Mechanics of flight

  • Thread starter Borek
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  • #26
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marcin_in_the_air.jpg
 
  • #27
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And a video...

 
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  • #28
CWatters
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Nice vid. I would suggest your plane is pretty well set up or you are compensating very well! No evidence of it pitching up or down with changes to the throttle so thrust line is probably spot on. No evidence of it dropping it's nose or pitching up in turns either. All you need now are some thermals.
 
  • #29
rcgldr
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It was way too windy and the model was dancing all the time.
Yeah if the wind is gusty, then the model is going to dance around like you mentioned. You'll need to get some flight time in where there is little or no wind, and whatever wind there is, a smooth wind, which will let you see how the model is trimmed (does it pitch or roll if you center the sticks?).

Since the Bixler 2 can handle a go pro, then there's no need to get a rudder elevator model.
 
  • #30
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which will let you see how the model is trimmed (does it pitch or roll if you center the sticks?)
In general it doesn't - or at least I don't see it being a systematic problem. Sure, lacking the experience I can miss something.

Before powered fly I just throw the model to see how it glides - and in most cases it flights nicely straight ahead. When it doesn't I trim it using the transmitter till it does. Gusts often make it difficult.

Since the Bixler 2 can handle a go pro
I have a feeling with a GoPro (additional weight and air resistance) it got more stable. Sure, it requires more power during flight, but it is not as sensitive to wind and steers as without the additional load.
 
  • #31
rcgldr
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I have a feeling with a GoPro (additional weight and air resistance) it got more stable. Sure, it requires more power during flight, but it is not as sensitive to wind and steers as without the additional load.
That might have moved the center of mass forward a bit, did you recheck it?

Video from the local hill site, mostly Radians which I mentioned before. All I had was a basic phone, so not a great video, but enough to get an idea that these are popular. Some of the guys were doing touch and goes off the carpet.

 
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  • #32
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That might have moved the center of mass forward a bit, did you recheck it?
Yes, I moved the battery to the back to keep the center of mass where it should be according to the manual, plus - as I do every time - I checked if it glides correctly before flying. Sure, I can be off by several millimeters, but not by much.

I think I moved the center of mass up though - but there is not much I can do about it.

Quite crowded place on your video, such flying requires precision that I can only dream about at the moment.
 
  • #33
rcgldr
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I think I moved the center of mass up though - but there is not much I can do about it.
Adding weight will speed up the model a bit and make it less sensitive to minor gusts.

Quite crowded place on your video, such flying requires precision that I can only dream about at the moment.
Since they are foamies, occasional collisions aren't going to do any harm, so they can flight in tight packs if the motors are off so the props don't do any damage. They were mostly using the updraft on the hill to stay up, and they landed rather than turn on motors to avoid doing any damage. For those that launched using motors they launched away from the pack, then motored off and glided back into the pack.
 
  • #34
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A short update - things are getting better, but I am still far from feeling confident. Actually I have a problem doing any of the tests we talked about earlier, as they require a stable flight to start with - and that's not something I see often. No idea if it is still a matter of gusts (last weeks were windy here, so it is quite possible) or something else, but the flight is shaky all the time despite my attempts at tweaking the trimming and whatnot.

Warszawa_z_powietrza.jpg


(the other file is a recorder flight path in text/xml format that can be opened with Google Earth - either change the extension to .kmz or unzip the file and use the .kml, works both ways).
 

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