girlfriend on Friday. Well, if she says we'll fly it, you bet we will. Better to get working on the plane again. I haven't done any work during the week, so the weekend was the only time remained.

First I glued in ailerons servos. No problems there, but I discovered, that the push rods I ordered are completely ridiculous -- they might find some use in full size jet fighter, but not in Bixler. They were too thick and extremely stiff -- and of course they did not fit into servo arms. Oh well, I'm sure I ordered them following some list of supplies posted here on RCgroups. Never mind, I will use the original push rods and clevises.

Other job was extending leads from ESC to motor. After some discussion on local forum I decided to disregard all the advice (overwhelmingly in favor of soldering the whole cable run without any connectors at all) and I made set of extension cables. Sure, it's sub optimal, but with my soldering skills it is surely better than trying to solder the whole thing in one.

Now, time to glue in the motor. This was one thing I wasn't completely sure about, as I discovered that snug fit of the supplied plywood firewall means there's quite noticeable axis offset to the right. At first I thought I must do something about it, but then I reread the manual to my previous SkySurfer clone (real manual, not that rag Hobby King includes with the plane) and they specifically mention the...Continue Reading
Posted by mandevil | Feb 19, 2012 @ 04:09 PM | 2,975 Views
Today I continued building my Bixler.

First thing was to glue servos to the fuselage halves. It sounds like 10 minute job, but it wasn't easy at all. The main trouble was attaching the elevator and rudder control wire to the servo and to be, at the same time, able to screw in the servo arm. On the first servo I decided to unbend the "z" bend in the wire, but it is so stiff, that I barely managed to bend it back. On the other servo, I discovered, that it's better to thread the arm on the wire first, than manoeuvre the servo so that the screw can be tightened through the hole in the fuselage. The HXT-900 servos are not pefect match for Bixler and some cutting of EPP is necessary. For which I don't have the right knife, so I was using clumsy cardboard cutter. I glued the servos in with two-sided tape used for mounting mirrors and some smaller amount of hot glue for added security.

This is how the result looks like:

For the wings servos (ie. ailerons), the three-lead servo wire is too short, so extension must be made. After some deliberation and with some input from others, I decided not to bother with servo connectors and cut the existing servo wire and solder the wire in the middle. Seems easy, but for a neophyte hobbyst it was two hours job, since there were 12 soldered joints. This is how it looks:

Preexisting three-wire servo cable is cut, each cut about 1 cm apart.

...Continue Reading
Posted by mandevil | Feb 18, 2012 @ 04:01 PM | 2,550 Views
So, finally, I started building my Bixler. I am complete neophyte as actual building is concerned, so it is going to be a journey of exploration and learning.

The first thing to learn about is soldering. As the Turningy 30A ESC doesn't have any connectors on it's leads, the first task is obvious. Fortunately, my girlfriend gave me all I need for soldering as a Christmas present (I didn't know anything about it, she looked up everything). So I have nice soldering station plus all the supplies and utensils.

My motor, Turning D2826-6 2200kv outrunner, has 3,5 mm connectors on it, so I soldered matching female parts. These hollow connectors were no problem, just heat them up until solder melts, fill them with it and then sink the leads into the molten solder.

The other end, towards the battery, was a little more difficult. I use XT60 connectors for batteries, so I started heating the metal piece for the same process as with the 3,5 mm connector. It took forever and the result was, that the plastic of the connector melted and the metal pin became dislodged. Oh well, next time I solder the connector with the opposite piece plugged in and by simply melting the solder directly and filling the cavity with the melt.

After I was done with soldering, I needed both to verify my soldering job and to bind my new receiver with my transmitter (remember, I lost my plane, so the RX was lost as well). Amazingly, everything worked without a hitch, binding was successful, motor works, all the HXT-900 servos work. Looks like I am all set for further assembly.

For tomorrow, I'm planning extending servo cables. I have yet to decide whether I will try to make new connectors or will cut the existing cable in the middle and solder the wire in the middle. The other thing I'm considering is to stiffen the horizontal tail surface with a carbon rod.
Posted by mandevil | Jan 11, 2012 @ 02:29 PM | 2,746 Views
Finally used the weekend to edit my last video from my Beta 1400 (my previous RC model that I crashed on a tree) -- it's from August 2011. You can watch it on YouTube here, but seriously, if you want sharp video with sound in-sync, do yourself a favour and download this 80 MB file. For some reason YouTube not only reencodes the video to look like crap, but it also desyncs sound.
Posted by mandevil | Dec 24, 2011 @ 08:10 AM | 2,741 Views
As I wrote on the day before yesterday, my two Bixler kits have arrived. Well, yesterday I managed to cut my left thumb while packing Christmas presents. The cut bled like hell and it took some suturing. Unfortunately that means I will be impaired for about two weeks and so the building of my plane will have to wait.

Anyway, I unpacked one of the boxes to see what's actually included. I was mainly worried about motor mounting and here I was pleasantly suprised: included is assembled plywood firewall with holes and screws that fit my motor (Turningy 2826). But there's but -- the motor itself doesn't fit into the pylon. So it looks like the only option is mount it so it is outside of the pylon (or maybe only partially outside, we'll see). After checking the mounting, I noticed, that the axis of the firewall is quite off the fuselage axis -- slight off-axis angle would be probably OK, but this looks like way too much. I'll see how I go about this.
Posted by mandevil | Dec 22, 2011 @ 04:30 PM | 3,199 Views
Two days before Christmas, two Bixler kits have finally arrived. So it looks like I will be able to start building the plane during the holidays.
Posted by mandevil | Dec 01, 2011 @ 06:42 AM | 2,974 Views
Yesterday, another package arrived - this time it was package with three LiPoly batteries from Hobby King German store. That was the package that originally contained two Bixlers, that after long time I was forced to remove from the order and reorder them from Hong Kong. That package is already on its way as well. So maybe I'll have everything before Christmas, if I'm lucky.
Posted by mandevil | Nov 25, 2011 @ 03:42 AM | 2,811 Views
Today, exactly two months after ordering, the first package from Hobby King arrived. It contains parts I will use to build my Bixler. Among other there is ESC (Turning Plush 30A), outrunner motor (Turningy D2826-6 2200 kV), replacement receiver for my HK-T6A TX.

The other package containing two Bixler kits and batteries is still on hold since Bixlers are back-order in Germany store. I'm going to cancel that order today and reorder from Hong Kong (which will incur extra cost and delay due to customs, sigh). At any rate, I will be lucky to start building in January.